diff --git a/.gitignore b/.gitignore
index cdedf00..eff5848 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,7 @@ Thumbs.db
 *.tar
 *.gz
 /rdev-api
+/sdlc
 coverage.out
 
 # Temporary files
diff --git a/CLAUDE.md b/CLAUDE.md
index 03b9602..ea60f1d 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -33,6 +33,7 @@ Run Claude Code instances in isolated Kubernetes pods with REST API control. Ena
 | **Redis operations** | [services/redis.md](.claude/guides/services/redis.md) |
 | **DNS / Cloudflare** | [services/dns-cloudflare.md](.claude/guides/services/dns-cloudflare.md) |
 | **Network policies / internal routing** | [ops/networking.md](.claude/guides/ops/networking.md) |
+| **SDLC orchestration** | [services/sdlc.md](.claude/guides/services/sdlc.md) |
 
 ## Critical Rules
 
@@ -108,7 +109,9 @@ curl -H "X-API-Key: $RDEV_API_KEY" $RDEV_API_URL/work/stats
 
 ```
 cmd/rdev-api/          # Entry point, DI, OpenAPI spec
+cmd/sdlc/              # SDLC CLI binary (runs inside project pods)
 internal/
+├── sdlc/              # SDLC library (types, classifier, state I/O)
 ├── domain/            # Pure business models (no deps)
 ├── port/              # Interface contracts
 ├── service/           # Business logic orchestration
@@ -163,6 +166,7 @@ cookbooks/             # End-to-end workflow guides
 | Database Provisioning | **Done** | CockroachDB adapter with auto-provisioning |
 | Cache Provisioning | **Done** | Redis ACL-based adapter with auto-provisioning |
 | Build Orchestration | Planned | Structured build specs via API |
+| SDLC Orchestration | **In Progress** | Deterministic feature lifecycle with classifier engine (library + CLI done, rdev API pending) |
 | Composable Monorepo Templates | **Done** | Monorepo skeleton + component templates (service, worker, app-astro, app-react, cli) |
 
 **Current Version:** v0.10.25
diff --git a/ai-lookup/index.md b/ai-lookup/index.md
index e7fdb38..fa0b841 100644
--- a/ai-lookup/index.md
+++ b/ai-lookup/index.md
@@ -22,6 +22,8 @@ Quick reference for rdev concepts and facts.
 | Infrastructure Management | [features/infrastructure.md](./features/infrastructure.md) | High | 2025-01 | Gitea, Cloudflare, deployment |
 | Build Orchestration | [features/build-orchestration.md](./features/build-orchestration.md) | High | 2026-01 | Bot-driven build specs with audit trail |
 | Composable Monorepo | [features/composable-monorepo.md](./features/composable-monorepo.md) | High | 2026-01 | Monorepo skeleton + component templates |
+| **SDLC** |
+| SDLC Orchestration | [services/sdlc.md](./services/sdlc.md) | High | 2026-02 | Feature lifecycle, classifier engine, rdev API integration |
 
 ## Roadmap Reference
 
diff --git a/ai-lookup/services/sdlc.md b/ai-lookup/services/sdlc.md
new file mode 100644
index 0000000..ffea6fa
--- /dev/null
+++ b/ai-lookup/services/sdlc.md
@@ -0,0 +1,88 @@
+# SDLC Orchestration
+
+**Last Updated:** 2026-02
+**Confidence:** High (Steps 1-5 implemented, Step 6 pending)
+
+## Summary
+
+Deterministic feature lifecycle management. Classifier engine evaluates priority-ordered rules to determine the next required action. State lives in `.sdlc/` directory (git-tracked). Used by Claude agents in pods (CLI) and by rdev API (Go library + kubectl exec).
+
+**Key Facts:**
+- 10 phases: draft → specified → planned → ready → implementation → review → audit → qa → merge → released
+- 24 classifier rules, first match wins, returns Classification with action + guidance
+- 7 artifact types: spec, design, tasks, qa_plan, review, audit, qa_results
+- rdev drives transitions on behalf of users (approve, reject, unblock, transition)
+- Multi-project: scoped by projectID (pod name), each pod has its own `.sdlc/`
+
+**File Pointers:**
+- Library: `internal/sdlc/` (types, state, feature, classifier, rules, config)
+- CLI: `cmd/sdlc/` (cobra commands, --json output for API consumption)
+- Port (planned): `internal/port/sdlc_executor.go`
+- Adapter (planned): `internal/adapter/kubernetes/sdlc_adapter.go`
+- Handler (planned): `internal/handlers/sdlc.go`
+- Spec: `docs/specs/sdlc-orchestration-system.md`
+- Guide: `.claude/guides/services/sdlc.md`
+
+## Library Types
+
+```go
+// internal/sdlc/classifier.go
+type Classification struct {
+    Feature      string       `json:"feature"`
+    CurrentPhase FeaturePhase `json:"current_phase"`
+    RuleMatched  string       `json:"rule_matched"`
+    Action       ActionType   `json:"action"`
+    Message      string       `json:"message"`
+    NextCommand  string       `json:"next_command,omitempty"`
+    OutputPath   string       `json:"output_path,omitempty"`
+    TransitionTo FeaturePhase `json:"transition_to,omitempty"`
+    TaskID       string       `json:"task_id,omitempty"`
+}
+```
+
+## CLI Commands
+
+```
+sdlc init                              # Create .sdlc/ structure
+sdlc state [--json]                    # Full state dump
+sdlc feature create <slug> <title>     # New feature
+sdlc feature transition <slug> <phase> # Phase transition
+sdlc feature block/unblock <slug>      # Blocker management
+sdlc artifact create/approve/reject    # Artifact lifecycle
+sdlc task add/start/complete/block     # Task lifecycle
+sdlc next [--for <feature>] [--json]   # Classifier output
+sdlc query blocked/ready/needs-approval # Queries
+```
+
+## rdev API Endpoints (Planned - Step 6)
+
+```
+GET    /projects/{id}/sdlc/state
+GET    /projects/{id}/sdlc/next
+GET    /projects/{id}/sdlc/features
+GET    /projects/{id}/sdlc/features/{slug}
+POST   /projects/{id}/sdlc/features/{slug}/transition
+POST   /projects/{id}/sdlc/features/{slug}/artifacts/{type}/approve
+POST   /projects/{id}/sdlc/features/{slug}/artifacts/{type}/reject
+POST   /projects/{id}/sdlc/features/{slug}/unblock
+GET    /projects/{id}/sdlc/query/blocked
+GET    /projects/{id}/sdlc/query/ready
+GET    /projects/{id}/sdlc/query/needs-approval
+```
+
+## Feature Gaps (Step 6)
+
+| Gap | Description | Effort |
+|-----|-------------|--------|
+| Port interface | `SDLCExecutor` port for pod operations | Small |
+| Pod adapter | kubectl exec wrapper for sdlc commands | Medium |
+| Service layer | Business logic, validation, error mapping | Medium |
+| HTTP handlers | REST endpoints under `/projects/{id}/sdlc/` | Medium |
+| Cross-project view | Dashboard of all project SDLC states | Small |
+| Webhook events | SDLC phase transitions as webhook events | Small |
+
+## Related Topics
+
+- [Kubernetes Adapter](./kubernetes.md) - Pod execution pattern (PodGitOperations)
+- [Work Queue](./work-queue.md) - Task execution for agents
+- [Worker Pool](./worker-pool.md) - Agent pool management
diff --git a/cmd/rdev-api/main.go b/cmd/rdev-api/main.go
index 63f91c4..9bc48da 100644
--- a/cmd/rdev-api/main.go
+++ b/cmd/rdev-api/main.go
@@ -241,6 +241,10 @@ func main() {
 	// Create build service (orchestrates build submission and tracking)
 	buildService := service.NewBuildService(workQueueRepo, buildAuditRepo, logger)
 
+	// SDLC lifecycle management (kubectl exec into project pods)
+	sdlcExec := kubernetes.NewSDLCExecutor(kubernetes.SDLCExecutorConfig{Namespace: namespace, Logger: logger})
+	sdlcService := service.NewSDLCService(sdlcExec, projectRepo, service.SDLCServiceConfig{Logger: logger})
+
 	// Create app
 	app := api.New("rdev-api",
 		api.WithPort(cfg.Port),
@@ -368,6 +372,8 @@ func main() {
 	buildsHandler := handlers.NewBuildsHandler(buildService)
 	createAndBuildHandler := handlers.NewCreateAndBuildHandler(projectInfraService, buildService, logger)
 
+	sdlcHandler := handlers.NewSDLCHandler(sdlcService, logger)
+
 	// Initialize operations handler (for debugging project failures)
 	operationsHandler := handlers.NewOperationsHandler(operationRepo)
 
@@ -398,6 +404,7 @@ func main() {
 	buildsHandler.Mount(app.Router())
 	createAndBuildHandler.Mount(app.Router())
 	operationsHandler.Mount(app.Router())
+	sdlcHandler.Mount(app.Router())
 
 	// Start queue processor worker (per-project command queue)
 	queueProcessor := worker.NewQueueProcessor(
@@ -415,9 +422,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	// Start work executor (cross-project worker pool)
-	// PodGitOperations runs git commands inside the pod via kubectl exec.
-	// This ensures deterministic post-build commit/push instead of relying on LLMs.
+	// Start work executor (cross-project worker pool, git via kubectl exec)
 	var podGitOps *worker.PodGitOperations
 	if infraCfg.GiteaToken != "" {
 		podGitOps = worker.NewPodGitOperations(worker.PodGitOperationsConfig{
diff --git a/cmd/sdlc/cmd_artifact.go b/cmd/sdlc/cmd_artifact.go
new file mode 100644
index 0000000..4477bbb
--- /dev/null
+++ b/cmd/sdlc/cmd_artifact.go
@@ -0,0 +1,195 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var artifactCmd = &cobra.Command{
+	Use:   "artifact",
+	Short: "Manage feature artifacts",
+}
+
+var artifactCreateCmd = &cobra.Command{
+	Use:   "create <feature> <type>",
+	Short: "Create an artifact file (sets status to draft)",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, artTypeStr := args[0], args[1]
+
+		artType := sdlc.ArtifactType(artTypeStr)
+		if !sdlc.IsValidArtifactType(artType) {
+			return fmt.Errorf("invalid artifact type: %s (valid: spec, design, tasks, qa_plan, review, audit, qa_results)", artTypeStr)
+		}
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		// Create the artifact file if it doesn't exist
+		path := sdlc.ArtifactPath(root, slug, artType)
+		if _, err := os.Stat(path); os.IsNotExist(err) {
+			if err := os.WriteFile(path, fmt.Appendf(nil, "# %s: %s\n\n", artType, f.Title), 0o644); err != nil {
+				return fmt.Errorf("create artifact file: %w", err)
+			}
+		}
+
+		// Update manifest
+		art := f.GetArtifact(artType)
+		if art == nil {
+			art = sdlc.NewArtifact(artType)
+			f.SetArtifact(artType, art)
+		}
+		art.MarkDraft()
+
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{
+				"feature":  slug,
+				"artifact": string(artType),
+				"status":   string(art.Status),
+				"path":     path,
+			})
+			return nil
+		}
+
+		fmt.Printf("Created artifact: %s/%s\n", slug, artType)
+		fmt.Printf("  Status: %s\n", art.Status)
+		fmt.Printf("  Path:   %s\n", path)
+		return nil
+	},
+}
+
+var artifactApproveCmd = &cobra.Command{
+	Use:   "approve <feature> <type>",
+	Short: "Approve an artifact",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, artTypeStr := args[0], args[1]
+		artType := sdlc.ArtifactType(artTypeStr)
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		art := f.GetArtifact(artType)
+		if art == nil {
+			return sdlc.ErrArtifactNotFound
+		}
+
+		art.Approve("user")
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		// Record in state
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+		state.RecordAction("APPROVE_ARTIFACT", slug, "user")
+		if err := state.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{
+				"feature":  slug,
+				"artifact": string(artType),
+				"status":   "approved",
+			})
+			return nil
+		}
+
+		fmt.Printf("Approved: %s/%s\n", slug, artType)
+		return nil
+	},
+}
+
+var artifactRejectCmd = &cobra.Command{
+	Use:   "reject <feature> <type>",
+	Short: "Reject an artifact",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, artTypeStr := args[0], args[1]
+		artType := sdlc.ArtifactType(artTypeStr)
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		art := f.GetArtifact(artType)
+		if art == nil {
+			return sdlc.ErrArtifactNotFound
+		}
+
+		art.Reject("user")
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{
+				"feature":  slug,
+				"artifact": string(artType),
+				"status":   "rejected",
+			})
+			return nil
+		}
+
+		fmt.Printf("Rejected: %s/%s\n", slug, artType)
+		return nil
+	},
+}
+
+var artifactStatusCmd = &cobra.Command{
+	Use:   "status <feature>",
+	Short: "Show all artifact statuses for a feature",
+	Args:  cobra.ExactArgs(1),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+
+		f, err := sdlc.LoadFeature(root, args[0])
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(f.Artifacts)
+			return nil
+		}
+
+		fmt.Printf("Artifacts for %s:\n", f.Slug)
+		for _, at := range sdlc.ValidArtifactTypes {
+			art := f.GetArtifact(at)
+			if art == nil {
+				fmt.Printf("  %-12s -\n", at)
+				continue
+			}
+			fmt.Printf("  %-12s %s\n", at, art.Status)
+		}
+		return nil
+	},
+}
+
+func init() {
+	artifactCmd.AddCommand(
+		artifactCreateCmd,
+		artifactApproveCmd,
+		artifactRejectCmd,
+		artifactStatusCmd,
+	)
+	rootCmd.AddCommand(artifactCmd)
+}
diff --git a/cmd/sdlc/cmd_config.go b/cmd/sdlc/cmd_config.go
new file mode 100644
index 0000000..c8eaa75
--- /dev/null
+++ b/cmd/sdlc/cmd_config.go
@@ -0,0 +1,104 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var configCmd = &cobra.Command{
+	Use:   "config",
+	Short: "Manage SDLC configuration",
+}
+
+var configShowCmd = &cobra.Command{
+	Use:   "show",
+	Short: "Show current configuration",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		cfg, err := sdlc.LoadConfig(root)
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(cfg)
+			return nil
+		}
+
+		fmt.Printf("SDLC Config (v%d)\n", cfg.Version)
+		fmt.Printf("  Project: %s\n", cfg.Project.Name)
+		if cfg.Project.Type != "" {
+			fmt.Printf("  Type:    %s\n", cfg.Project.Type)
+		}
+		fmt.Printf("  Main:    %s\n", cfg.Branches.Main)
+		fmt.Printf("  Prefix:  %s\n", cfg.Branches.FeaturePrefix)
+		fmt.Println()
+
+		fmt.Println("Enabled Phases:")
+		for _, p := range cfg.Phases.Enabled {
+			fmt.Printf("  - %s\n", p)
+		}
+		fmt.Println()
+
+		fmt.Println("Compliance:")
+		fmt.Printf("  Require Approvals: %v\n", cfg.Compliance.RequireApprovals)
+		fmt.Printf("  Require Branch:    %v\n", cfg.Compliance.RequireBranch)
+		fmt.Printf("  Require QA:        %v\n", cfg.Compliance.RequireQA)
+
+		return nil
+	},
+}
+
+var configSetCmd = &cobra.Command{
+	Use:   "set <key> <value>",
+	Short: "Set a configuration value",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+
+		cfg, err := sdlc.LoadConfig(root)
+		if err != nil {
+			return err
+		}
+
+		key, value := args[0], args[1]
+		switch key {
+		case "project.name":
+			cfg.Project.Name = value
+		case "project.type":
+			cfg.Project.Type = value
+		case "branches.main":
+			cfg.Branches.Main = value
+		case "branches.feature_prefix":
+			cfg.Branches.FeaturePrefix = value
+		case "compliance.require_approvals":
+			cfg.Compliance.RequireApprovals = value == "true"
+		case "compliance.require_branch":
+			cfg.Compliance.RequireBranch = value == "true"
+		case "compliance.require_qa":
+			cfg.Compliance.RequireQA = value == "true"
+		default:
+			return fmt.Errorf("unknown config key: %s", key)
+		}
+
+		if err := cfg.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"key": key, "value": value, "status": "set"})
+			return nil
+		}
+
+		fmt.Printf("Set %s = %s\n", key, value)
+		return nil
+	},
+}
+
+func init() {
+	configCmd.AddCommand(configShowCmd, configSetCmd)
+	rootCmd.AddCommand(configCmd)
+}
diff --git a/cmd/sdlc/cmd_feature.go b/cmd/sdlc/cmd_feature.go
new file mode 100644
index 0000000..e1b8e8c
--- /dev/null
+++ b/cmd/sdlc/cmd_feature.go
@@ -0,0 +1,321 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var featureTitle string
+
+var featureCmd = &cobra.Command{
+	Use:   "feature",
+	Short: "Manage features",
+}
+
+var featureCreateCmd = &cobra.Command{
+	Use:   "create <slug>",
+	Short: "Create a new feature",
+	Args:  cobra.ExactArgs(1),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug := args[0]
+
+		title := featureTitle
+		if title == "" {
+			title = slug
+		}
+
+		f, err := sdlc.CreateFeature(root, slug, title)
+		if err != nil {
+			return err
+		}
+
+		// Add to active work in state
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+		state.AddActiveFeature(slug, sdlc.PhaseDraft)
+		state.RecordAction("CREATE_FEATURE", slug, "cli")
+		if err := state.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(f)
+			return nil
+		}
+
+		fmt.Printf("Created feature: %s\n", slug)
+		fmt.Printf("  Title: %s\n", f.Title)
+		fmt.Printf("  Phase: %s\n", f.Phase)
+		fmt.Printf("  Path:  .sdlc/features/%s/\n", slug)
+		fmt.Println()
+		fmt.Printf("Next: sdlc next --for %s\n", slug)
+		return nil
+	},
+}
+
+var featureListCmd = &cobra.Command{
+	Use:   "list",
+	Short: "List all features",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		features, err := sdlc.ListFeatures(root)
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(features)
+			return nil
+		}
+
+		if len(features) == 0 {
+			fmt.Println("No features found.")
+			fmt.Println("Create one: sdlc feature create <slug> --title \"Feature Name\"")
+			return nil
+		}
+
+		fmt.Println("Features:")
+		for _, f := range features {
+			summary := sdlc.SummarizeTasks(f.Tasks)
+			taskInfo := ""
+			if summary.Total > 0 {
+				taskInfo = fmt.Sprintf(" (%d/%d tasks)", summary.Completed, summary.Total)
+			}
+			blocked := ""
+			if f.IsBlocked() {
+				blocked = " [BLOCKED]"
+			}
+			fmt.Printf("  %-20s [%-15s]%s%s\n", f.Slug, f.Phase, taskInfo, blocked)
+		}
+		return nil
+	},
+}
+
+var featureShowCmd = &cobra.Command{
+	Use:   "show <slug>",
+	Short: "Show feature details",
+	Args:  cobra.ExactArgs(1),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+
+		f, err := sdlc.LoadFeature(root, args[0])
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(f)
+			return nil
+		}
+
+		fmt.Printf("Feature: %s\n", f.Slug)
+		fmt.Printf("  Title:   %s\n", f.Title)
+		fmt.Printf("  Phase:   %s\n", f.Phase)
+		fmt.Printf("  Created: %s\n", f.Created.Format("2006-01-02 15:04:05"))
+		if f.Branch != "" {
+			fmt.Printf("  Branch:  %s\n", f.Branch)
+		}
+		fmt.Println()
+
+		fmt.Println("Artifacts:")
+		for _, at := range sdlc.ValidArtifactTypes {
+			art := f.GetArtifact(at)
+			if art == nil {
+				continue
+			}
+			fmt.Printf("  %-12s %s\n", at, art.Status)
+		}
+		fmt.Println()
+
+		if len(f.Tasks) > 0 {
+			summary := sdlc.SummarizeTasks(f.Tasks)
+			fmt.Printf("Tasks: %d/%d complete", summary.Completed, summary.Total)
+			if summary.InProgress > 0 {
+				fmt.Printf(", %d in-progress", summary.InProgress)
+			}
+			if summary.Blocked > 0 {
+				fmt.Printf(", %d blocked", summary.Blocked)
+			}
+			fmt.Println()
+		}
+
+		if f.IsBlocked() {
+			fmt.Println()
+			fmt.Println("Blockers:")
+			for _, b := range f.Blockers {
+				fmt.Printf("  - %s\n", b)
+			}
+		}
+
+		return nil
+	},
+}
+
+var featureStatusCmd = &cobra.Command{
+	Use:   "status <slug>",
+	Short: "Show feature phase and progress",
+	Args:  cobra.ExactArgs(1),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+
+		f, err := sdlc.LoadFeature(root, args[0])
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			result := map[string]any{
+				"slug":     f.Slug,
+				"phase":    f.Phase,
+				"blocked":  f.IsBlocked(),
+				"tasks":    sdlc.SummarizeTasks(f.Tasks),
+				"blockers": f.Blockers,
+			}
+			printJSON(result)
+			return nil
+		}
+
+		fmt.Printf("Feature: %s\n", f.Slug)
+		fmt.Printf("Phase:   %s\n", f.Phase)
+		if f.IsBlocked() {
+			fmt.Println("Status:  BLOCKED")
+		}
+
+		if len(f.Tasks) > 0 {
+			s := sdlc.SummarizeTasks(f.Tasks)
+			fmt.Printf("Tasks:   %d/%d complete\n", s.Completed, s.Total)
+		}
+		return nil
+	},
+}
+
+var featureTransitionCmd = &cobra.Command{
+	Use:   "transition <slug> <phase>",
+	Short: "Manually transition feature to a phase",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, phase := args[0], sdlc.FeaturePhase(args[1])
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		cfg, err := sdlc.LoadConfig(root)
+		if err != nil {
+			return err
+		}
+
+		if err := f.CanTransitionTo(phase, cfg); err != nil {
+			return err
+		}
+
+		from := f.Phase
+		if err := f.Transition(phase); err != nil {
+			return err
+		}
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		// Update state
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+		state.UpdateActiveFeature(slug, phase, f.Branch)
+		state.RecordAction("TRANSITION", slug, "cli")
+		if err := state.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{
+				"slug": slug,
+				"from": string(from),
+				"to":   string(phase),
+			})
+			return nil
+		}
+
+		fmt.Printf("Transitioned %s: %s -> %s\n", slug, from, phase)
+		return nil
+	},
+}
+
+var featureBlockCmd = &cobra.Command{
+	Use:   "block <slug> <reason>",
+	Short: "Mark feature as blocked",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, reason := args[0], args[1]
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		f.AddBlocker(reason)
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"slug": slug, "blocker": reason})
+			return nil
+		}
+
+		fmt.Printf("Blocked %s: %s\n", slug, reason)
+		return nil
+	},
+}
+
+var featureUnblockCmd = &cobra.Command{
+	Use:   "unblock <slug>",
+	Short: "Remove all blockers from feature",
+	Args:  cobra.ExactArgs(1),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug := args[0]
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		f.ClearBlockers()
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"slug": slug, "status": "unblocked"})
+			return nil
+		}
+
+		fmt.Printf("Unblocked %s\n", slug)
+		return nil
+	},
+}
+
+func init() {
+	featureCreateCmd.Flags().StringVar(&featureTitle, "title", "", "feature title")
+	featureCmd.AddCommand(
+		featureCreateCmd,
+		featureListCmd,
+		featureShowCmd,
+		featureStatusCmd,
+		featureTransitionCmd,
+		featureBlockCmd,
+		featureUnblockCmd,
+	)
+	rootCmd.AddCommand(featureCmd)
+}
diff --git a/cmd/sdlc/cmd_init.go b/cmd/sdlc/cmd_init.go
new file mode 100644
index 0000000..d922a09
--- /dev/null
+++ b/cmd/sdlc/cmd_init.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var initProjectName string
+
+var initCmd = &cobra.Command{
+	Use:   "init",
+	Short: "Initialize .sdlc/ directory structure",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		name := initProjectName
+		if name == "" {
+			name = filepath.Base(root)
+		}
+
+		if err := sdlc.Init(root, name); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{
+				"status":  "initialized",
+				"root":    root,
+				"project": name,
+			})
+			return nil
+		}
+
+		fmt.Println("Initialized .sdlc/ structure")
+		fmt.Printf("  Root:    %s\n", root)
+		fmt.Printf("  Project: %s\n", name)
+		fmt.Println()
+		fmt.Println("Created directories:")
+		for _, dir := range sdlc.SubDirs() {
+			fmt.Printf("  .sdlc/%s/\n", dir)
+		}
+		fmt.Println()
+		fmt.Println("Next: sdlc feature create <slug> --title \"Feature Name\"")
+		return nil
+	},
+}
+
+func init() {
+	initCmd.Flags().StringVar(&initProjectName, "name", "", "project name (default: directory name)")
+	rootCmd.AddCommand(initCmd)
+}
diff --git a/cmd/sdlc/cmd_next.go b/cmd/sdlc/cmd_next.go
new file mode 100644
index 0000000..07580b3
--- /dev/null
+++ b/cmd/sdlc/cmd_next.go
@@ -0,0 +1,137 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var (
+	nextForFeature string
+)
+
+var nextCmd = &cobra.Command{
+	Use:   "next",
+	Short: "Run classifier and show next required action",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+
+		cfg, err := sdlc.LoadConfig(root)
+		if err != nil {
+			return err
+		}
+
+		classifier := sdlc.NewClassifier()
+
+		// If a specific feature is requested
+		if nextForFeature != "" {
+			return classifyFeature(root, state, cfg, classifier, nextForFeature)
+		}
+
+		// Classify all active features, return first actionable
+		if len(state.ActiveWork.Features) == 0 {
+			if jsonOutput {
+				printJSON(map[string]string{"action": "IDLE", "message": "No active features"})
+				return nil
+			}
+			fmt.Println("No active features. Create one: sdlc feature create <slug>")
+			return nil
+		}
+
+		for _, af := range state.ActiveWork.Features {
+			f, err := sdlc.LoadFeature(root, af.Slug)
+			if err != nil {
+				continue
+			}
+
+			cl := classifier.Classify(&sdlc.EvalContext{
+				State:   state,
+				Feature: f,
+				Config:  cfg,
+				Root:    root,
+			})
+
+			if cl.Action != sdlc.ActionIdle {
+				return printClassification(cl, f)
+			}
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"action": "IDLE", "message": "No actionable work found"})
+			return nil
+		}
+
+		fmt.Println("No actionable work found across active features.")
+		return nil
+	},
+}
+
+func classifyFeature(root string, state *sdlc.State, cfg *sdlc.Config, classifier *sdlc.Classifier, slug string) error {
+	f, err := sdlc.LoadFeature(root, slug)
+	if err != nil {
+		return err
+	}
+
+	cl := classifier.Classify(&sdlc.EvalContext{
+		State:   state,
+		Feature: f,
+		Config:  cfg,
+		Root:    root,
+	})
+
+	return printClassification(cl, f)
+}
+
+func printClassification(cl *sdlc.Classification, f *sdlc.Feature) error {
+	if jsonOutput {
+		printJSON(cl)
+		return nil
+	}
+
+	fmt.Printf("Feature: %s\n", cl.Feature)
+	fmt.Printf("Phase:   %s\n", cl.CurrentPhase)
+
+	if len(f.Tasks) > 0 {
+		s := sdlc.SummarizeTasks(f.Tasks)
+		fmt.Printf("Tasks:   %d/%d complete", s.Completed, s.Total)
+		if s.InProgress > 0 {
+			fmt.Printf(", %d in-progress", s.InProgress)
+		}
+		if s.Pending > 0 {
+			fmt.Printf(", %d pending", s.Pending)
+		}
+		fmt.Println()
+	}
+	fmt.Println()
+
+	fmt.Printf("NEXT ACTION: %s\n", cl.Action)
+	if cl.Message != "" {
+		fmt.Printf("Message:     %s\n", cl.Message)
+	}
+	if cl.NextCommand != "" {
+		fmt.Printf("Command:     %s\n", cl.NextCommand)
+	}
+	if cl.OutputPath != "" {
+		fmt.Printf("Output:      %s\n", cl.OutputPath)
+	}
+	if cl.TransitionTo != "" {
+		fmt.Printf("Transition:  -> %s\n", cl.TransitionTo)
+	}
+	if cl.TaskID != "" {
+		fmt.Printf("Task:        %s\n", cl.TaskID)
+	}
+	fmt.Printf("Rule:        %s\n", cl.RuleMatched)
+
+	return nil
+}
+
+func init() {
+	nextCmd.Flags().StringVar(&nextForFeature, "for", "", "classify specific feature")
+	rootCmd.AddCommand(nextCmd)
+}
diff --git a/cmd/sdlc/cmd_query.go b/cmd/sdlc/cmd_query.go
new file mode 100644
index 0000000..f5bda7d
--- /dev/null
+++ b/cmd/sdlc/cmd_query.go
@@ -0,0 +1,202 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var queryCmd = &cobra.Command{
+	Use:   "query",
+	Short: "Query SDLC state",
+}
+
+var queryBlockedCmd = &cobra.Command{
+	Use:   "blocked",
+	Short: "List all blocked items",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		features, err := sdlc.ListFeatures(root)
+		if err != nil {
+			return err
+		}
+
+		type blockedInfo struct {
+			Slug     string   `json:"slug"`
+			Phase    string   `json:"phase"`
+			Blockers []string `json:"blockers"`
+		}
+
+		var blocked []blockedInfo
+		for _, f := range features {
+			if f.IsBlocked() {
+				blocked = append(blocked, blockedInfo{
+					Slug:     f.Slug,
+					Phase:    string(f.Phase),
+					Blockers: f.Blockers,
+				})
+			}
+		}
+
+		if jsonOutput {
+			printJSON(blocked)
+			return nil
+		}
+
+		if len(blocked) == 0 {
+			fmt.Println("No blocked items.")
+			return nil
+		}
+
+		fmt.Println("Blocked Items:")
+		for _, b := range blocked {
+			fmt.Printf("  %s [%s]:\n", b.Slug, b.Phase)
+			for _, reason := range b.Blockers {
+				fmt.Printf("    - %s\n", reason)
+			}
+		}
+		return nil
+	},
+}
+
+var queryReadyCmd = &cobra.Command{
+	Use:   "ready",
+	Short: "List items ready for work",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+
+		cfg, err := sdlc.LoadConfig(root)
+		if err != nil {
+			return err
+		}
+
+		features, err := sdlc.ListFeatures(root)
+		if err != nil {
+			return err
+		}
+
+		classifier := sdlc.NewClassifier()
+
+		type readyInfo struct {
+			Slug   string `json:"slug"`
+			Phase  string `json:"phase"`
+			Action string `json:"action"`
+		}
+
+		var ready []readyInfo
+		for _, f := range features {
+			if f.IsBlocked() {
+				continue
+			}
+			cl := classifier.Classify(&sdlc.EvalContext{
+				State:   state,
+				Feature: f,
+				Config:  cfg,
+				Root:    root,
+			})
+			if cl.Action != sdlc.ActionIdle && cl.Action != sdlc.ActionBlocked && cl.Action != sdlc.ActionAwaitApproval {
+				ready = append(ready, readyInfo{
+					Slug:   f.Slug,
+					Phase:  string(f.Phase),
+					Action: string(cl.Action),
+				})
+			}
+		}
+
+		if jsonOutput {
+			printJSON(ready)
+			return nil
+		}
+
+		if len(ready) == 0 {
+			fmt.Println("No items ready for work.")
+			return nil
+		}
+
+		fmt.Println("Ready for Work:")
+		for _, r := range ready {
+			fmt.Printf("  %-20s [%-15s] -> %s\n", r.Slug, r.Phase, r.Action)
+		}
+		return nil
+	},
+}
+
+var queryNeedsApprovalCmd = &cobra.Command{
+	Use:   "needs-approval",
+	Short: "List items awaiting approval",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+
+		cfg, err := sdlc.LoadConfig(root)
+		if err != nil {
+			return err
+		}
+
+		features, err := sdlc.ListFeatures(root)
+		if err != nil {
+			return err
+		}
+
+		classifier := sdlc.NewClassifier()
+
+		type approvalInfo struct {
+			Slug    string `json:"slug"`
+			Phase   string `json:"phase"`
+			Message string `json:"message"`
+		}
+
+		var pending []approvalInfo
+		for _, f := range features {
+			cl := classifier.Classify(&sdlc.EvalContext{
+				State:   state,
+				Feature: f,
+				Config:  cfg,
+				Root:    root,
+			})
+			if cl.Action == sdlc.ActionAwaitApproval {
+				pending = append(pending, approvalInfo{
+					Slug:    f.Slug,
+					Phase:   string(f.Phase),
+					Message: cl.Message,
+				})
+			}
+		}
+
+		if jsonOutput {
+			printJSON(pending)
+			return nil
+		}
+
+		if len(pending) == 0 {
+			fmt.Println("No items awaiting approval.")
+			return nil
+		}
+
+		fmt.Println("Awaiting Approval:")
+		for _, p := range pending {
+			fmt.Printf("  %-20s [%-15s] %s\n", p.Slug, p.Phase, p.Message)
+		}
+		return nil
+	},
+}
+
+func init() {
+	queryCmd.AddCommand(
+		queryBlockedCmd,
+		queryReadyCmd,
+		queryNeedsApprovalCmd,
+	)
+	rootCmd.AddCommand(queryCmd)
+}
diff --git a/cmd/sdlc/cmd_state.go b/cmd/sdlc/cmd_state.go
new file mode 100644
index 0000000..d5c1380
--- /dev/null
+++ b/cmd/sdlc/cmd_state.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var stateCmd = &cobra.Command{
+	Use:   "state",
+	Short: "Show current SDLC state",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		root := mustResolveRoot()
+
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(state)
+			return nil
+		}
+
+		fmt.Printf("SDLC State (v%d)\n", state.Version)
+		fmt.Printf("  Project: %s\n", state.Project.Name)
+		if state.Project.CurrentRoadmap != "" {
+			fmt.Printf("  Roadmap: %s\n", state.Project.CurrentRoadmap)
+		}
+		fmt.Println()
+
+		if len(state.ActiveWork.Features) > 0 {
+			fmt.Println("Active Features:")
+			for _, f := range state.ActiveWork.Features {
+				branch := ""
+				if f.Branch != "" {
+					branch = fmt.Sprintf(" (%s)", f.Branch)
+				}
+				fmt.Printf("  - %s [%s]%s\n", f.Slug, f.Phase, branch)
+			}
+			fmt.Println()
+		}
+
+		if len(state.Blocked) > 0 {
+			fmt.Println("Blocked Items:")
+			for _, b := range state.Blocked {
+				fmt.Printf("  - %s/%s: %s\n", b.Type, b.Slug, b.Reason)
+			}
+			fmt.Println()
+		}
+
+		if state.LastAction != "" {
+			fmt.Printf("Last Action: %s by %s\n", state.LastAction, state.LastActor)
+		}
+		if state.LastUpdated != nil {
+			fmt.Printf("Last Updated: %s\n", state.LastUpdated.Format("2006-01-02 15:04:05"))
+		}
+
+		return nil
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(stateCmd)
+}
diff --git a/cmd/sdlc/cmd_task.go b/cmd/sdlc/cmd_task.go
new file mode 100644
index 0000000..0553348
--- /dev/null
+++ b/cmd/sdlc/cmd_task.go
@@ -0,0 +1,207 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var taskCmd = &cobra.Command{
+	Use:   "task",
+	Short: "Manage feature tasks",
+}
+
+var taskListCmd = &cobra.Command{
+	Use:   "list <feature>",
+	Short: "List tasks for a feature",
+	Args:  cobra.ExactArgs(1),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+
+		f, err := sdlc.LoadFeature(root, args[0])
+		if err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(f.Tasks)
+			return nil
+		}
+
+		if len(f.Tasks) == 0 {
+			fmt.Println("No tasks defined.")
+			fmt.Printf("Add one: sdlc task add %s \"Task title\"\n", args[0])
+			return nil
+		}
+
+		summary := sdlc.SummarizeTasks(f.Tasks)
+		fmt.Printf("Tasks for %s (%d/%d complete):\n", f.Slug, summary.Completed, summary.Total)
+		for _, t := range f.Tasks {
+			icon := "○"
+			switch t.Status {
+			case sdlc.TaskComplete:
+				icon = "✓"
+			case sdlc.TaskInProgress:
+				icon = "→"
+			case sdlc.TaskBlocked:
+				icon = "✗"
+			}
+			fmt.Printf("  %s %s: %s [%s]\n", icon, t.ID, t.Title, t.Status)
+		}
+		return nil
+	},
+}
+
+var taskStartCmd = &cobra.Command{
+	Use:   "start <feature> <task-id>",
+	Short: "Mark a task as in-progress",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, taskID := args[0], args[1]
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		f.Tasks, err = sdlc.StartTask(f.Tasks, taskID)
+		if err != nil {
+			return err
+		}
+		f.UpdateTaskSummary()
+
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"feature": slug, "task": taskID, "status": "in_progress"})
+			return nil
+		}
+
+		fmt.Printf("Started: %s/%s\n", slug, taskID)
+		return nil
+	},
+}
+
+var taskCompleteCmd = &cobra.Command{
+	Use:   "complete <feature> <task-id>",
+	Short: "Mark a task as complete",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, taskID := args[0], args[1]
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		f.Tasks, err = sdlc.CompleteTask(f.Tasks, taskID)
+		if err != nil {
+			return err
+		}
+		f.UpdateTaskSummary()
+
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		// Record in state
+		state, err := sdlc.LoadState(root)
+		if err != nil {
+			return err
+		}
+		state.RecordAction("COMPLETE_TASK", slug, "cli")
+		if err := state.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"feature": slug, "task": taskID, "status": "complete"})
+			return nil
+		}
+
+		s := sdlc.SummarizeTasks(f.Tasks)
+		fmt.Printf("Completed: %s/%s (%d/%d tasks done)\n", slug, taskID, s.Completed, s.Total)
+		return nil
+	},
+}
+
+var taskBlockCmd = &cobra.Command{
+	Use:   "block <feature> <task-id>",
+	Short: "Mark a task as blocked",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, taskID := args[0], args[1]
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		f.Tasks, err = sdlc.BlockTask(f.Tasks, taskID)
+		if err != nil {
+			return err
+		}
+		f.UpdateTaskSummary()
+
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		if jsonOutput {
+			printJSON(map[string]string{"feature": slug, "task": taskID, "status": "blocked"})
+			return nil
+		}
+
+		fmt.Printf("Blocked: %s/%s\n", slug, taskID)
+		return nil
+	},
+}
+
+var taskAddCmd = &cobra.Command{
+	Use:   "add <feature> <title>",
+	Short: "Add a new task",
+	Args:  cobra.ExactArgs(2),
+	RunE: func(_ *cobra.Command, args []string) error {
+		root := mustResolveRoot()
+		slug, title := args[0], args[1]
+
+		f, err := sdlc.LoadFeature(root, slug)
+		if err != nil {
+			return err
+		}
+
+		f.Tasks = sdlc.AddTask(f.Tasks, title)
+		f.UpdateTaskSummary()
+
+		if err := f.Save(root); err != nil {
+			return err
+		}
+
+		newTask := f.Tasks[len(f.Tasks)-1]
+
+		if jsonOutput {
+			printJSON(newTask)
+			return nil
+		}
+
+		fmt.Printf("Added: %s/%s - %s\n", slug, newTask.ID, title)
+		return nil
+	},
+}
+
+func init() {
+	taskCmd.AddCommand(
+		taskListCmd,
+		taskStartCmd,
+		taskCompleteCmd,
+		taskBlockCmd,
+		taskAddCmd,
+	)
+	rootCmd.AddCommand(taskCmd)
+}
diff --git a/cmd/sdlc/main.go b/cmd/sdlc/main.go
new file mode 100644
index 0000000..a5a50d9
--- /dev/null
+++ b/cmd/sdlc/main.go
@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
diff --git a/cmd/sdlc/root.go b/cmd/sdlc/root.go
new file mode 100644
index 0000000..a8ccc9b
--- /dev/null
+++ b/cmd/sdlc/root.go
@@ -0,0 +1,81 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/spf13/cobra"
+)
+
+var (
+	rootDir    string
+	jsonOutput bool
+)
+
+var rootCmd = &cobra.Command{
+	Use:   "sdlc",
+	Short: "Deterministic SDLC orchestration tool",
+	Long:  "Manage the software development lifecycle with deterministic state, artifacts, and classification.",
+}
+
+func init() {
+	rootCmd.PersistentFlags().StringVar(&rootDir, "root", "", "project root (default: auto-detect)")
+	rootCmd.PersistentFlags().BoolVar(&jsonOutput, "json", false, "output as JSON")
+}
+
+// resolveRoot finds the project root by looking for .sdlc/ or .git/ walking up.
+func resolveRoot() (string, error) {
+	if rootDir != "" {
+		abs, err := filepath.Abs(rootDir)
+		if err != nil {
+			return "", fmt.Errorf("resolve root: %w", err)
+		}
+		return abs, nil
+	}
+
+	dir, err := os.Getwd()
+	if err != nil {
+		return "", fmt.Errorf("get working directory: %w", err)
+	}
+
+	for {
+		if sdlc.IsInitialized(dir) {
+			return dir, nil
+		}
+		if _, err := os.Stat(filepath.Join(dir, ".git")); err == nil {
+			return dir, nil
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			break
+		}
+		dir = parent
+	}
+
+	// Fall back to cwd
+	cwd, _ := os.Getwd()
+	return cwd, nil
+}
+
+// mustResolveRoot resolves root or exits.
+func mustResolveRoot() string {
+	root, err := resolveRoot()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+	return root
+}
+
+// printJSON marshals v as indented JSON and prints to stdout.
+func printJSON(v any) {
+	data, err := json.MarshalIndent(v, "", "  ")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error marshaling JSON: %v\n", err)
+		os.Exit(1)
+	}
+	fmt.Println(string(data))
+}
diff --git a/cookbooks/VISION.md b/cookbooks/VISION.md
index c943f20..1628244 100644
--- a/cookbooks/VISION.md
+++ b/cookbooks/VISION.md
@@ -257,6 +257,24 @@ POST /project/landing/build
 
 ---
 
+## Cookbooks
+
+| Cookbook | Status | Description |
+|---------|--------|-------------|
+| [Landing Page](./landing-page.md) | Done | Simple single-component deployment |
+| [Feature Development](./feature-development.md) | Done | Full-stack feature with chassis, OpenAPI, auth, design system |
+
+## E2E Test Scripts
+
+| Script | Description |
+|--------|-------------|
+| `scripts/landing-test.sh` | Landing page E2E test |
+| `scripts/feature-test.sh` | Feature development E2E test |
+| `scripts/composable-test.sh` | Composable monorepo E2E test |
+| `scripts/template-validation.sh` | Template validation checks |
+
+---
+
 ## Questions to Resolve
 
 1. **Claudebox scaling strategy?**
diff --git a/cookbooks/feature-development.md b/cookbooks/feature-development.md
index ea4a6a5..90971e6 100644
--- a/cookbooks/feature-development.md
+++ b/cookbooks/feature-development.md
@@ -764,6 +764,66 @@ Check that `AuthProvider` wraps your app in `providers.tsx`.
 
 ---
 
+## Chassis Framework
+
+The `pkg/chassis` package provides a convenience facade over `pkg/app`:
+
+```go
+import "my-project/pkg/chassis"
+
+svc := chassis.New("my-service", chassis.WithDefaultPort(8080))
+```
+
+It re-exports: `New`, `Wrap`, `WrapWithLogger`, `Bind`, `BindAndValidate`, `BindStrict`, `NewHealthHandler`, `PingChecker`, `HTTPChecker`.
+
+## OpenAPI Documentation
+
+Each service defines its spec in `internal/api/spec.go`:
+
+```go
+spec := openapi.NewOpenAPISpec("My API", "1.0.0").
+    WithBearerSecurity("bearer", "JWT token")
+
+spec.WithSchema("User", openapi.Object(map[string]openapi.Schema{
+    "id":    openapi.UUID(),
+    "email": openapi.Email(),
+}, "id", "email"))
+
+spec.AddPath("/api/v1/users/{id}", "get", map[string]any{
+    "summary":    "Get user",
+    "tags":       []string{"Users"},
+    "parameters": []any{openapi.IDParam()},
+    "responses": map[string]any{
+        "200": openapi.OpResponse("Success", openapi.ResponseSchema(openapi.Ref("User"))),
+        "404": openapi.OpResponse("Not found", openapi.ErrorResponseSchema()),
+    },
+})
+
+application.EnableDocs(spec) // Mounts /docs (Scalar UI) and /openapi.json
+```
+
+## Design System Components
+
+Available from `@project/ui`:
+
+| Component | Usage |
+|-----------|-------|
+| Button | Primary actions, variants: default, destructive, outline, ghost |
+| Card | Content containers with CardHeader, CardContent, CardFooter |
+| Input, Label | Form fields |
+| Badge | Status indicators, variants: success, warning, error, info |
+| Dialog | Modal dialogs |
+| Table | Data tables |
+| Select | Dropdowns |
+| Alert | Notification banners, variants: default, destructive, success, warning |
+| Textarea | Multiline input |
+| DropdownMenu | Context menus with items, checkboxes, radio groups |
+| Sheet | Slide-in panels (side: top, right, bottom, left) |
+
+All use CSS custom properties: `var(--background)`, `var(--accent)`, `var(--border)`, etc.
+
+---
+
 ## Related
 
 - [Composable App Cookbook](./composable-app.md) - Creating projects with components
diff --git a/cookbooks/scripts/feature-test.sh b/cookbooks/scripts/feature-test.sh
index 32e0116..d87ffb6 100755
--- a/cookbooks/scripts/feature-test.sh
+++ b/cookbooks/scripts/feature-test.sh
@@ -97,6 +97,30 @@ verify_chassis_patterns() {
     else
         print_warning "pkg/auth/ not found"
     fi
+
+    # Check pkg/chassis exists
+    echo "Checking pkg/chassis..."
+    local chassis_check
+    chassis_check=$(curl -s "https://git.threesix.ai/api/v1/repos/$git_owner/$project_id/contents/pkg/chassis/chassis.go" \
+        -H "Authorization: token ${GITEA_TOKEN:-}" 2>/dev/null | jq -r '.name // "not found"')
+
+    if [[ "$chassis_check" == "chassis.go" ]]; then
+        print_success "pkg/chassis/chassis.go exists (facade)"
+    else
+        print_warning "pkg/chassis/chassis.go not found"
+    fi
+
+    # Check pkg/openapi exists
+    echo "Checking pkg/openapi..."
+    local openapi_check
+    openapi_check=$(curl -s "https://git.threesix.ai/api/v1/repos/$git_owner/$project_id/contents/pkg/openapi" \
+        -H "Authorization: token ${GITEA_TOKEN:-}" 2>/dev/null | jq -r 'if type == "array" then "directory" else "not found" end')
+
+    if [[ "$openapi_check" == "directory" ]]; then
+        print_success "pkg/openapi/ directory exists (spec builder + docs)"
+    else
+        print_warning "pkg/openapi/ not found"
+    fi
 }
 
 # Verify design system packages
@@ -187,6 +211,30 @@ verify_service_patterns() {
     else
         print_warning "routes.go not found"
     fi
+
+    # Check services/api/internal/api/spec.go exists (OpenAPI)
+    echo "Checking spec.go (OpenAPI)..."
+    local spec_check
+    spec_check=$(curl -s "https://git.threesix.ai/api/v1/repos/$git_owner/$project_id/contents/services/api/internal/api/spec.go" \
+        -H "Authorization: token ${GITEA_TOKEN:-}" 2>/dev/null | jq -r '.name // "not found"')
+
+    if [[ "$spec_check" == "spec.go" ]]; then
+        print_success "services/api/internal/api/spec.go exists (OpenAPI spec)"
+    else
+        print_warning "spec.go not found"
+    fi
+
+    # Check services/api/internal/api/handlers/example_test.go exists
+    echo "Checking example_test.go..."
+    local test_check
+    test_check=$(curl -s "https://git.threesix.ai/api/v1/repos/$git_owner/$project_id/contents/services/api/internal/api/handlers/example_test.go" \
+        -H "Authorization: token ${GITEA_TOKEN:-}" 2>/dev/null | jq -r '.name // "not found"')
+
+    if [[ "$test_check" == "example_test.go" ]]; then
+        print_success "services/api/internal/api/handlers/example_test.go exists"
+    else
+        print_warning "example_test.go not found"
+    fi
 }
 
 # Verify app-nextjs component
diff --git a/go.mod b/go.mod
index a683346..b9fb0a0 100644
--- a/go.mod
+++ b/go.mod
@@ -11,12 +11,14 @@ require (
 	github.com/lib/pq v1.10.9
 	github.com/prometheus/client_golang v1.23.2
 	github.com/redis/go-redis/v9 v9.17.3
+	github.com/spf13/cobra v1.10.2
 	github.com/stretchr/testify v1.11.1
 	go.opentelemetry.io/otel v1.39.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.39.0
 	go.opentelemetry.io/otel/sdk v1.39.0
 	go.opentelemetry.io/otel/trace v1.39.0
 	go.woodpecker-ci.org/woodpecker/v3 v3.13.0
+	gopkg.in/yaml.v3 v3.0.1
 	k8s.io/api v0.35.0
 	k8s.io/apimachinery v0.35.0
 	k8s.io/client-go v0.35.0
@@ -41,6 +43,7 @@ require (
 	github.com/google/gnostic-models v0.7.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.3 // indirect
 	github.com/hashicorp/go-version v1.7.0 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
@@ -72,7 +75,6 @@ require (
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/evanphx/json-patch.v4 v4.13.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/klog/v2 v2.130.1 // indirect
 	k8s.io/kube-openapi v0.0.0-20250910181357-589584f1c912 // indirect
 	k8s.io/utils v0.0.0-20251002143259-bc988d571ff4 // indirect
diff --git a/go.sum b/go.sum
index 9a5b63b..8682cb4 100644
--- a/go.sum
+++ b/go.sum
@@ -16,6 +16,7 @@ github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1x
 github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
@@ -62,6 +63,8 @@ github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.3 h1:NmZ1PKzSTQbuGHw9DGPFomqkkLW
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.3/go.mod h1:zQrxl1YP88HQlA6i9c63DSVPFklWpGX4OWAc9bFuaH4=
 github.com/hashicorp/go-version v1.7.0 h1:5tqGy27NaOTB8yJKUZELlFAS/LTKJkrmONwQKeRZfjY=
 github.com/hashicorp/go-version v1.7.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
@@ -106,6 +109,9 @@ github.com/redis/go-redis/v9 v9.17.3 h1:fN29NdNrE17KttK5Ndf20buqfDZwGNgoUr9qjl1D
 github.com/redis/go-redis/v9 v9.17.3/go.mod h1:u410H11HMLoB+TP67dz8rL9s6QW2j76l0//kSOd3370=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
+github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
 github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
 github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
diff --git a/internal/adapter/kubernetes/sdlc_executor.go b/internal/adapter/kubernetes/sdlc_executor.go
new file mode 100644
index 0000000..e09125c
--- /dev/null
+++ b/internal/adapter/kubernetes/sdlc_executor.go
@@ -0,0 +1,288 @@
+package kubernetes
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"os/exec"
+	"strings"
+
+	"github.com/orchard9/rdev/internal/port"
+	"github.com/orchard9/rdev/internal/sdlc"
+)
+
+// SDLCExecutor runs sdlc CLI commands inside pods via kubectl exec.
+type SDLCExecutor struct {
+	namespace string
+	logger    *slog.Logger
+}
+
+// SDLCExecutorConfig configures the SDLC executor.
+type SDLCExecutorConfig struct {
+	Namespace string
+	Logger    *slog.Logger
+}
+
+// NewSDLCExecutor creates a new SDLC executor.
+func NewSDLCExecutor(cfg SDLCExecutorConfig) *SDLCExecutor {
+	logger := cfg.Logger
+	if logger == nil {
+		logger = slog.Default()
+	}
+	return &SDLCExecutor{
+		namespace: cfg.Namespace,
+		logger:    logger.With("component", "sdlc-executor"),
+	}
+}
+
+// execSDLC runs a sdlc CLI command in the pod and returns stdout bytes.
+// All commands include --json for machine-readable output.
+func (e *SDLCExecutor) execSDLC(ctx context.Context, podName string, args ...string) ([]byte, error) {
+	kubectlArgs := []string{"exec", "-n", e.namespace, podName, "--", "sdlc"}
+	kubectlArgs = append(kubectlArgs, args...)
+	kubectlArgs = append(kubectlArgs, "--json")
+
+	cmd := exec.CommandContext(ctx, "kubectl", kubectlArgs...)
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		return nil, e.mapExecError(stderr.String(), err)
+	}
+	return stdout.Bytes(), nil
+}
+
+// execSDLCNoOutput runs a sdlc CLI command that produces no meaningful stdout.
+func (e *SDLCExecutor) execSDLCNoOutput(ctx context.Context, podName string, args ...string) error {
+	_, err := e.execSDLC(ctx, podName, args...)
+	return err
+}
+
+// mapExecError maps stderr text from the sdlc CLI to sentinel errors.
+func (e *SDLCExecutor) mapExecError(stderr string, execErr error) error {
+	stderr = strings.TrimSpace(stderr)
+
+	switch {
+	case strings.Contains(stderr, "sdlc not initialized"):
+		return sdlc.ErrNotInitialized
+	case strings.Contains(stderr, "feature not found"):
+		return sdlc.ErrFeatureNotFound
+	case strings.Contains(stderr, "feature already exists"):
+		return sdlc.ErrFeatureExists
+	case strings.Contains(stderr, "invalid phase transition"):
+		return sdlc.ErrInvalidTransition
+	case strings.Contains(stderr, "invalid phase"):
+		return sdlc.ErrInvalidPhase
+	case strings.Contains(stderr, "task not found"):
+		return sdlc.ErrTaskNotFound
+	case strings.Contains(stderr, "artifact not found"):
+		return sdlc.ErrArtifactNotFound
+	case strings.Contains(stderr, "invalid slug"):
+		return sdlc.ErrInvalidSlug
+	case strings.Contains(stderr, "invalid artifact"):
+		return sdlc.ErrInvalidArtifact
+	default:
+		if stderr != "" {
+			return fmt.Errorf("sdlc exec: %s: %w", stderr, execErr)
+		}
+		return fmt.Errorf("sdlc exec: %w", execErr)
+	}
+}
+
+// GetState returns the global SDLC state for a project pod.
+func (e *SDLCExecutor) GetState(ctx context.Context, podName string) (*sdlc.State, error) {
+	out, err := e.execSDLC(ctx, podName, "state")
+	if err != nil {
+		return nil, err
+	}
+	var state sdlc.State
+	if err := json.Unmarshal(out, &state); err != nil {
+		return nil, fmt.Errorf("parse sdlc state: %w", err)
+	}
+	return &state, nil
+}
+
+// GetNext returns the classifier's recommendation for the next action.
+func (e *SDLCExecutor) GetNext(ctx context.Context, podName, feature string) (*sdlc.Classification, error) {
+	args := []string{"next"}
+	if feature != "" {
+		args = append(args, "--feature", feature)
+	}
+	out, err := e.execSDLC(ctx, podName, args...)
+	if err != nil {
+		return nil, err
+	}
+	var cl sdlc.Classification
+	if err := json.Unmarshal(out, &cl); err != nil {
+		return nil, fmt.Errorf("parse sdlc classification: %w", err)
+	}
+	return &cl, nil
+}
+
+// ListFeatures returns all features in the project.
+func (e *SDLCExecutor) ListFeatures(ctx context.Context, podName string) ([]*sdlc.Feature, error) {
+	out, err := e.execSDLC(ctx, podName, "feature", "list")
+	if err != nil {
+		return nil, err
+	}
+	var features []*sdlc.Feature
+	if err := json.Unmarshal(out, &features); err != nil {
+		return nil, fmt.Errorf("parse sdlc features: %w", err)
+	}
+	return features, nil
+}
+
+// GetFeature returns a single feature by slug.
+func (e *SDLCExecutor) GetFeature(ctx context.Context, podName, slug string) (*sdlc.Feature, error) {
+	out, err := e.execSDLC(ctx, podName, "feature", "show", slug)
+	if err != nil {
+		return nil, err
+	}
+	var f sdlc.Feature
+	if err := json.Unmarshal(out, &f); err != nil {
+		return nil, fmt.Errorf("parse sdlc feature: %w", err)
+	}
+	return &f, nil
+}
+
+// CreateFeature creates a new feature with the given slug and title.
+func (e *SDLCExecutor) CreateFeature(ctx context.Context, podName, slug, title string) (*sdlc.Feature, error) {
+	out, err := e.execSDLC(ctx, podName, "feature", "create", slug, "--title", title)
+	if err != nil {
+		return nil, err
+	}
+	var f sdlc.Feature
+	if err := json.Unmarshal(out, &f); err != nil {
+		return nil, fmt.Errorf("parse sdlc feature: %w", err)
+	}
+	return &f, nil
+}
+
+// TransitionFeature moves a feature to the specified phase.
+func (e *SDLCExecutor) TransitionFeature(ctx context.Context, podName, slug string, phase sdlc.FeaturePhase) error {
+	return e.execSDLCNoOutput(ctx, podName, "feature", "transition", slug, string(phase))
+}
+
+// BlockFeature adds a blocker reason to a feature.
+func (e *SDLCExecutor) BlockFeature(ctx context.Context, podName, slug, reason string) error {
+	return e.execSDLCNoOutput(ctx, podName, "feature", "block", slug, "--reason", reason)
+}
+
+// UnblockFeature removes all blockers from a feature.
+func (e *SDLCExecutor) UnblockFeature(ctx context.Context, podName, slug string) error {
+	return e.execSDLCNoOutput(ctx, podName, "feature", "unblock", slug)
+}
+
+// DeleteFeature removes a feature entirely.
+func (e *SDLCExecutor) DeleteFeature(ctx context.Context, podName, slug string) error {
+	return e.execSDLCNoOutput(ctx, podName, "feature", "delete", slug, "--force")
+}
+
+// GetArtifactStatus returns artifact statuses for a feature.
+func (e *SDLCExecutor) GetArtifactStatus(ctx context.Context, podName, slug string) (map[sdlc.ArtifactType]*sdlc.Artifact, error) {
+	out, err := e.execSDLC(ctx, podName, "artifact", "status", slug)
+	if err != nil {
+		return nil, err
+	}
+	var artifacts map[sdlc.ArtifactType]*sdlc.Artifact
+	if err := json.Unmarshal(out, &artifacts); err != nil {
+		return nil, fmt.Errorf("parse sdlc artifacts: %w", err)
+	}
+	return artifacts, nil
+}
+
+// ApproveArtifact approves a feature artifact.
+func (e *SDLCExecutor) ApproveArtifact(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error {
+	return e.execSDLCNoOutput(ctx, podName, "artifact", "approve", slug, string(artType))
+}
+
+// RejectArtifact rejects a feature artifact.
+func (e *SDLCExecutor) RejectArtifact(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error {
+	return e.execSDLCNoOutput(ctx, podName, "artifact", "reject", slug, string(artType))
+}
+
+// ListTasks returns all tasks for a feature.
+func (e *SDLCExecutor) ListTasks(ctx context.Context, podName, slug string) ([]sdlc.Task, error) {
+	out, err := e.execSDLC(ctx, podName, "task", "list", slug)
+	if err != nil {
+		return nil, err
+	}
+	var tasks []sdlc.Task
+	if err := json.Unmarshal(out, &tasks); err != nil {
+		return nil, fmt.Errorf("parse sdlc tasks: %w", err)
+	}
+	return tasks, nil
+}
+
+// AddTask adds a new task to a feature.
+func (e *SDLCExecutor) AddTask(ctx context.Context, podName, slug, title string) (*sdlc.Task, error) {
+	out, err := e.execSDLC(ctx, podName, "task", "add", slug, "--title", title)
+	if err != nil {
+		return nil, err
+	}
+	var t sdlc.Task
+	if err := json.Unmarshal(out, &t); err != nil {
+		return nil, fmt.Errorf("parse sdlc task: %w", err)
+	}
+	return &t, nil
+}
+
+// StartTask marks a task as in-progress.
+func (e *SDLCExecutor) StartTask(ctx context.Context, podName, slug, taskID string) error {
+	return e.execSDLCNoOutput(ctx, podName, "task", "start", slug, taskID)
+}
+
+// CompleteTask marks a task as complete.
+func (e *SDLCExecutor) CompleteTask(ctx context.Context, podName, slug, taskID string) error {
+	return e.execSDLCNoOutput(ctx, podName, "task", "complete", slug, taskID)
+}
+
+// BlockTask marks a task as blocked.
+func (e *SDLCExecutor) BlockTask(ctx context.Context, podName, slug, taskID string) error {
+	return e.execSDLCNoOutput(ctx, podName, "task", "block", slug, taskID)
+}
+
+// QueryBlocked returns all blocked features.
+func (e *SDLCExecutor) QueryBlocked(ctx context.Context, podName string) ([]port.BlockedInfo, error) {
+	out, err := e.execSDLC(ctx, podName, "query", "blocked")
+	if err != nil {
+		return nil, err
+	}
+	var blocked []port.BlockedInfo
+	if err := json.Unmarshal(out, &blocked); err != nil {
+		return nil, fmt.Errorf("parse sdlc blocked query: %w", err)
+	}
+	return blocked, nil
+}
+
+// QueryReady returns features ready for work.
+func (e *SDLCExecutor) QueryReady(ctx context.Context, podName string) ([]port.ReadyInfo, error) {
+	out, err := e.execSDLC(ctx, podName, "query", "ready")
+	if err != nil {
+		return nil, err
+	}
+	var ready []port.ReadyInfo
+	if err := json.Unmarshal(out, &ready); err != nil {
+		return nil, fmt.Errorf("parse sdlc ready query: %w", err)
+	}
+	return ready, nil
+}
+
+// QueryNeedsApproval returns features awaiting approval.
+func (e *SDLCExecutor) QueryNeedsApproval(ctx context.Context, podName string) ([]port.ApprovalInfo, error) {
+	out, err := e.execSDLC(ctx, podName, "query", "needs-approval")
+	if err != nil {
+		return nil, err
+	}
+	var pending []port.ApprovalInfo
+	if err := json.Unmarshal(out, &pending); err != nil {
+		return nil, fmt.Errorf("parse sdlc approval query: %w", err)
+	}
+	return pending, nil
+}
+
+// Compile-time interface check.
+var _ port.SDLCExecutor = (*SDLCExecutor)(nil)
diff --git a/internal/adapter/kubernetes/sdlc_executor_test.go b/internal/adapter/kubernetes/sdlc_executor_test.go
new file mode 100644
index 0000000..105a92f
--- /dev/null
+++ b/internal/adapter/kubernetes/sdlc_executor_test.go
@@ -0,0 +1,114 @@
+package kubernetes
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+)
+
+func TestMapExecError(t *testing.T) {
+	exec := &SDLCExecutor{namespace: "test"}
+	baseErr := errors.New("exit status 1")
+
+	tests := []struct {
+		name    string
+		stderr  string
+		want    error
+		wantMsg string
+	}{
+		{
+			name:   "not initialized",
+			stderr: "Error: sdlc not initialized: run 'sdlc init'",
+			want:   sdlc.ErrNotInitialized,
+		},
+		{
+			name:   "feature not found",
+			stderr: "Error: feature not found",
+			want:   sdlc.ErrFeatureNotFound,
+		},
+		{
+			name:   "feature already exists",
+			stderr: "Error: feature already exists",
+			want:   sdlc.ErrFeatureExists,
+		},
+		{
+			name:   "invalid phase transition",
+			stderr: "Error: invalid phase transition: cannot move from draft to implementation (backward)",
+			want:   sdlc.ErrInvalidTransition,
+		},
+		{
+			name:   "invalid phase",
+			stderr: "Error: invalid phase: xyz",
+			want:   sdlc.ErrInvalidPhase,
+		},
+		{
+			name:   "task not found",
+			stderr: "Error: task not found",
+			want:   sdlc.ErrTaskNotFound,
+		},
+		{
+			name:   "artifact not found",
+			stderr: "Error: artifact not found",
+			want:   sdlc.ErrArtifactNotFound,
+		},
+		{
+			name:   "invalid slug",
+			stderr: "Error: invalid slug: must be lowercase alphanumeric with hyphens",
+			want:   sdlc.ErrInvalidSlug,
+		},
+		{
+			name:   "invalid artifact type",
+			stderr: "Error: invalid artifact type: foobar",
+			want:   sdlc.ErrInvalidArtifact,
+		},
+		{
+			name:    "unknown error with stderr",
+			stderr:  "something unexpected happened",
+			wantMsg: "sdlc exec: something unexpected happened: exit status 1",
+		},
+		{
+			name:    "unknown error without stderr",
+			stderr:  "",
+			wantMsg: "sdlc exec: exit status 1",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := exec.mapExecError(tt.stderr, baseErr)
+			if tt.want != nil {
+				if !errors.Is(got, tt.want) {
+					t.Errorf("mapExecError() = %v, want %v", got, tt.want)
+				}
+			} else if tt.wantMsg != "" {
+				if got.Error() != tt.wantMsg {
+					t.Errorf("mapExecError() message = %q, want %q", got.Error(), tt.wantMsg)
+				}
+			}
+		})
+	}
+}
+
+func TestMapExecError_WhitespaceHandling(t *testing.T) {
+	exec := &SDLCExecutor{namespace: "test"}
+	baseErr := errors.New("exit status 1")
+
+	// Stderr with leading/trailing whitespace
+	got := exec.mapExecError("  feature not found\n  ", baseErr)
+	if !errors.Is(got, sdlc.ErrFeatureNotFound) {
+		t.Errorf("expected ErrFeatureNotFound, got %v", got)
+	}
+}
+
+func TestNewSDLCExecutor(t *testing.T) {
+	exec := NewSDLCExecutor(SDLCExecutorConfig{
+		Namespace: "rdev",
+	})
+	if exec.namespace != "rdev" {
+		t.Errorf("namespace = %q, want %q", exec.namespace, "rdev")
+	}
+	if exec.logger == nil {
+		t.Error("logger should not be nil")
+	}
+}
diff --git a/internal/adapter/templates/templates/components/service/.env.example.tmpl b/internal/adapter/templates/templates/components/service/.env.example.tmpl
index 5a631b0..f01de5f 100644
--- a/internal/adapter/templates/templates/components/service/.env.example.tmpl
+++ b/internal/adapter/templates/templates/components/service/.env.example.tmpl
@@ -13,5 +13,9 @@ APP_DEBUG=true
 LOG_LEVEL=debug
 LOG_FORMAT=text
 
+# Auth (set AUTH_ENABLED=true to require JWT for protected routes)
+AUTH_ENABLED=false
+JWT_SECRET=dev-secret-change-in-production
+
 # Database (if needed)
 DATABASE_URL=postgres://dev:dev@localhost:5432/{{PROJECT_NAME}}?sslmode=disable
diff --git a/internal/adapter/templates/templates/components/service/internal/api/handlers/example.go.tmpl b/internal/adapter/templates/templates/components/service/internal/api/handlers/example.go.tmpl
index 98afbce..38104f7 100644
--- a/internal/adapter/templates/templates/components/service/internal/api/handlers/example.go.tmpl
+++ b/internal/adapter/templates/templates/components/service/internal/api/handlers/example.go.tmpl
@@ -3,6 +3,9 @@ package handlers
 import (
 	"net/http"
 
+	"github.com/go-chi/chi/v5"
+	"github.com/google/uuid"
+
 	"{{GO_MODULE}}/pkg/app"
 	"{{GO_MODULE}}/pkg/httperror"
 	"{{GO_MODULE}}/pkg/httpresponse"
@@ -25,34 +28,82 @@ type CreateRequest struct {
 	Description string `json:"description" validate:"max=500"`
 }
 
-// CreateResponse is the response for creating an example.
-type CreateResponse struct {
+// UpdateRequest is the request body for updating an example.
+type UpdateRequest struct {
+	Name        string `json:"name" validate:"omitempty,min=1,max=100"`
+	Description string `json:"description" validate:"max=500"`
+}
+
+// ExampleResponse is the response for an example resource.
+type ExampleResponse struct {
 	ID          string `json:"id"`
 	Name        string `json:"name"`
 	Description string `json:"description"`
+	CreatedAt   string `json:"created_at"`
+	UpdatedAt   string `json:"updated_at"`
+}
+
+// List returns a paginated list of examples.
+// Demonstrates pagination query params and list responses.
+func (h *Example) List(w http.ResponseWriter, r *http.Request) error {
+	// Example: Parse pagination query params
+	// page := r.URL.Query().Get("page")
+	// perPage := r.URL.Query().Get("per_page")
+
+	// Example: Fetch from database
+	// items, total, err := h.repo.List(r.Context(), page, perPage)
+	// if err != nil {
+	//     return err
+	// }
+
+	// Placeholder response
+	items := []ExampleResponse{
+		{
+			ID:          "550e8400-e29b-41d4-a716-446655440000",
+			Name:        "Example Item 1",
+			Description: "First example item",
+			CreatedAt:   "2024-01-15T10:30:00Z",
+			UpdatedAt:   "2024-01-15T10:30:00Z",
+		},
+		{
+			ID:          "550e8400-e29b-41d4-a716-446655440001",
+			Name:        "Example Item 2",
+			Description: "Second example item",
+			CreatedAt:   "2024-01-16T12:00:00Z",
+			UpdatedAt:   "2024-01-16T12:00:00Z",
+		},
+	}
+
+	httpresponse.OK(w, r, items)
+	return nil
 }
 
 // Get returns an example by ID.
 // Demonstrates returning HTTPErrors for common error cases.
 func (h *Example) Get(w http.ResponseWriter, r *http.Request) error {
-	// Get ID from path parameter (using chi)
-	// id := chi.URLParam(r, "id")
+	id := chi.URLParam(r, "id")
 
-	// Example: resource not found
-	// if item == nil {
-	//     return httperror.NotFoundf("example %s not found", id)
+	// Validate UUID format
+	if _, err := uuid.Parse(id); err != nil {
+		return httperror.BadRequest("invalid id format")
+	}
+
+	// Example: Fetch from database
+	// item, err := h.repo.Get(r.Context(), id)
+	// if err != nil {
+	//     if errors.Is(err, ErrNotFound) {
+	//         return httperror.NotFoundf("example %s not found", id)
+	//     }
+	//     return err
 	// }
 
-	// Example: forbidden access
-	// if !canAccess(user, item) {
-	//     return httperror.Forbidden("access denied")
-	// }
-
-	// Success response
-	httpresponse.OK(w, r, map[string]any{
-		"id":          "example-123",
-		"name":        "Example Item",
-		"description": "This is an example item",
+	// Placeholder response
+	httpresponse.OK(w, r, ExampleResponse{
+		ID:          id,
+		Name:        "Example Item",
+		Description: "This is an example item",
+		CreatedAt:   "2024-01-15T10:30:00Z",
+		UpdatedAt:   "2024-01-15T10:30:00Z",
 	})
 	return nil
 }
@@ -63,27 +114,90 @@ func (h *Example) Create(w http.ResponseWriter, r *http.Request) error {
 	var req CreateRequest
 
 	// Bind and validate request body
-	// Returns HTTPError on failure, which Wrap will handle
 	if err := app.BindAndValidate(r, &req); err != nil {
 		return err
 	}
 
-	// Example: business logic error
-	// if exists(req.Name) {
+	// Example: Check for duplicates
+	// if exists, _ := h.repo.GetByName(r.Context(), req.Name); exists != nil {
 	//     return httperror.Conflict("example with this name already exists")
 	// }
 
-	// Example: internal error (will be logged, generic message returned to client)
-	// if err := db.Create(item); err != nil {
-	//     h.logger.Error("failed to create example", "error", err)
-	//     return err // Generic errors become 500 Internal Error
+	// Example: Create in database
+	// item, err := h.repo.Create(r.Context(), req)
+	// if err != nil {
+	//     return err
 	// }
 
-	// Success response
-	httpresponse.Created(w, r, CreateResponse{
-		ID:          "example-456",
+	// Example: Access authenticated user
+	// user := auth.GetUser(r.Context())
+	// h.logger.Info("example created", "by", user.ID, "name", req.Name)
+
+	id := uuid.New().String()
+
+	httpresponse.Created(w, r, ExampleResponse{
+		ID:          id,
 		Name:        req.Name,
 		Description: req.Description,
+		CreatedAt:   "2024-01-15T10:30:00Z",
+		UpdatedAt:   "2024-01-15T10:30:00Z",
 	})
 	return nil
 }
+
+// Update updates an existing example.
+// Demonstrates partial updates with BindAndValidate.
+func (h *Example) Update(w http.ResponseWriter, r *http.Request) error {
+	id := chi.URLParam(r, "id")
+
+	if _, err := uuid.Parse(id); err != nil {
+		return httperror.BadRequest("invalid id format")
+	}
+
+	var req UpdateRequest
+	if err := app.BindAndValidate(r, &req); err != nil {
+		return err
+	}
+
+	// Example: Fetch existing, apply updates, save
+	// item, err := h.repo.Get(r.Context(), id)
+	// if err != nil {
+	//     if errors.Is(err, ErrNotFound) {
+	//         return httperror.NotFoundf("example %s not found", id)
+	//     }
+	//     return err
+	// }
+	// if err := h.repo.Update(r.Context(), id, req); err != nil {
+	//     return err
+	// }
+
+	httpresponse.OK(w, r, ExampleResponse{
+		ID:          id,
+		Name:        req.Name,
+		Description: req.Description,
+		CreatedAt:   "2024-01-15T10:30:00Z",
+		UpdatedAt:   "2024-01-16T14:00:00Z",
+	})
+	return nil
+}
+
+// Delete deletes an example by ID.
+// Demonstrates no-content response.
+func (h *Example) Delete(w http.ResponseWriter, r *http.Request) error {
+	id := chi.URLParam(r, "id")
+
+	if _, err := uuid.Parse(id); err != nil {
+		return httperror.BadRequest("invalid id format")
+	}
+
+	// Example: Delete from database
+	// if err := h.repo.Delete(r.Context(), id); err != nil {
+	//     if errors.Is(err, ErrNotFound) {
+	//         return httperror.NotFoundf("example %s not found", id)
+	//     }
+	//     return err
+	// }
+
+	httpresponse.NoContent(w)
+	return nil
+}
diff --git a/internal/adapter/templates/templates/components/service/internal/api/handlers/example_test.go.tmpl b/internal/adapter/templates/templates/components/service/internal/api/handlers/example_test.go.tmpl
new file mode 100644
index 0000000..03a76e7
--- /dev/null
+++ b/internal/adapter/templates/templates/components/service/internal/api/handlers/example_test.go.tmpl
@@ -0,0 +1,183 @@
+package handlers
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+
+	"{{GO_MODULE}}/pkg/logging"
+)
+
+func newTestLogger() *logging.Logger {
+	return logging.New(logging.Config{
+		Level:  logging.LevelDebug,
+		Format: logging.FormatText,
+	})
+}
+
+func TestExample_List(t *testing.T) {
+	handler := NewExample(newTestLogger())
+
+	r := chi.NewRouter()
+	r.Get("/api/v1/examples", func(w http.ResponseWriter, r *http.Request) {
+		if err := handler.List(w, r); err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/examples", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d", w.Code)
+	}
+
+	var resp map[string]any
+	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+
+	data, ok := resp["data"]
+	if !ok {
+		t.Fatal("expected 'data' field in response")
+	}
+
+	items, ok := data.([]any)
+	if !ok {
+		t.Fatal("expected 'data' to be an array")
+	}
+
+	if len(items) == 0 {
+		t.Error("expected at least one item in response")
+	}
+}
+
+func TestExample_Get(t *testing.T) {
+	handler := NewExample(newTestLogger())
+
+	tests := []struct {
+		name       string
+		id         string
+		wantStatus int
+	}{
+		{
+			name:       "valid uuid",
+			id:         "550e8400-e29b-41d4-a716-446655440000",
+			wantStatus: http.StatusOK,
+		},
+		{
+			name:       "invalid uuid",
+			id:         "not-a-uuid",
+			wantStatus: http.StatusBadRequest,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := chi.NewRouter()
+			r.Get("/api/v1/examples/{id}", func(w http.ResponseWriter, r *http.Request) {
+				if err := handler.Get(w, r); err != nil {
+					// Error-returning handler: convert error to status
+					w.WriteHeader(http.StatusBadRequest)
+					return
+				}
+			})
+
+			req := httptest.NewRequest(http.MethodGet, "/api/v1/examples/"+tt.id, nil)
+			w := httptest.NewRecorder()
+			r.ServeHTTP(w, req)
+
+			if w.Code != tt.wantStatus {
+				t.Errorf("expected status %d, got %d", tt.wantStatus, w.Code)
+			}
+		})
+	}
+}
+
+func TestExample_Create(t *testing.T) {
+	handler := NewExample(newTestLogger())
+
+	tests := []struct {
+		name       string
+		body       any
+		wantStatus int
+	}{
+		{
+			name: "valid request",
+			body: CreateRequest{
+				Name:        "Test Example",
+				Description: "A test description",
+			},
+			wantStatus: http.StatusCreated,
+		},
+		{
+			name:       "empty body",
+			body:       nil,
+			wantStatus: http.StatusBadRequest,
+		},
+		{
+			name: "missing required name",
+			body: map[string]string{
+				"description": "no name provided",
+			},
+			wantStatus: http.StatusUnprocessableEntity,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := chi.NewRouter()
+			r.Post("/api/v1/examples", func(w http.ResponseWriter, r *http.Request) {
+				if err := handler.Create(w, r); err != nil {
+					// Simulate Wrap behavior for tests
+					w.WriteHeader(http.StatusBadRequest)
+					return
+				}
+			})
+
+			var body []byte
+			if tt.body != nil {
+				var err error
+				body, err = json.Marshal(tt.body)
+				if err != nil {
+					t.Fatalf("failed to marshal body: %v", err)
+				}
+			}
+
+			req := httptest.NewRequest(http.MethodPost, "/api/v1/examples", bytes.NewReader(body))
+			req.Header.Set("Content-Type", "application/json")
+			w := httptest.NewRecorder()
+			r.ServeHTTP(w, req)
+
+			// For the valid case, check 201
+			if tt.name == "valid request" && w.Code != http.StatusCreated {
+				t.Errorf("expected status %d, got %d", http.StatusCreated, w.Code)
+			}
+		})
+	}
+}
+
+func TestExample_Delete(t *testing.T) {
+	handler := NewExample(newTestLogger())
+
+	r := chi.NewRouter()
+	r.Delete("/api/v1/examples/{id}", func(w http.ResponseWriter, r *http.Request) {
+		if err := handler.Delete(w, r); err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+	})
+
+	req := httptest.NewRequest(http.MethodDelete, "/api/v1/examples/550e8400-e29b-41d4-a716-446655440000", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNoContent {
+		t.Errorf("expected status 204, got %d", w.Code)
+	}
+}
diff --git a/internal/adapter/templates/templates/components/service/internal/api/routes.go.tmpl b/internal/adapter/templates/templates/components/service/internal/api/routes.go.tmpl
index c0c5f92..ee3dae7 100644
--- a/internal/adapter/templates/templates/components/service/internal/api/routes.go.tmpl
+++ b/internal/adapter/templates/templates/components/service/internal/api/routes.go.tmpl
@@ -3,23 +3,46 @@ package api
 
 import (
 	"{{GO_MODULE}}/pkg/app"
+	"{{GO_MODULE}}/pkg/auth"
 	"{{GO_MODULE}}/services/{{COMPONENT_NAME}}/internal/api/handlers"
+	"{{GO_MODULE}}/services/{{COMPONENT_NAME}}/internal/config"
 )
 
 // RegisterRoutes registers all HTTP routes for the service.
 func RegisterRoutes(application *app.App) {
 	logger := application.Logger()
+	cfg := config.Load()
 
 	// Initialize handlers
 	healthHandler := handlers.NewHealth(logger)
 	exampleHandler := handlers.NewExample(logger)
 
+	// Build and mount OpenAPI spec
+	spec := NewServiceSpec()
+	application.EnableDocs(spec)
+
 	// Register API routes
 	application.Route("/api/v1", func(r app.Router) {
 		r.Get("/health", healthHandler.Check)
 
-		// Example routes using Wrap pattern for error-returning handlers
-		r.Get("/example", app.Wrap(exampleHandler.Get))
-		r.Post("/example", app.Wrap(exampleHandler.Create))
+		// Public routes (no auth required)
+		r.Get("/examples", app.Wrap(exampleHandler.List))
+		r.Get("/examples/{id}", app.Wrap(exampleHandler.Get))
+
+		// Protected routes (auth required when enabled)
+		r.Group(func(r app.Router) {
+			if cfg.AuthEnabled {
+				r.Use(auth.Middleware(auth.MiddlewareConfig{
+					Validator: auth.NewJWTValidator(auth.JWTConfig{
+						Secret: []byte(cfg.JWTSecret),
+						Issuer: "{{PROJECT_NAME}}",
+					}),
+				}))
+			}
+
+			r.Post("/examples", app.Wrap(exampleHandler.Create))
+			r.Put("/examples/{id}", app.Wrap(exampleHandler.Update))
+			r.Delete("/examples/{id}", app.Wrap(exampleHandler.Delete))
+		})
 	})
 }
diff --git a/internal/adapter/templates/templates/components/service/internal/api/spec.go.tmpl b/internal/adapter/templates/templates/components/service/internal/api/spec.go.tmpl
new file mode 100644
index 0000000..4ef3351
--- /dev/null
+++ b/internal/adapter/templates/templates/components/service/internal/api/spec.go.tmpl
@@ -0,0 +1,112 @@
+package api
+
+import "{{GO_MODULE}}/pkg/openapi"
+
+// NewServiceSpec builds the OpenAPI specification for the {{COMPONENT_NAME}} service.
+func NewServiceSpec() *openapi.OpenAPISpec {
+	spec := openapi.NewOpenAPISpec("{{COMPONENT_NAME}} API", "1.0.0").
+		WithDescription("REST API for the {{COMPONENT_NAME}} service").
+		WithBearerSecurity("bearer", "JWT authentication token").
+		WithTag("Health", "Service health endpoints").
+		WithTag("Examples", "Example CRUD endpoints")
+
+	// Define reusable schemas
+	spec.WithSchema("Example", openapi.Object(map[string]openapi.Schema{
+		"id":          openapi.UUID().WithDescription("Unique identifier"),
+		"name":        openapi.String().WithDescription("Name of the example").WithExample("My Example"),
+		"description": openapi.String().WithDescription("Optional description").WithExample("A description"),
+		"created_at":  openapi.DateTime().WithDescription("Creation timestamp"),
+		"updated_at":  openapi.DateTime().WithDescription("Last update timestamp"),
+	}, "id", "name"))
+
+	spec.WithSchema("CreateExampleRequest", openapi.Object(map[string]openapi.Schema{
+		"name":        openapi.StringWithMinMax(1, 100).WithDescription("Name of the example"),
+		"description": openapi.StringWithMinMax(0, 500).WithDescription("Optional description"),
+	}, "name"))
+
+	spec.WithSchema("UpdateExampleRequest", openapi.Object(map[string]openapi.Schema{
+		"name":        openapi.StringWithMinMax(1, 100).WithDescription("Updated name"),
+		"description": openapi.StringWithMinMax(0, 500).WithDescription("Updated description"),
+	}))
+
+	// Health
+	spec.AddPath("/api/v1/health", "get", map[string]any{
+		"summary": "Health check",
+		"tags":    []string{"Health"},
+		"responses": map[string]any{
+			"200": openapi.OpResponse("Service is healthy", openapi.Object(map[string]openapi.Schema{
+				"service": openapi.String(),
+				"status":  openapi.String(),
+			})),
+		},
+	})
+
+	// List examples
+	spec.AddPath("/api/v1/examples", "get", map[string]any{
+		"summary":     "List examples",
+		"description": "Returns a paginated list of examples.",
+		"tags":        []string{"Examples"},
+		"parameters":  []any{openapi.PageParam(), openapi.PerPageParam()},
+		"responses": map[string]any{
+			"200": openapi.OpResponse("Success", openapi.ResponseSchema(openapi.RefArray("Example"))),
+		},
+	})
+
+	// Get example
+	spec.AddPath("/api/v1/examples/{id}", "get", map[string]any{
+		"summary":    "Get example by ID",
+		"tags":       []string{"Examples"},
+		"parameters": []any{openapi.IDParam()},
+		"responses": map[string]any{
+			"200": openapi.OpResponse("Success", openapi.ResponseSchema(openapi.Ref("Example"))),
+			"404": openapi.OpResponse("Not found", openapi.ErrorResponseSchema()),
+		},
+	})
+
+	// Create example
+	spec.AddPath("/api/v1/examples", "post", map[string]any{
+		"summary":     "Create example",
+		"description": "Creates a new example. Requires authentication.",
+		"tags":        []string{"Examples"},
+		"security":    []map[string][]string{{"bearer": {}}},
+		"requestBody": openapi.RequestBody(openapi.Ref("CreateExampleRequest"), true),
+		"responses": map[string]any{
+			"201": openapi.OpResponse("Created", openapi.ResponseSchema(openapi.Ref("Example"))),
+			"400": openapi.OpResponse("Bad request", openapi.ErrorResponseSchema()),
+			"401": openapi.OpResponse("Unauthorized", openapi.ErrorResponseSchema()),
+			"422": openapi.OpResponse("Validation error", openapi.ErrorResponseSchema()),
+		},
+	})
+
+	// Update example
+	spec.AddPath("/api/v1/examples/{id}", "put", map[string]any{
+		"summary":     "Update example",
+		"description": "Updates an existing example. Requires authentication.",
+		"tags":        []string{"Examples"},
+		"security":    []map[string][]string{{"bearer": {}}},
+		"parameters":  []any{openapi.IDParam()},
+		"requestBody": openapi.RequestBody(openapi.Ref("UpdateExampleRequest"), true),
+		"responses": map[string]any{
+			"200": openapi.OpResponse("Updated", openapi.ResponseSchema(openapi.Ref("Example"))),
+			"400": openapi.OpResponse("Bad request", openapi.ErrorResponseSchema()),
+			"401": openapi.OpResponse("Unauthorized", openapi.ErrorResponseSchema()),
+			"404": openapi.OpResponse("Not found", openapi.ErrorResponseSchema()),
+		},
+	})
+
+	// Delete example
+	spec.AddPath("/api/v1/examples/{id}", "delete", map[string]any{
+		"summary":     "Delete example",
+		"description": "Deletes an example by ID. Requires authentication.",
+		"tags":        []string{"Examples"},
+		"security":    []map[string][]string{{"bearer": {}}},
+		"parameters":  []any{openapi.IDParam()},
+		"responses": map[string]any{
+			"204": openapi.OpResponseNoContent(),
+			"401": openapi.OpResponse("Unauthorized", openapi.ErrorResponseSchema()),
+			"404": openapi.OpResponse("Not found", openapi.ErrorResponseSchema()),
+		},
+	})
+
+	return spec
+}
diff --git a/internal/adapter/templates/templates/components/service/internal/config/config.go.tmpl b/internal/adapter/templates/templates/components/service/internal/config/config.go.tmpl
index 884b9d1..0152c87 100644
--- a/internal/adapter/templates/templates/components/service/internal/config/config.go.tmpl
+++ b/internal/adapter/templates/templates/components/service/internal/config/config.go.tmpl
@@ -2,6 +2,9 @@
 package config
 
 import (
+	"os"
+	"strings"
+
 	"{{GO_MODULE}}/pkg/config"
 )
 
@@ -11,22 +14,21 @@ type Config struct {
 	Server   config.ServerConfig
 	Database config.DatabaseConfig
 	Logging  config.LoggingConfig
-	// Add service-specific config fields here
+
+	// Auth
+	AuthEnabled bool
+	JWTSecret   string
 }
 
 // Load reads configuration from environment variables.
-func Load() (*Config, error) {
-	if err := config.Init(config.Options{
-		AppName:     "{{COMPONENT_NAME}}",
-		DefaultPort: {{PORT}},
-	}); err != nil {
-		return nil, err
-	}
-
+func Load() *Config {
 	return &Config{
 		AppConfig: config.ReadAppConfig(),
 		Server:    config.ReadServerConfig(),
 		Database:  config.ReadDatabaseConfig(),
 		Logging:   config.ReadLoggingConfig(),
-	}, nil
+
+		AuthEnabled: strings.EqualFold(os.Getenv("AUTH_ENABLED"), "true"),
+		JWTSecret:   os.Getenv("JWT_SECRET"),
+	}
 }
diff --git a/internal/adapter/templates/templates/skeleton/.claude/guides/backend/api-patterns.md.tmpl b/internal/adapter/templates/templates/skeleton/.claude/guides/backend/api-patterns.md.tmpl
new file mode 100644
index 0000000..246f7fd
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/.claude/guides/backend/api-patterns.md.tmpl
@@ -0,0 +1,151 @@
+# Backend API Patterns
+
+## Handler Pattern (Wrap)
+
+All handlers return `error` and are wrapped with `app.Wrap()`:
+
+```go
+func (h *Handler) Get(w http.ResponseWriter, r *http.Request) error {
+    id := chi.URLParam(r, "id")
+    item, err := h.svc.Get(r.Context(), id)
+    if err != nil {
+        if errors.Is(err, ErrNotFound) {
+            return httperror.NotFoundf("item %s not found", id)
+        }
+        return err // becomes 500
+    }
+    httpresponse.OK(w, r, item)
+    return nil
+}
+
+// In routes.go:
+r.Get("/items/{id}", app.Wrap(handler.Get))
+```
+
+## Request Binding
+
+Use `app.Bind` or `app.BindAndValidate`:
+
+```go
+func (h *Handler) Create(w http.ResponseWriter, r *http.Request) error {
+    var req CreateRequest
+    if err := app.BindAndValidate(r, &req); err != nil {
+        return err // returns 400 or 422 HTTPError
+    }
+    // req is decoded and validated
+}
+```
+
+Validation uses go-playground/validator struct tags:
+- `validate:"required"` - field is required
+- `validate:"min=1,max=100"` - length constraints
+- `validate:"email"` - email format
+- `validate:"uuid"` - UUID format
+
+## HTTPError Sentinels
+
+Use `httperror` factories to return typed errors:
+
+| Function | Status | When to use |
+|----------|--------|-------------|
+| `httperror.BadRequest(msg)` | 400 | Invalid input format |
+| `httperror.Unauthorized(msg)` | 401 | Missing/invalid credentials |
+| `httperror.Forbidden(msg)` | 403 | No permission |
+| `httperror.NotFoundf(fmt, args)` | 404 | Resource doesn't exist |
+| `httperror.Conflict(msg)` | 409 | Duplicate resource |
+| `httperror.Validation(msg)` | 422 | Struct validation failure |
+| `httperror.Internal(msg)` | 500 | Server error (prefer returning raw err) |
+
+Add details with `httperror.WithDetails(err, details)`.
+
+## Response Envelope
+
+All responses use the standard envelope from `httpresponse`:
+
+```json
+{
+  "data": { ... },
+  "meta": {
+    "request_id": "abc-123",
+    "timestamp": "2024-01-15T10:30:00Z"
+  }
+}
+```
+
+Use `httpresponse.OK(w, r, data)`, `httpresponse.Created(w, r, data)`, `httpresponse.NoContent(w)`.
+
+## OpenAPI Documentation
+
+Annotate endpoints in a `spec.go` file:
+
+```go
+spec := openapi.NewOpenAPISpec("Service Name", "1.0.0").
+    WithBearerSecurity("bearer", "JWT token")
+
+spec.WithSchema("Item", openapi.Object(map[string]openapi.Schema{
+    "id":   openapi.UUID(),
+    "name": openapi.String().WithExample("My Item"),
+}, "id", "name"))
+
+spec.AddPath("/api/v1/items", "get", map[string]any{
+    "summary": "List items",
+    "tags":    []string{"Items"},
+    "responses": map[string]any{
+        "200": openapi.OpResponse("Success", openapi.RefArray("Item")),
+    },
+})
+```
+
+Mount with `application.EnableDocs(spec)` to get `/docs` (Scalar UI) and `/openapi.json`.
+
+## Auth Integration
+
+Auth is opt-in via `AUTH_ENABLED=true`:
+
+```go
+// In routes.go - protected route group
+r.Group(func(r app.Router) {
+    if cfg.AuthEnabled {
+        r.Use(auth.Middleware(auth.MiddlewareConfig{
+            Validator: auth.NewJWTValidator(auth.JWTConfig{
+                Secret: []byte(cfg.JWTSecret),
+            }),
+        }))
+    }
+    r.Post("/items", app.Wrap(handler.Create))
+})
+```
+
+Access user in handlers:
+```go
+user := auth.GetUser(r.Context())
+if user != nil {
+    logger.Info("created by", "user", user.ID)
+}
+```
+
+## Health Checks
+
+Basic health is auto-registered at `/health` and `/ready`.
+
+For dependency checks:
+```go
+healthHandler := app.NewHealthHandler(app.HealthConfig{
+    Service: "my-service",
+    Checks: map[string]app.HealthChecker{
+        "database": app.PingChecker(db.PingContext),
+        "redis":    app.PingChecker(redis.Ping),
+    },
+})
+r.Get("/health", healthHandler)
+```
+
+## Chassis Package
+
+The `pkg/chassis` package re-exports `pkg/app` types for convenience:
+
+```go
+import "{{GO_MODULE}}/pkg/chassis"
+
+svc := chassis.New("my-service", chassis.WithDefaultPort(8080))
+```
diff --git a/internal/adapter/templates/templates/skeleton/.claude/guides/frontend/design-system.md.tmpl b/internal/adapter/templates/templates/skeleton/.claude/guides/frontend/design-system.md.tmpl
new file mode 100644
index 0000000..3c99a6b
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/.claude/guides/frontend/design-system.md.tmpl
@@ -0,0 +1,125 @@
+# Frontend Design System
+
+## UI Components (`@{{PROJECT_NAME}}/ui`)
+
+Available components from `packages/ui`:
+
+| Component | Import | Variants |
+|-----------|--------|----------|
+| Button | `Button` | default, destructive, outline, secondary, ghost, link |
+| Card | `Card, CardHeader, CardTitle, CardDescription, CardContent, CardFooter` | - |
+| Input | `Input` | - |
+| Label | `Label` | - |
+| Badge | `Badge` | default, secondary, outline, success, warning, error, info |
+| Dialog | `Dialog, DialogTrigger, DialogContent, DialogHeader, DialogTitle, DialogDescription, DialogFooter, DialogClose` | - |
+| Table | `Table, TableHeader, TableBody, TableRow, TableHead, TableCell` | - |
+| Select | `Select, SelectTrigger, SelectContent, SelectItem, SelectValue` | - |
+| Checkbox | `Checkbox` | - |
+| Alert | `Alert, AlertTitle, AlertDescription` | default, destructive, success, warning |
+| Textarea | `Textarea` | - |
+| DropdownMenu | `DropdownMenu, DropdownMenuTrigger, DropdownMenuContent, DropdownMenuItem, ...` | - |
+| Sheet | `Sheet, SheetTrigger, SheetContent, SheetHeader, SheetTitle, SheetDescription, SheetFooter` | side: top, right, bottom, left |
+
+Usage:
+```tsx
+import { Button, Badge, Card, CardContent } from '@{{PROJECT_NAME}}/ui';
+
+<Card>
+  <CardContent>
+    <Badge variant="success">Active</Badge>
+    <Button variant="outline">Edit</Button>
+  </CardContent>
+</Card>
+```
+
+## CSS Tokens
+
+All components use CSS custom properties for theming. Define these in your app's globals.css:
+
+### Colors
+- `--background` - Page background
+- `--surface-100` - Card/input backgrounds
+- `--surface-200` - Hover states, secondary surfaces
+- `--text-primary` - Main text
+- `--text-secondary` - Secondary text
+- `--text-muted` - Placeholder, hint text
+- `--accent` - Primary accent color
+- `--accent-foreground` - Text on accent
+- `--border` - Border color
+
+### Semantic Colors
+- `--success`, `--success-bg`, `--success-border` - Success states
+- `--warning`, `--warning-bg`, `--warning-border` - Warning states
+- `--error`, `--error-bg`, `--error-border` - Error states
+- `--info`, `--info-bg`, `--info-border` - Info states
+
+### Z-Index
+- `--z-popover` - Dropdowns, tooltips
+- `--z-modal` - Dialogs, sheets
+
+Import base tokens: `import '@{{PROJECT_NAME}}/ui/styles';`
+
+## Layout (`@{{PROJECT_NAME}}/layout`)
+
+DashboardShell provides the standard app layout:
+
+```tsx
+import { DashboardShell, Sidebar, Header } from '@{{PROJECT_NAME}}/layout';
+
+<DashboardShell
+  sidebar={<Sidebar items={navItems} />}
+  header={<Header title="Dashboard" />}
+>
+  {children}
+</DashboardShell>
+```
+
+## Auth (`@{{PROJECT_NAME}}/auth`)
+
+AuthProvider and ProtectedRoute for client-side auth:
+
+```tsx
+import { AuthProvider, ProtectedRoute, useAuth } from '@{{PROJECT_NAME}}/auth';
+
+// Wrap app in AuthProvider
+<AuthProvider>
+  <App />
+</AuthProvider>
+
+// Protect routes
+<ProtectedRoute>
+  <DashboardPage />
+</ProtectedRoute>
+
+// Access auth state
+const { user, isAuthenticated, login, logout } = useAuth();
+```
+
+## API Client (`@{{PROJECT_NAME}}/api-client`)
+
+Typed API client with auth:
+
+```tsx
+import { createAPIClient } from '@{{PROJECT_NAME}}/api-client';
+
+const api = createAPIClient({
+  baseURL: process.env.NEXT_PUBLIC_API_URL,
+});
+
+// Use in server actions or client components
+const items = await api.examples.list();
+const item = await api.examples.get(id);
+await api.examples.create({ name: 'New Item' });
+```
+
+## Icons
+
+Re-exported from lucide-react via `@{{PROJECT_NAME}}/ui`:
+
+```tsx
+import { Plus, Search, Settings, Trash2, User } from '@{{PROJECT_NAME}}/ui';
+```
+
+## Dark Theme
+
+All components default to dark theme using CSS variables. The design system is dark-first with surface layering (surface-100 lighter than background, surface-200 lighter than surface-100).
diff --git a/internal/adapter/templates/templates/skeleton/CLAUDE.md.tmpl b/internal/adapter/templates/templates/skeleton/CLAUDE.md.tmpl
index 563b2d3..436e09c 100644
--- a/internal/adapter/templates/templates/skeleton/CLAUDE.md.tmpl
+++ b/internal/adapter/templates/templates/skeleton/CLAUDE.md.tmpl
@@ -8,6 +8,8 @@
 |-------------------|-----------|
 | **Set up local dev** | [local/setup.md](.claude/guides/local/setup.md) |
 | **Build a feature** | [feature-development.md](.claude/guides/feature-development.md) |
+| **Backend API patterns** | [backend/api-patterns.md](.claude/guides/backend/api-patterns.md) |
+| **Frontend design system** | [frontend/design-system.md](.claude/guides/frontend/design-system.md) |
 | **Deploy** | [ops/deploying.md](.claude/guides/ops/deploying.md) |
 
 ## Quick Reference
@@ -23,6 +25,17 @@
 ./scripts/discover.sh
 ```
 
+## Critical Rules
+
+- **Handler pattern:** All handlers return `error`, wrapped with `app.Wrap()`. HTTPErrors map to status codes; raw errors become 500.
+- **Request binding:** Always use `app.Bind()` or `app.BindAndValidate()`. Never use raw `json.NewDecoder`.
+- **Error types:** Use `httperror.BadRequest`, `httperror.NotFound`, etc. Never bare `http.Error()`.
+- **Response envelope:** Use `httpresponse.OK`, `httpresponse.Created`, `httpresponse.NoContent`. All responses use `{data, meta}` envelope.
+- **Auth middleware:** Auth is opt-in. Use `auth.Middleware()` in route groups for protected endpoints.
+- **OpenAPI first:** Document endpoints in `spec.go` using `openapi.*` helpers. Mount with `application.EnableDocs(spec)`.
+- **CSS variables:** All UI components use CSS custom properties (`var(--background)`, `var(--accent)`, etc.). Never hardcode colors.
+- **Monorepo imports:** Go packages from `{{GO_MODULE}}/pkg/*`, TypeScript from `@{{PROJECT_NAME}}/*`.
+
 ## Architecture
 
 ```
@@ -31,8 +44,24 @@
 ├── workers/      # Background workers (no port)
 ├── apps/         # Frontend applications (port 3001+)
 ├── cli/          # CLI tools (no port)
-├── packages/     # Shared TypeScript packages (@{{PROJECT_NAME}}/*)
-├── pkg/          # Shared Go packages ({{GO_MODULE}}/pkg/*)
+├── packages/     # Shared TypeScript packages
+│   ├── ui/       # UI components (@{{PROJECT_NAME}}/ui)
+│   ├── layout/   # Dashboard layout (@{{PROJECT_NAME}}/layout)
+│   ├── auth/     # Auth provider (@{{PROJECT_NAME}}/auth)
+│   ├── api-client/ # Typed API client (@{{PROJECT_NAME}}/api-client)
+│   └── logger/   # HTTP/console logger (@{{PROJECT_NAME}}/logger)
+├── pkg/          # Shared Go packages
+│   ├── app/      # Service bootstrapper (Wrap, Bind, Health)
+│   ├── chassis/  # Facade re-exporting app types
+│   ├── openapi/  # OpenAPI 3.0 spec builder + Scalar docs
+│   ├── httperror/ # Typed HTTP errors
+│   ├── httpresponse/ # Response envelope helpers
+│   ├── httpvalidation/ # Struct validation
+│   ├── middleware/ # RequestID, CORS, Recovery, Logger
+│   ├── auth/     # JWT, API key, middleware
+│   ├── config/   # Viper-based configuration
+│   ├── httpclient/ # Resilient HTTP client
+│   └── logging/  # slog wrapper
 └── scripts/      # Development & CI scripts
 ```
 
@@ -40,7 +69,7 @@
 |------|----------|------------|---------|
 | services/ | Go | 8001+ | REST APIs, backend services |
 | workers/ | Go | none | Background jobs, queue consumers |
-| apps/ | TypeScript | 3001+ | React, Astro frontends |
+| apps/ | TypeScript | 3001+ | React, Next.js, Astro frontends |
 | cli/ | Go | none | CLI tools, scripts |
 | packages/ | TypeScript | none | Shared frontend packages |
 | pkg/ | Go | none | Shared backend packages |
diff --git a/internal/adapter/templates/templates/skeleton/packages/ui/package.json.tmpl b/internal/adapter/templates/templates/skeleton/packages/ui/package.json.tmpl
index cef6a54..575d1da 100644
--- a/internal/adapter/templates/templates/skeleton/packages/ui/package.json.tmpl
+++ b/internal/adapter/templates/templates/skeleton/packages/ui/package.json.tmpl
@@ -20,6 +20,7 @@
   "dependencies": {
     "@radix-ui/react-checkbox": "^1.0.4",
     "@radix-ui/react-dialog": "^1.0.5",
+    "@radix-ui/react-dropdown-menu": "^2.0.6",
     "@radix-ui/react-label": "^2.0.2",
     "@radix-ui/react-select": "^2.0.0",
     "@radix-ui/react-slot": "^1.0.2",
diff --git a/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Alert.tsx b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Alert.tsx
new file mode 100644
index 0000000..f3f8349
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Alert.tsx
@@ -0,0 +1,62 @@
+import * as React from 'react';
+import { cva, type VariantProps } from 'class-variance-authority';
+import { cn } from '../utils/cn';
+
+const alertVariants = cva(
+  'relative w-full rounded-lg border p-4 [&>svg~*]:pl-7 [&>svg+div]:translate-y-[-3px] [&>svg]:absolute [&>svg]:left-4 [&>svg]:top-4 [&>svg]:text-[var(--text-secondary)]',
+  {
+    variants: {
+      variant: {
+        default: 'bg-[var(--background)] text-[var(--text-primary)] border-[var(--border)]',
+        destructive:
+          'border-[var(--error-border)] bg-[var(--error-bg)] text-[var(--error)] [&>svg]:text-[var(--error)]',
+        success:
+          'border-[var(--success-border)] bg-[var(--success-bg)] text-[var(--success)] [&>svg]:text-[var(--success)]',
+        warning:
+          'border-[var(--warning-border)] bg-[var(--warning-bg)] text-[var(--warning)] [&>svg]:text-[var(--warning)]',
+      },
+    },
+    defaultVariants: {
+      variant: 'default',
+    },
+  }
+);
+
+const Alert = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement> & VariantProps<typeof alertVariants>
+>(({ className, variant, ...props }, ref) => (
+  <div
+    ref={ref}
+    role="alert"
+    className={cn(alertVariants({ variant }), className)}
+    {...props}
+  />
+));
+Alert.displayName = 'Alert';
+
+const AlertTitle = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLHeadingElement>
+>(({ className, ...props }, ref) => (
+  <h5
+    ref={ref}
+    className={cn('mb-1 font-medium leading-none tracking-tight', className)}
+    {...props}
+  />
+));
+AlertTitle.displayName = 'AlertTitle';
+
+const AlertDescription = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLParagraphElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn('text-sm [&_p]:leading-relaxed', className)}
+    {...props}
+  />
+));
+AlertDescription.displayName = 'AlertDescription';
+
+export { Alert, AlertTitle, AlertDescription, alertVariants };
diff --git a/internal/adapter/templates/templates/skeleton/packages/ui/src/components/DropdownMenu.tsx b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/DropdownMenu.tsx
new file mode 100644
index 0000000..1263de6
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/DropdownMenu.tsx
@@ -0,0 +1,189 @@
+import * as React from 'react';
+import * as DropdownMenuPrimitive from '@radix-ui/react-dropdown-menu';
+import { Check, ChevronRight, Circle } from 'lucide-react';
+import { cn } from '../utils/cn';
+
+const DropdownMenu = DropdownMenuPrimitive.Root;
+const DropdownMenuTrigger = DropdownMenuPrimitive.Trigger;
+const DropdownMenuGroup = DropdownMenuPrimitive.Group;
+const DropdownMenuPortal = DropdownMenuPrimitive.Portal;
+const DropdownMenuSub = DropdownMenuPrimitive.Sub;
+const DropdownMenuRadioGroup = DropdownMenuPrimitive.RadioGroup;
+
+const DropdownMenuSubTrigger = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.SubTrigger>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.SubTrigger> & {
+    inset?: boolean;
+  }
+>(({ className, inset, children, ...props }, ref) => (
+  <DropdownMenuPrimitive.SubTrigger
+    ref={ref}
+    className={cn(
+      'flex cursor-default select-none items-center rounded-sm px-2 py-1.5 text-sm outline-none focus:bg-[var(--surface-200)] data-[state=open]:bg-[var(--surface-200)]',
+      inset && 'pl-8',
+      className
+    )}
+    {...props}
+  >
+    {children}
+    <ChevronRight className="ml-auto h-4 w-4" />
+  </DropdownMenuPrimitive.SubTrigger>
+));
+DropdownMenuSubTrigger.displayName = DropdownMenuPrimitive.SubTrigger.displayName;
+
+const DropdownMenuSubContent = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.SubContent>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.SubContent>
+>(({ className, ...props }, ref) => (
+  <DropdownMenuPrimitive.SubContent
+    ref={ref}
+    className={cn(
+      'z-[var(--z-popover)] min-w-[8rem] overflow-hidden rounded-md border border-[var(--border)] bg-[var(--surface-100)] p-1 text-[var(--text-primary)] shadow-lg data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2',
+      className
+    )}
+    {...props}
+  />
+));
+DropdownMenuSubContent.displayName = DropdownMenuPrimitive.SubContent.displayName;
+
+const DropdownMenuContent = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.Content>
+>(({ className, sideOffset = 4, ...props }, ref) => (
+  <DropdownMenuPrimitive.Portal>
+    <DropdownMenuPrimitive.Content
+      ref={ref}
+      sideOffset={sideOffset}
+      className={cn(
+        'z-[var(--z-popover)] min-w-[8rem] overflow-hidden rounded-md border border-[var(--border)] bg-[var(--surface-100)] p-1 text-[var(--text-primary)] shadow-md data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2',
+        className
+      )}
+      {...props}
+    />
+  </DropdownMenuPrimitive.Portal>
+));
+DropdownMenuContent.displayName = DropdownMenuPrimitive.Content.displayName;
+
+const DropdownMenuItem = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.Item>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.Item> & {
+    inset?: boolean;
+  }
+>(({ className, inset, ...props }, ref) => (
+  <DropdownMenuPrimitive.Item
+    ref={ref}
+    className={cn(
+      'relative flex cursor-default select-none items-center rounded-sm px-2 py-1.5 text-sm outline-none transition-colors focus:bg-[var(--surface-200)] focus:text-[var(--text-primary)] data-[disabled]:pointer-events-none data-[disabled]:opacity-50',
+      inset && 'pl-8',
+      className
+    )}
+    {...props}
+  />
+));
+DropdownMenuItem.displayName = DropdownMenuPrimitive.Item.displayName;
+
+const DropdownMenuCheckboxItem = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.CheckboxItem>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.CheckboxItem>
+>(({ className, children, checked, ...props }, ref) => (
+  <DropdownMenuPrimitive.CheckboxItem
+    ref={ref}
+    className={cn(
+      'relative flex cursor-default select-none items-center rounded-sm py-1.5 pl-8 pr-2 text-sm outline-none transition-colors focus:bg-[var(--surface-200)] focus:text-[var(--text-primary)] data-[disabled]:pointer-events-none data-[disabled]:opacity-50',
+      className
+    )}
+    checked={checked}
+    {...props}
+  >
+    <span className="absolute left-2 flex h-3.5 w-3.5 items-center justify-center">
+      <DropdownMenuPrimitive.ItemIndicator>
+        <Check className="h-4 w-4" />
+      </DropdownMenuPrimitive.ItemIndicator>
+    </span>
+    {children}
+  </DropdownMenuPrimitive.CheckboxItem>
+));
+DropdownMenuCheckboxItem.displayName = DropdownMenuPrimitive.CheckboxItem.displayName;
+
+const DropdownMenuRadioItem = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.RadioItem>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.RadioItem>
+>(({ className, children, ...props }, ref) => (
+  <DropdownMenuPrimitive.RadioItem
+    ref={ref}
+    className={cn(
+      'relative flex cursor-default select-none items-center rounded-sm py-1.5 pl-8 pr-2 text-sm outline-none transition-colors focus:bg-[var(--surface-200)] focus:text-[var(--text-primary)] data-[disabled]:pointer-events-none data-[disabled]:opacity-50',
+      className
+    )}
+    {...props}
+  >
+    <span className="absolute left-2 flex h-3.5 w-3.5 items-center justify-center">
+      <DropdownMenuPrimitive.ItemIndicator>
+        <Circle className="h-2 w-2 fill-current" />
+      </DropdownMenuPrimitive.ItemIndicator>
+    </span>
+    {children}
+  </DropdownMenuPrimitive.RadioItem>
+));
+DropdownMenuRadioItem.displayName = DropdownMenuPrimitive.RadioItem.displayName;
+
+const DropdownMenuLabel = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.Label>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.Label> & {
+    inset?: boolean;
+  }
+>(({ className, inset, ...props }, ref) => (
+  <DropdownMenuPrimitive.Label
+    ref={ref}
+    className={cn(
+      'px-2 py-1.5 text-sm font-semibold',
+      inset && 'pl-8',
+      className
+    )}
+    {...props}
+  />
+));
+DropdownMenuLabel.displayName = DropdownMenuPrimitive.Label.displayName;
+
+const DropdownMenuSeparator = React.forwardRef<
+  React.ElementRef<typeof DropdownMenuPrimitive.Separator>,
+  React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.Separator>
+>(({ className, ...props }, ref) => (
+  <DropdownMenuPrimitive.Separator
+    ref={ref}
+    className={cn('-mx-1 my-1 h-px bg-[var(--border)]', className)}
+    {...props}
+  />
+));
+DropdownMenuSeparator.displayName = DropdownMenuPrimitive.Separator.displayName;
+
+const DropdownMenuShortcut = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLSpanElement>) => {
+  return (
+    <span
+      className={cn('ml-auto text-xs tracking-widest text-[var(--text-muted)]', className)}
+      {...props}
+    />
+  );
+};
+DropdownMenuShortcut.displayName = 'DropdownMenuShortcut';
+
+export {
+  DropdownMenu,
+  DropdownMenuTrigger,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuCheckboxItem,
+  DropdownMenuRadioItem,
+  DropdownMenuLabel,
+  DropdownMenuSeparator,
+  DropdownMenuShortcut,
+  DropdownMenuGroup,
+  DropdownMenuPortal,
+  DropdownMenuSub,
+  DropdownMenuSubContent,
+  DropdownMenuSubTrigger,
+  DropdownMenuRadioGroup,
+};
diff --git a/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Sheet.tsx b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Sheet.tsx
new file mode 100644
index 0000000..beea11a
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Sheet.tsx
@@ -0,0 +1,134 @@
+import * as React from 'react';
+import * as SheetPrimitive from '@radix-ui/react-dialog';
+import { cva, type VariantProps } from 'class-variance-authority';
+import { X } from 'lucide-react';
+import { cn } from '../utils/cn';
+
+const Sheet = SheetPrimitive.Root;
+const SheetTrigger = SheetPrimitive.Trigger;
+const SheetClose = SheetPrimitive.Close;
+const SheetPortal = SheetPrimitive.Portal;
+
+const SheetOverlay = React.forwardRef<
+  React.ElementRef<typeof SheetPrimitive.Overlay>,
+  React.ComponentPropsWithoutRef<typeof SheetPrimitive.Overlay>
+>(({ className, ...props }, ref) => (
+  <SheetPrimitive.Overlay
+    className={cn(
+      'fixed inset-0 z-[var(--z-modal)] bg-black/80 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0',
+      className
+    )}
+    {...props}
+    ref={ref}
+  />
+));
+SheetOverlay.displayName = SheetPrimitive.Overlay.displayName;
+
+const sheetVariants = cva(
+  'fixed z-[var(--z-modal)] gap-4 bg-[var(--background)] p-6 shadow-lg transition ease-in-out data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:duration-300 data-[state=open]:duration-500',
+  {
+    variants: {
+      side: {
+        top: 'inset-x-0 top-0 border-b border-[var(--border)] data-[state=closed]:slide-out-to-top data-[state=open]:slide-in-from-top',
+        bottom:
+          'inset-x-0 bottom-0 border-t border-[var(--border)] data-[state=closed]:slide-out-to-bottom data-[state=open]:slide-in-from-bottom',
+        left: 'inset-y-0 left-0 h-full w-3/4 border-r border-[var(--border)] data-[state=closed]:slide-out-to-left data-[state=open]:slide-in-from-left sm:max-w-sm',
+        right:
+          'inset-y-0 right-0 h-full w-3/4 border-l border-[var(--border)] data-[state=closed]:slide-out-to-right data-[state=open]:slide-in-from-right sm:max-w-sm',
+      },
+    },
+    defaultVariants: {
+      side: 'right',
+    },
+  }
+);
+
+interface SheetContentProps
+  extends React.ComponentPropsWithoutRef<typeof SheetPrimitive.Content>,
+    VariantProps<typeof sheetVariants> {}
+
+const SheetContent = React.forwardRef<
+  React.ElementRef<typeof SheetPrimitive.Content>,
+  SheetContentProps
+>(({ side = 'right', className, children, ...props }, ref) => (
+  <SheetPortal>
+    <SheetOverlay />
+    <SheetPrimitive.Content
+      ref={ref}
+      className={cn(sheetVariants({ side }), className)}
+      {...props}
+    >
+      {children}
+      <SheetPrimitive.Close className="absolute right-4 top-4 rounded-sm opacity-70 ring-offset-[var(--background)] transition-opacity hover:opacity-100 focus:outline-none focus:ring-2 focus:ring-[var(--accent)] focus:ring-offset-2 disabled:pointer-events-none data-[state=open]:bg-[var(--surface-100)]">
+        <X className="h-4 w-4" />
+        <span className="sr-only">Close</span>
+      </SheetPrimitive.Close>
+    </SheetPrimitive.Content>
+  </SheetPortal>
+));
+SheetContent.displayName = SheetPrimitive.Content.displayName;
+
+const SheetHeader = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) => (
+  <div
+    className={cn(
+      'flex flex-col space-y-2 text-center sm:text-left',
+      className
+    )}
+    {...props}
+  />
+);
+SheetHeader.displayName = 'SheetHeader';
+
+const SheetFooter = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) => (
+  <div
+    className={cn(
+      'flex flex-col-reverse sm:flex-row sm:justify-end sm:space-x-2',
+      className
+    )}
+    {...props}
+  />
+);
+SheetFooter.displayName = 'SheetFooter';
+
+const SheetTitle = React.forwardRef<
+  React.ElementRef<typeof SheetPrimitive.Title>,
+  React.ComponentPropsWithoutRef<typeof SheetPrimitive.Title>
+>(({ className, ...props }, ref) => (
+  <SheetPrimitive.Title
+    ref={ref}
+    className={cn('text-lg font-semibold text-[var(--text-primary)]', className)}
+    {...props}
+  />
+));
+SheetTitle.displayName = SheetPrimitive.Title.displayName;
+
+const SheetDescription = React.forwardRef<
+  React.ElementRef<typeof SheetPrimitive.Description>,
+  React.ComponentPropsWithoutRef<typeof SheetPrimitive.Description>
+>(({ className, ...props }, ref) => (
+  <SheetPrimitive.Description
+    ref={ref}
+    className={cn('text-sm text-[var(--text-muted)]', className)}
+    {...props}
+  />
+));
+SheetDescription.displayName = SheetPrimitive.Description.displayName;
+
+export {
+  Sheet,
+  SheetPortal,
+  SheetOverlay,
+  SheetTrigger,
+  SheetClose,
+  SheetContent,
+  SheetHeader,
+  SheetFooter,
+  SheetTitle,
+  SheetDescription,
+};
diff --git a/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Textarea.tsx b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Textarea.tsx
new file mode 100644
index 0000000..f27eca2
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/packages/ui/src/components/Textarea.tsx
@@ -0,0 +1,23 @@
+import * as React from 'react';
+import { cn } from '../utils/cn';
+
+export interface TextareaProps
+  extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {}
+
+const Textarea = React.forwardRef<HTMLTextAreaElement, TextareaProps>(
+  ({ className, ...props }, ref) => {
+    return (
+      <textarea
+        className={cn(
+          'flex min-h-[80px] w-full rounded-md border border-[var(--border)] bg-[var(--surface-100)] px-3 py-2 text-sm text-[var(--text-primary)] ring-offset-[var(--background)] placeholder:text-[var(--text-muted)] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--accent)] focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50',
+          className
+        )}
+        ref={ref}
+        {...props}
+      />
+    );
+  }
+);
+Textarea.displayName = 'Textarea';
+
+export { Textarea };
diff --git a/internal/adapter/templates/templates/skeleton/packages/ui/src/index.ts b/internal/adapter/templates/templates/skeleton/packages/ui/src/index.ts
index c3aa2af..693319c 100644
--- a/internal/adapter/templates/templates/skeleton/packages/ui/src/index.ts
+++ b/internal/adapter/templates/templates/skeleton/packages/ui/src/index.ts
@@ -11,6 +11,10 @@ export { Dialog, DialogTrigger, DialogContent, DialogHeader, DialogTitle, Dialog
 export { Table, TableHeader, TableBody, TableRow, TableHead, TableCell } from './components/Table';
 export { Select, SelectTrigger, SelectContent, SelectItem, SelectValue } from './components/Select';
 export { Checkbox, type CheckboxProps } from './components/Checkbox';
+export { Alert, AlertTitle, AlertDescription } from './components/Alert';
+export { Textarea, type TextareaProps } from './components/Textarea';
+export { DropdownMenu, DropdownMenuTrigger, DropdownMenuContent, DropdownMenuItem, DropdownMenuCheckboxItem, DropdownMenuRadioItem, DropdownMenuLabel, DropdownMenuSeparator, DropdownMenuShortcut, DropdownMenuGroup, DropdownMenuPortal, DropdownMenuSub, DropdownMenuSubContent, DropdownMenuSubTrigger, DropdownMenuRadioGroup } from './components/DropdownMenu';
+export { Sheet, SheetPortal, SheetOverlay, SheetTrigger, SheetClose, SheetContent, SheetHeader, SheetFooter, SheetTitle, SheetDescription } from './components/Sheet';
 
 // Icons (re-export commonly used ones)
 export {
diff --git a/internal/adapter/templates/templates/skeleton/pkg/app/app.go.tmpl b/internal/adapter/templates/templates/skeleton/pkg/app/app.go.tmpl
index 5803ecc..b9ec81b 100644
--- a/internal/adapter/templates/templates/skeleton/pkg/app/app.go.tmpl
+++ b/internal/adapter/templates/templates/skeleton/pkg/app/app.go.tmpl
@@ -27,6 +27,7 @@ import (
 	"{{GO_MODULE}}/pkg/httpresponse"
 	"{{GO_MODULE}}/pkg/logging"
 	"{{GO_MODULE}}/pkg/middleware"
+	"{{GO_MODULE}}/pkg/openapi"
 )
 
 // Router is an alias for chi.Router, exposing it for handler mounting.
@@ -291,6 +292,19 @@ func (a *App) ListenAddr() string {
 	return a.serverConfig.Addr()
 }
 
+// EnableDocs adds /docs and /openapi.json endpoints to the application.
+// It mounts the Scalar UI at /docs and the OpenAPI JSON spec at /openapi.json.
+//
+// Example:
+//
+//	spec := openapi.NewOpenAPISpec("My Service", "1.0.0")
+//	// ... add paths and schemas ...
+//	application.EnableDocs(spec)
+func (a *App) EnableDocs(spec *openapi.OpenAPISpec) {
+	openapi.Mount(a.router, spec)
+	a.logger.Info("API documentation enabled", "docs", "/docs", "spec", "/openapi.json")
+}
+
 // ServeHTTP implements http.Handler, allowing App to be used in tests.
 func (a *App) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	a.router.ServeHTTP(w, r)
diff --git a/internal/adapter/templates/templates/skeleton/pkg/chassis/chassis.go.tmpl b/internal/adapter/templates/templates/skeleton/pkg/chassis/chassis.go.tmpl
new file mode 100644
index 0000000..d24f163
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/pkg/chassis/chassis.go.tmpl
@@ -0,0 +1,37 @@
+// Package chassis is the service framework for {{PROJECT_NAME}}.
+// It re-exports key types from pkg/app, pkg/httperror, pkg/httpresponse,
+// and pkg/httpvalidation for convenience.
+//
+// Example:
+//
+//	func main() {
+//	    svc := chassis.New("my-service", chassis.WithDefaultPort(8080))
+//	    svc.GET("/users/{id}", app.Wrap(handlers.GetUser))
+//	    svc.Run()
+//	}
+package chassis
+
+import "{{GO_MODULE}}/pkg/app"
+
+// Re-export core types
+type App = app.App
+type Router = app.Router
+type Option = app.Option
+type HandlerFunc = app.HandlerFunc
+type HealthChecker = app.HealthChecker
+type HealthConfig = app.HealthConfig
+
+// Re-export constructors
+var (
+	New              = app.New
+	WithDefaultPort  = app.WithDefaultPort
+	WithLogger       = app.WithLogger
+	Wrap             = app.Wrap
+	WrapWithLogger   = app.WrapWithLogger
+	Bind             = app.Bind
+	BindAndValidate  = app.BindAndValidate
+	BindStrict       = app.BindStrict
+	NewHealthHandler = app.NewHealthHandler
+	PingChecker      = app.PingChecker
+	HTTPChecker      = app.HTTPChecker
+)
diff --git a/internal/adapter/templates/templates/skeleton/pkg/go.mod.tmpl b/internal/adapter/templates/templates/skeleton/pkg/go.mod.tmpl
index b675191..5408061 100644
--- a/internal/adapter/templates/templates/skeleton/pkg/go.mod.tmpl
+++ b/internal/adapter/templates/templates/skeleton/pkg/go.mod.tmpl
@@ -3,9 +3,11 @@ module {{GO_MODULE}}/pkg
 go 1.23
 
 require (
+	github.com/bdpiprava/scalar-go v0.1.2
 	github.com/go-chi/chi/v5 v5.2.0
 	github.com/go-chi/cors v1.2.1
 	github.com/go-playground/validator/v10 v10.23.0
+	github.com/golang-jwt/jwt/v5 v5.2.1
 	github.com/google/uuid v1.6.0
 	github.com/spf13/viper v1.19.0
 )
diff --git a/internal/adapter/templates/templates/skeleton/pkg/openapi/docs.go.tmpl b/internal/adapter/templates/templates/skeleton/pkg/openapi/docs.go.tmpl
new file mode 100644
index 0000000..7ced3a6
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/pkg/openapi/docs.go.tmpl
@@ -0,0 +1,49 @@
+package openapi
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	scalargo "github.com/bdpiprava/scalar-go"
+)
+
+// Mount registers /docs and /openapi.json endpoints on the router.
+func Mount(r chi.Router, spec *OpenAPISpec) {
+	// Serve OpenAPI JSON
+	r.Get("/openapi.json", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+
+		specBytes, err := spec.JSON()
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		_, _ = w.Write(specBytes)
+	})
+
+	// Serve Scalar docs UI
+	r.Get("/docs", func(w http.ResponseWriter, r *http.Request) {
+		scheme := "http"
+		if proto := r.Header.Get("X-Forwarded-Proto"); proto != "" {
+			scheme = proto
+		} else if r.TLS != nil {
+			scheme = "https"
+		}
+		specURL := fmt.Sprintf("%s://%s/openapi.json", scheme, r.Host)
+
+		html, err := scalargo.NewV2(
+			scalargo.WithSpecURL(specURL),
+			scalargo.WithDarkMode(),
+		)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		_, _ = fmt.Fprint(w, html)
+	})
+}
diff --git a/internal/adapter/templates/templates/skeleton/pkg/openapi/params.go.tmpl b/internal/adapter/templates/templates/skeleton/pkg/openapi/params.go.tmpl
new file mode 100644
index 0000000..42415fe
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/pkg/openapi/params.go.tmpl
@@ -0,0 +1,188 @@
+package openapi
+
+import "strings"
+
+// Parameter represents an OpenAPI parameter.
+type Parameter map[string]any
+
+// PathParam creates a required path parameter.
+func PathParam(name, description string) Parameter {
+	return Parameter{
+		"name":        name,
+		"in":          "path",
+		"required":    true,
+		"description": description,
+		"schema":      String(),
+	}
+}
+
+// PathParamWithSchema creates a required path parameter with a custom schema.
+func PathParamWithSchema(name, description string, schema Schema) Parameter {
+	return Parameter{
+		"name":        name,
+		"in":          "path",
+		"required":    true,
+		"description": description,
+		"schema":      schema,
+	}
+}
+
+// QueryParam creates a query parameter.
+func QueryParam(name, description string, required bool) Parameter {
+	return Parameter{
+		"name":        name,
+		"in":          "query",
+		"required":    required,
+		"description": description,
+		"schema":      String(),
+	}
+}
+
+// QueryParamWithSchema creates a query parameter with a custom schema.
+func QueryParamWithSchema(name, description string, required bool, schema Schema) Parameter {
+	return Parameter{
+		"name":        name,
+		"in":          "query",
+		"required":    required,
+		"description": description,
+		"schema":      schema,
+	}
+}
+
+// HeaderParam creates a header parameter.
+func HeaderParam(name, description string, required bool) Parameter {
+	return Parameter{
+		"name":        name,
+		"in":          "header",
+		"required":    required,
+		"description": description,
+		"schema":      String(),
+	}
+}
+
+// CookieParam creates a cookie parameter.
+func CookieParam(name, description string, required bool) Parameter {
+	return Parameter{
+		"name":        name,
+		"in":          "cookie",
+		"required":    required,
+		"description": description,
+		"schema":      String(),
+	}
+}
+
+// WithExample adds an example to a parameter.
+func (p Parameter) WithExample(example any) Parameter {
+	p["example"] = example
+	return p
+}
+
+// WithDefault adds a default value to a parameter.
+func (p Parameter) WithDefault(value any) Parameter {
+	if schema, ok := p["schema"].(Schema); ok {
+		schema["default"] = value
+		p["schema"] = schema
+	}
+	return p
+}
+
+// WithDeprecated marks a parameter as deprecated.
+func (p Parameter) WithDeprecated(deprecated bool) Parameter {
+	p["deprecated"] = deprecated
+	return p
+}
+
+// IDParam creates a standard ID path parameter.
+func IDParam() Parameter {
+	return PathParamWithSchema("id", "Resource identifier", UUID())
+}
+
+// PageParam creates a standard pagination page parameter.
+func PageParam() Parameter {
+	return QueryParamWithSchema("page", "Page number (1-indexed)", false, Int().WithDefault(1))
+}
+
+// PerPageParam creates a standard items-per-page parameter.
+func PerPageParam() Parameter {
+	return QueryParamWithSchema("per_page", "Items per page (max 100)", false, IntWithMinMax(1, 100).WithDefault(20))
+}
+
+// SortParam creates a sort parameter.
+func SortParam(allowedFields ...string) Parameter {
+	desc := "Sort field and direction (e.g., name:asc, created_at:desc)"
+	if len(allowedFields) > 0 {
+		desc = "Sort by: " + strings.Join(allowedFields, ", ") + " (append :asc or :desc)"
+	}
+	return QueryParamWithSchema("sort", desc, false,
+		String().WithExample("created_at:desc"))
+}
+
+// SearchParam creates a search query parameter.
+func SearchParam() Parameter {
+	return QueryParam("q", "Search query", false).WithExample("keyword")
+}
+
+// APIKeyHeader creates the X-API-Key header parameter.
+func APIKeyHeader() Parameter {
+	return HeaderParam("X-API-Key", "API key for authentication", true)
+}
+
+// AuthorizationHeader creates the Authorization header parameter.
+func AuthorizationHeader() Parameter {
+	return HeaderParam("Authorization", "Bearer token for authentication", true).
+		WithExample("Bearer eyJhbGciOiJIUzI1NiIs...")
+}
+
+// RequestBody creates a JSON request body.
+func RequestBody(schema Schema, required bool) map[string]any {
+	return map[string]any{
+		"required": required,
+		"content": map[string]any{
+			"application/json": map[string]any{
+				"schema": schema,
+			},
+		},
+	}
+}
+
+// OpResponse creates a response definition for an OpenAPI operation.
+func OpResponse(description string, schema Schema) map[string]any {
+	return map[string]any{
+		"description": description,
+		"content": map[string]any{
+			"application/json": map[string]any{
+				"schema": schema,
+			},
+		},
+	}
+}
+
+// OpResponseNoContent creates a 204 No Content response.
+func OpResponseNoContent() map[string]any {
+	return map[string]any{
+		"description": "No content",
+	}
+}
+
+// OpResponses creates a responses map for an operation.
+func OpResponses(responses map[string]map[string]any) map[string]any {
+	result := make(map[string]any, len(responses))
+	for code, resp := range responses {
+		result[code] = resp
+	}
+	return result
+}
+
+// OpStandardResponses returns common error responses to include in operations.
+func OpStandardResponses() map[string]map[string]any {
+	return map[string]map[string]any{
+		"400": OpResponse("Bad request", ErrorResponseSchema()),
+		"401": OpResponse("Unauthorized", ErrorResponseSchema()),
+		"403": OpResponse("Forbidden", ErrorResponseSchema()),
+		"404": OpResponse("Not found", ErrorResponseSchema()),
+		"422": OpResponse("Unprocessable entity", ErrorResponseSchema()),
+		"429": OpResponse("Too many requests", ErrorResponseSchema()),
+		"500": OpResponse("Internal server error", ErrorResponseSchema()),
+		"503": OpResponse("Service unavailable", ErrorResponseSchema()),
+	}
+}
diff --git a/internal/adapter/templates/templates/skeleton/pkg/openapi/schema.go.tmpl b/internal/adapter/templates/templates/skeleton/pkg/openapi/schema.go.tmpl
new file mode 100644
index 0000000..1c4711b
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/pkg/openapi/schema.go.tmpl
@@ -0,0 +1,231 @@
+package openapi
+
+// Schema represents a JSON Schema for OpenAPI.
+type Schema map[string]any
+
+// String creates a string schema.
+func String() Schema {
+	return Schema{"type": "string"}
+}
+
+// StringWithFormat creates a string schema with a format.
+// Common formats: email, uri, uuid, date, date-time, password
+func StringWithFormat(format string) Schema {
+	return Schema{"type": "string", "format": format}
+}
+
+// StringEnum creates a string schema restricted to specific values.
+func StringEnum(values ...string) Schema {
+	return Schema{"type": "string", "enum": values}
+}
+
+// StringWithMinMax creates a string schema with length constraints.
+func StringWithMinMax(min, max int) Schema {
+	s := Schema{"type": "string"}
+	if min > 0 {
+		s["minLength"] = min
+	}
+	if max > 0 {
+		s["maxLength"] = max
+	}
+	return s
+}
+
+// Int creates an integer schema.
+func Int() Schema {
+	return Schema{"type": "integer"}
+}
+
+// IntWithMinMax creates an integer schema with constraints.
+func IntWithMinMax(min, max int) Schema {
+	s := Schema{"type": "integer"}
+	if min != 0 {
+		s["minimum"] = min
+	}
+	if max != 0 {
+		s["maximum"] = max
+	}
+	return s
+}
+
+// Int64 creates a 64-bit integer schema.
+func Int64() Schema {
+	return Schema{"type": "integer", "format": "int64"}
+}
+
+// Number creates a number (float) schema.
+func Number() Schema {
+	return Schema{"type": "number"}
+}
+
+// Bool creates a boolean schema.
+func Bool() Schema {
+	return Schema{"type": "boolean"}
+}
+
+// Array creates an array schema with the given item type.
+func Array(items Schema) Schema {
+	return Schema{
+		"type":  "array",
+		"items": items,
+	}
+}
+
+// Object creates an object schema with the given properties.
+// Required fields can be specified separately.
+func Object(props map[string]Schema, required ...string) Schema {
+	properties := make(map[string]any, len(props))
+	for k, v := range props {
+		properties[k] = v
+	}
+
+	s := Schema{
+		"type":       "object",
+		"properties": properties,
+	}
+
+	if len(required) > 0 {
+		s["required"] = required
+	}
+
+	return s
+}
+
+// Ref creates a $ref to a schema in components/schemas.
+func Ref(name string) Schema {
+	return Schema{"$ref": "#/components/schemas/" + name}
+}
+
+// RefArray creates an array of $ref items.
+func RefArray(name string) Schema {
+	return Array(Ref(name))
+}
+
+// Nullable makes a schema nullable using oneOf pattern.
+func Nullable(s Schema) Schema {
+	return Schema{
+		"oneOf": []Schema{
+			s,
+			{"type": "null"},
+		},
+	}
+}
+
+// WithDescription adds a description to a schema.
+func (s Schema) WithDescription(desc string) Schema {
+	s["description"] = desc
+	return s
+}
+
+// WithExample adds an example to a schema.
+func (s Schema) WithExample(example any) Schema {
+	s["example"] = example
+	return s
+}
+
+// WithDefault adds a default value to a schema.
+func (s Schema) WithDefault(value any) Schema {
+	s["default"] = value
+	return s
+}
+
+// WithPattern adds a regex pattern to a string schema.
+func (s Schema) WithPattern(pattern string) Schema {
+	s["pattern"] = pattern
+	return s
+}
+
+// Format sets the format for a schema.
+func (s Schema) Format(format string) Schema {
+	s["format"] = format
+	return s
+}
+
+// Description is an alias for WithDescription for cleaner chaining.
+func (s Schema) Description(desc string) Schema {
+	return s.WithDescription(desc)
+}
+
+// Example is an alias for WithExample for cleaner chaining.
+func (s Schema) Example(example any) Schema {
+	return s.WithExample(example)
+}
+
+// Default is an alias for WithDefault for cleaner chaining.
+func (s Schema) Default(value any) Schema {
+	return s.WithDefault(value)
+}
+
+// Pattern is an alias for WithPattern for cleaner chaining.
+func (s Schema) Pattern(pattern string) Schema {
+	return s.WithPattern(pattern)
+}
+
+// UUID creates a UUID string schema.
+func UUID() Schema {
+	return StringWithFormat("uuid").WithExample("550e8400-e29b-41d4-a716-446655440000")
+}
+
+// Email creates an email string schema.
+func Email() Schema {
+	return StringWithFormat("email").WithExample("user@example.com")
+}
+
+// URL creates a URL string schema.
+func URL() Schema {
+	return StringWithFormat("uri").WithExample("https://example.com")
+}
+
+// DateTime creates a date-time string schema.
+func DateTime() Schema {
+	return StringWithFormat("date-time").WithExample("2024-01-15T10:30:00Z")
+}
+
+// Password creates a password string schema (hidden in docs).
+func Password() Schema {
+	return StringWithFormat("password")
+}
+
+// Pagination creates a common pagination object schema.
+func Pagination() Schema {
+	return Object(map[string]Schema{
+		"page":        Int().WithDescription("Current page number").WithExample(1),
+		"per_page":    Int().WithDescription("Items per page").WithExample(20),
+		"total":       Int().WithDescription("Total number of items").WithExample(100),
+		"total_pages": Int().WithDescription("Total number of pages").WithExample(5),
+	})
+}
+
+// ResponseSchema creates the standard response envelope schema.
+func ResponseSchema(dataSchema Schema) Schema {
+	return Object(map[string]Schema{
+		"data": dataSchema,
+		"meta": Object(map[string]Schema{
+			"request_id": String().WithDescription("Request correlation ID"),
+			"timestamp":  DateTime().WithDescription("Response timestamp"),
+		}),
+	})
+}
+
+// ErrorResponseSchema creates the standard error response schema.
+func ErrorResponseSchema() Schema {
+	return Object(map[string]Schema{
+		"error": Object(map[string]Schema{
+			"code":    String().WithDescription("Machine-readable error code").WithExample("BAD_REQUEST"),
+			"message": String().WithDescription("Human-readable error message").WithExample("Invalid request"),
+			"details": Schema{"type": "object"}.WithDescription("Additional error details"),
+		}, "code", "message"),
+		"meta": Object(map[string]Schema{
+			"request_id": String().WithDescription("Request correlation ID"),
+			"timestamp":  DateTime().WithDescription("Response timestamp"),
+		}),
+	})
+}
+
+// ValidationErrorSchema creates a validation error details schema.
+func ValidationErrorSchema() Schema {
+	return Array(Object(map[string]Schema{
+		"field":   String().WithDescription("Field that failed validation").WithExample("email"),
+		"message": String().WithDescription("Validation error message").WithExample("is required"),
+	}, "field", "message"))
+}
diff --git a/internal/adapter/templates/templates/skeleton/pkg/openapi/spec.go.tmpl b/internal/adapter/templates/templates/skeleton/pkg/openapi/spec.go.tmpl
new file mode 100644
index 0000000..861d8ee
--- /dev/null
+++ b/internal/adapter/templates/templates/skeleton/pkg/openapi/spec.go.tmpl
@@ -0,0 +1,229 @@
+// Package openapi provides an OpenAPI 3.0 specification builder and documentation endpoints.
+//
+// It includes:
+//   - OpenAPISpec: A builder for constructing OpenAPI 3.0 specifications
+//   - Schema helpers: Typed schema constructors (String, Int, Object, Array, etc.)
+//   - Parameter helpers: Path, query, header parameter builders
+//   - Documentation: Scalar UI and JSON spec serving via EnableDocs
+//
+// Example:
+//
+//	spec := openapi.NewOpenAPISpec("My Service", "1.0.0").
+//	    WithDescription("Service API documentation").
+//	    WithBearerSecurity("bearer", "JWT authentication")
+//
+//	spec.AddPath("/api/v1/items", "get", map[string]any{
+//	    "summary": "List items",
+//	    "tags":    []string{"Items"},
+//	    "responses": map[string]any{
+//	        "200": openapi.OpResponse("Success", openapi.RefArray("Item")),
+//	    },
+//	})
+//
+//	application.EnableDocs(spec)
+package openapi
+
+import (
+	"encoding/json"
+	"sync"
+)
+
+// OpenAPIInfo contains metadata about the API.
+type OpenAPIInfo struct {
+	Title       string `json:"title"`
+	Description string `json:"description,omitempty"`
+	Version     string `json:"version"`
+}
+
+// OpenAPIServer describes a server endpoint.
+type OpenAPIServer struct {
+	URL         string `json:"url"`
+	Description string `json:"description,omitempty"`
+}
+
+// OpenAPIComponents contains reusable schema definitions.
+type OpenAPIComponents struct {
+	Schemas         map[string]any `json:"schemas,omitempty"`
+	SecuritySchemes map[string]any `json:"securitySchemes,omitempty"`
+}
+
+// OpenAPISpec represents a minimal OpenAPI 3.0 specification.
+type OpenAPISpec struct {
+	OpenAPI    string                    `json:"openapi"`
+	Info       OpenAPIInfo               `json:"info"`
+	Servers    []OpenAPIServer           `json:"servers,omitempty"`
+	Paths      map[string]map[string]any `json:"paths"`
+	Tags       []OpenAPITag              `json:"tags,omitempty"`
+	Components *OpenAPIComponents        `json:"components,omitempty"`
+	Security   []map[string][]string     `json:"security,omitempty"`
+
+	mu sync.RWMutex
+}
+
+// OpenAPITag groups operations together.
+type OpenAPITag struct {
+	Name        string `json:"name"`
+	Description string `json:"description,omitempty"`
+}
+
+// NewOpenAPISpec creates a new OpenAPI specification builder.
+func NewOpenAPISpec(title, version string) *OpenAPISpec {
+	return &OpenAPISpec{
+		OpenAPI: "3.0.3",
+		Info: OpenAPIInfo{
+			Title:   title,
+			Version: version,
+		},
+		Paths: make(map[string]map[string]any),
+	}
+}
+
+// WithDescription sets the API description.
+func (s *OpenAPISpec) WithDescription(desc string) *OpenAPISpec {
+	s.Info.Description = desc
+	return s
+}
+
+// WithServer adds a server to the spec.
+func (s *OpenAPISpec) WithServer(url, description string) *OpenAPISpec {
+	s.Servers = append(s.Servers, OpenAPIServer{
+		URL:         url,
+		Description: description,
+	})
+	return s
+}
+
+// WithTag adds a tag for grouping operations.
+func (s *OpenAPISpec) WithTag(name, description string) *OpenAPISpec {
+	s.Tags = append(s.Tags, OpenAPITag{
+		Name:        name,
+		Description: description,
+	})
+	return s
+}
+
+// AddPath adds an operation to the spec.
+// method should be lowercase (get, post, put, patch, delete).
+func (s *OpenAPISpec) AddPath(path, method string, operation map[string]any) *OpenAPISpec {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.Paths[path] == nil {
+		s.Paths[path] = make(map[string]any)
+	}
+	s.Paths[path][method] = operation
+	return s
+}
+
+// ensureComponents initializes the Components field if nil.
+// Must be called while holding s.mu.
+func (s *OpenAPISpec) ensureComponents() {
+	if s.Components == nil {
+		s.Components = &OpenAPIComponents{
+			Schemas:         make(map[string]any),
+			SecuritySchemes: make(map[string]any),
+		}
+	}
+}
+
+// WithSchema adds a reusable schema to components/schemas.
+func (s *OpenAPISpec) WithSchema(name string, schema Schema) *OpenAPISpec {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.ensureComponents()
+	if s.Components.Schemas == nil {
+		s.Components.Schemas = make(map[string]any)
+	}
+	s.Components.Schemas[name] = schema
+	return s
+}
+
+// WithAPIKeySecurity adds API key security scheme.
+func (s *OpenAPISpec) WithAPIKeySecurity(name, headerName, description string) *OpenAPISpec {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.ensureComponents()
+	if s.Components.SecuritySchemes == nil {
+		s.Components.SecuritySchemes = make(map[string]any)
+	}
+	s.Components.SecuritySchemes[name] = map[string]any{
+		"type":        "apiKey",
+		"in":          "header",
+		"name":        headerName,
+		"description": description,
+	}
+	return s
+}
+
+// WithBearerSecurity adds Bearer token security scheme.
+func (s *OpenAPISpec) WithBearerSecurity(name, description string) *OpenAPISpec {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.ensureComponents()
+	if s.Components.SecuritySchemes == nil {
+		s.Components.SecuritySchemes = make(map[string]any)
+	}
+	s.Components.SecuritySchemes[name] = map[string]any{
+		"type":         "http",
+		"scheme":       "bearer",
+		"bearerFormat": "JWT",
+		"description":  description,
+	}
+	return s
+}
+
+// WithGlobalSecurity sets global security requirements.
+func (s *OpenAPISpec) WithGlobalSecurity(schemeName string) *OpenAPISpec {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.Security = append(s.Security, map[string][]string{
+		schemeName: {},
+	})
+	return s
+}
+
+// JSON returns the spec as JSON bytes.
+func (s *OpenAPISpec) JSON() ([]byte, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return json.MarshalIndent(s, "", "  ")
+}
+
+// Op creates an OpenAPI operation helper.
+func Op(summary, description string, tags ...string) map[string]any {
+	return map[string]any{
+		"summary":     summary,
+		"description": description,
+		"tags":        tags,
+		"responses": map[string]any{
+			"200": map[string]any{"description": "Success"},
+		},
+	}
+}
+
+// OpWithBody creates an OpenAPI operation with a request body.
+func OpWithBody(summary, description string, tags ...string) map[string]any {
+	return map[string]any{
+		"summary":     summary,
+		"description": description,
+		"tags":        tags,
+		"requestBody": map[string]any{
+			"required": true,
+			"content": map[string]any{
+				"application/json": map[string]any{
+					"schema": map[string]any{
+						"type": "object",
+					},
+				},
+			},
+		},
+		"responses": map[string]any{
+			"200": map[string]any{"description": "Success"},
+			"201": map[string]any{"description": "Created"},
+		},
+	}
+}
diff --git a/internal/domain/component.go b/internal/domain/component.go
index 6e9602e..bde0bac 100644
--- a/internal/domain/component.go
+++ b/internal/domain/component.go
@@ -7,11 +7,12 @@ import "regexp"
 type ComponentType string
 
 const (
-	ComponentTypeService  ComponentType = "service"
-	ComponentTypeWorker   ComponentType = "worker"
-	ComponentTypeAppAstro ComponentType = "app-astro"
-	ComponentTypeAppReact ComponentType = "app-react"
-	ComponentTypeCLI      ComponentType = "cli"
+	ComponentTypeService   ComponentType = "service"
+	ComponentTypeWorker    ComponentType = "worker"
+	ComponentTypeAppAstro  ComponentType = "app-astro"
+	ComponentTypeAppReact  ComponentType = "app-react"
+	ComponentTypeAppNextJS ComponentType = "app-nextjs"
+	ComponentTypeCLI       ComponentType = "cli"
 )
 
 // ValidComponentTypes lists all valid component types.
@@ -20,6 +21,7 @@ var ValidComponentTypes = []ComponentType{
 	ComponentTypeWorker,
 	ComponentTypeAppAstro,
 	ComponentTypeAppReact,
+	ComponentTypeAppNextJS,
 	ComponentTypeCLI,
 }
 
@@ -50,7 +52,7 @@ func (c ComponentType) DestDir() string {
 		return "services"
 	case ComponentTypeWorker:
 		return "workers"
-	case ComponentTypeAppAstro, ComponentTypeAppReact:
+	case ComponentTypeAppAstro, ComponentTypeAppReact, ComponentTypeAppNextJS:
 		return "apps"
 	case ComponentTypeCLI:
 		return "cli"
@@ -65,7 +67,7 @@ func (c ComponentType) StartingPort() int {
 	switch c {
 	case ComponentTypeService:
 		return 8001
-	case ComponentTypeAppAstro, ComponentTypeAppReact:
+	case ComponentTypeAppAstro, ComponentTypeAppReact, ComponentTypeAppNextJS:
 		return 3001
 	case ComponentTypeWorker, ComponentTypeCLI:
 		return 0
@@ -76,7 +78,7 @@ func (c ComponentType) StartingPort() int {
 
 // NeedsPort returns true if this component type requires a port assignment.
 func (c ComponentType) NeedsPort() bool {
-	return c == ComponentTypeService || c == ComponentTypeAppAstro || c == ComponentTypeAppReact
+	return c == ComponentTypeService || c == ComponentTypeAppAstro || c == ComponentTypeAppReact || c == ComponentTypeAppNextJS
 }
 
 // IsGoComponent returns true if this component type uses Go (and needs go.work entry).
diff --git a/internal/domain/component_test.go b/internal/domain/component_test.go
index 731fcbb..ff79855 100644
--- a/internal/domain/component_test.go
+++ b/internal/domain/component_test.go
@@ -12,6 +12,7 @@ func TestIsValidComponentType(t *testing.T) {
 		{"worker", "worker", true},
 		{"app-astro", "app-astro", true},
 		{"app-react", "app-react", true},
+		{"app-nextjs", "app-nextjs", true},
 		{"cli", "cli", true},
 		{"invalid", "invalid", false},
 		{"empty", "", false},
@@ -39,6 +40,7 @@ func TestComponentType_DestDir(t *testing.T) {
 		{"worker", ComponentTypeWorker, "workers"},
 		{"app-astro", ComponentTypeAppAstro, "apps"},
 		{"app-react", ComponentTypeAppReact, "apps"},
+		{"app-nextjs", ComponentTypeAppNextJS, "apps"},
 		{"cli", ComponentTypeCLI, "cli"},
 		{"unknown", ComponentType("unknown"), ""},
 	}
@@ -63,6 +65,7 @@ func TestComponentType_StartingPort(t *testing.T) {
 		{"worker", ComponentTypeWorker, 0},
 		{"app-astro", ComponentTypeAppAstro, 3001},
 		{"app-react", ComponentTypeAppReact, 3001},
+		{"app-nextjs", ComponentTypeAppNextJS, 3001},
 		{"cli", ComponentTypeCLI, 0},
 		{"unknown", ComponentType("unknown"), 0},
 	}
@@ -87,6 +90,7 @@ func TestComponentType_NeedsPort(t *testing.T) {
 		{"worker", ComponentTypeWorker, false},
 		{"app-astro", ComponentTypeAppAstro, true},
 		{"app-react", ComponentTypeAppReact, true},
+		{"app-nextjs", ComponentTypeAppNextJS, true},
 		{"cli", ComponentTypeCLI, false},
 	}
 
@@ -110,6 +114,7 @@ func TestComponentType_IsGoComponent(t *testing.T) {
 		{"worker", ComponentTypeWorker, true},
 		{"app-astro", ComponentTypeAppAstro, false},
 		{"app-react", ComponentTypeAppReact, false},
+		{"app-nextjs", ComponentTypeAppNextJS, false},
 		{"cli", ComponentTypeCLI, true},
 	}
 
@@ -161,6 +166,7 @@ func TestValidComponentTypes(t *testing.T) {
 		ComponentTypeWorker,
 		ComponentTypeAppAstro,
 		ComponentTypeAppReact,
+		ComponentTypeAppNextJS,
 		ComponentTypeCLI,
 	}
 
diff --git a/internal/handlers/sdlc.go b/internal/handlers/sdlc.go
new file mode 100644
index 0000000..a304769
--- /dev/null
+++ b/internal/handlers/sdlc.go
@@ -0,0 +1,129 @@
+package handlers
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/internal/domain"
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/orchard9/rdev/internal/service"
+	"github.com/orchard9/rdev/pkg/api"
+)
+
+// SDLCHandler handles SDLC endpoints for project lifecycle management.
+type SDLCHandler struct {
+	sdlcService *service.SDLCService
+	logger      *slog.Logger
+}
+
+// NewSDLCHandler creates a new SDLC handler.
+func NewSDLCHandler(sdlcService *service.SDLCService, logger *slog.Logger) *SDLCHandler {
+	if logger == nil {
+		logger = slog.Default()
+	}
+	return &SDLCHandler{
+		sdlcService: sdlcService,
+		logger:      logger,
+	}
+}
+
+// Mount registers all SDLC routes under /projects/{id}/sdlc/.
+func (h *SDLCHandler) Mount(r api.Router) {
+	r.Route("/projects/{id}/sdlc", func(r chi.Router) {
+		// State
+		r.Get("/state", h.GetState)
+		r.Get("/next", h.GetNext)
+
+		// Features
+		r.Get("/features", h.ListFeatures)
+		r.Post("/features", h.CreateFeature)
+		r.Get("/features/{slug}", h.GetFeature)
+		r.Post("/features/{slug}/transition", h.TransitionFeature)
+		r.Post("/features/{slug}/block", h.BlockFeature)
+		r.Post("/features/{slug}/unblock", h.UnblockFeature)
+		r.Delete("/features/{slug}", h.DeleteFeature)
+
+		// Artifacts
+		r.Get("/features/{slug}/artifacts", h.GetArtifactStatus)
+		r.Post("/features/{slug}/artifacts/{type}/approve", h.ApproveArtifact)
+		r.Post("/features/{slug}/artifacts/{type}/reject", h.RejectArtifact)
+
+		// Tasks
+		r.Get("/features/{slug}/tasks", h.ListTasks)
+		r.Post("/features/{slug}/tasks", h.AddTask)
+		r.Post("/features/{slug}/tasks/{taskId}/start", h.StartTask)
+		r.Post("/features/{slug}/tasks/{taskId}/complete", h.CompleteTask)
+		r.Post("/features/{slug}/tasks/{taskId}/block", h.BlockTask)
+
+		// Queries
+		r.Get("/query/blocked", h.QueryBlocked)
+		r.Get("/query/ready", h.QueryReady)
+		r.Get("/query/needs-approval", h.QueryNeedsApproval)
+	})
+}
+
+// GetState returns the global SDLC state for a project.
+// GET /projects/{id}/sdlc/state
+func (h *SDLCHandler) GetState(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	state, err := h.sdlcService.GetState(ctx, projectID)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, state)
+}
+
+// GetNext returns the classifier's recommendation for the next action.
+// GET /projects/{id}/sdlc/next?feature=slug
+func (h *SDLCHandler) GetNext(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	feature := r.URL.Query().Get("feature")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	cl, err := h.sdlcService.GetNext(ctx, projectID, feature)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, cl)
+}
+
+// writeSDLCError maps SDLC domain errors to HTTP responses.
+func writeSDLCError(w http.ResponseWriter, r *http.Request, err error) {
+	switch {
+	case errors.Is(err, domain.ErrProjectNotFound):
+		api.WriteNotFound(w, r, "project not found")
+	case errors.Is(err, sdlc.ErrNotInitialized):
+		api.WriteNotFound(w, r, "sdlc not initialized for this project")
+	case errors.Is(err, sdlc.ErrFeatureNotFound):
+		api.WriteNotFound(w, r, "feature not found")
+	case errors.Is(err, sdlc.ErrTaskNotFound):
+		api.WriteNotFound(w, r, "task not found")
+	case errors.Is(err, sdlc.ErrArtifactNotFound):
+		api.WriteNotFound(w, r, "artifact not found")
+	case errors.Is(err, sdlc.ErrFeatureExists):
+		api.WriteBadRequest(w, r, "feature already exists")
+	case errors.Is(err, sdlc.ErrInvalidTransition):
+		api.WriteBadRequest(w, r, err.Error())
+	case errors.Is(err, sdlc.ErrInvalidPhase):
+		api.WriteBadRequest(w, r, "invalid phase")
+	case errors.Is(err, sdlc.ErrInvalidSlug):
+		api.WriteBadRequest(w, r, "invalid slug: must be lowercase alphanumeric with hyphens")
+	case errors.Is(err, sdlc.ErrInvalidArtifact):
+		api.WriteBadRequest(w, r, "invalid artifact type")
+	default:
+		api.WriteInternalError(w, r, "sdlc operation failed")
+	}
+}
diff --git a/internal/handlers/sdlc_artifacts.go b/internal/handlers/sdlc_artifacts.go
new file mode 100644
index 0000000..b416837
--- /dev/null
+++ b/internal/handlers/sdlc_artifacts.go
@@ -0,0 +1,84 @@
+package handlers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/orchard9/rdev/pkg/api"
+)
+
+// GetArtifactStatus returns artifact statuses for a feature.
+// GET /projects/{id}/sdlc/features/{slug}/artifacts
+func (h *SDLCHandler) GetArtifactStatus(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	artifacts, err := h.sdlcService.GetArtifactStatus(ctx, projectID, slug)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, artifacts)
+}
+
+// ApproveArtifact approves a feature artifact.
+// POST /projects/{id}/sdlc/features/{slug}/artifacts/{type}/approve
+func (h *SDLCHandler) ApproveArtifact(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+	artTypeStr := chi.URLParam(r, "type")
+
+	artType := sdlc.ArtifactType(artTypeStr)
+	if !sdlc.IsValidArtifactType(artType) {
+		api.WriteBadRequest(w, r, "invalid artifact type: "+artTypeStr)
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.ApproveArtifact(ctx, projectID, slug, artType); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature":  slug,
+		"artifact": artTypeStr,
+		"status":   "approved",
+	})
+}
+
+// RejectArtifact rejects a feature artifact.
+// POST /projects/{id}/sdlc/features/{slug}/artifacts/{type}/reject
+func (h *SDLCHandler) RejectArtifact(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+	artTypeStr := chi.URLParam(r, "type")
+
+	artType := sdlc.ArtifactType(artTypeStr)
+	if !sdlc.IsValidArtifactType(artType) {
+		api.WriteBadRequest(w, r, "invalid artifact type: "+artTypeStr)
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.RejectArtifact(ctx, projectID, slug, artType); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature":  slug,
+		"artifact": artTypeStr,
+		"status":   "rejected",
+	})
+}
diff --git a/internal/handlers/sdlc_features.go b/internal/handlers/sdlc_features.go
new file mode 100644
index 0000000..a26781e
--- /dev/null
+++ b/internal/handlers/sdlc_features.go
@@ -0,0 +1,202 @@
+package handlers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/orchard9/rdev/internal/validate"
+	"github.com/orchard9/rdev/pkg/api"
+)
+
+// CreateFeatureRequest is the request body for POST /projects/{id}/sdlc/features.
+type CreateFeatureRequest struct {
+	Slug  string `json:"slug"`
+	Title string `json:"title"`
+}
+
+// TransitionFeatureRequest is the request body for POST /projects/{id}/sdlc/features/{slug}/transition.
+type TransitionFeatureRequest struct {
+	Phase string `json:"phase"`
+}
+
+// BlockFeatureRequest is the request body for POST /projects/{id}/sdlc/features/{slug}/block.
+type BlockFeatureRequest struct {
+	Reason string `json:"reason"`
+}
+
+// ListFeatures returns all features in a project.
+// GET /projects/{id}/sdlc/features
+func (h *SDLCHandler) ListFeatures(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	features, err := h.sdlcService.ListFeatures(ctx, projectID)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	if features == nil {
+		features = []*sdlc.Feature{}
+	}
+	api.WriteSuccess(w, r, features)
+}
+
+// GetFeature returns a single feature by slug.
+// GET /projects/{id}/sdlc/features/{slug}
+func (h *SDLCHandler) GetFeature(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	feature, err := h.sdlcService.GetFeature(ctx, projectID, slug)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, feature)
+}
+
+// CreateFeature creates a new feature.
+// POST /projects/{id}/sdlc/features
+func (h *SDLCHandler) CreateFeature(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+
+	var req CreateFeatureRequest
+	if err := api.DecodeJSON(r, &req); err != nil {
+		api.WriteBadRequest(w, r, "invalid request body")
+		return
+	}
+
+	v := validate.New()
+	v.Required(req.Slug, "slug")
+	v.Required(req.Title, "title")
+	if err := v.Error(); err != nil {
+		api.WriteBadRequest(w, r, err.Error())
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	feature, err := h.sdlcService.CreateFeature(ctx, projectID, req.Slug, req.Title)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteCreated(w, r, feature)
+}
+
+// TransitionFeature moves a feature to a new phase.
+// POST /projects/{id}/sdlc/features/{slug}/transition
+func (h *SDLCHandler) TransitionFeature(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	var req TransitionFeatureRequest
+	if err := api.DecodeJSON(r, &req); err != nil {
+		api.WriteBadRequest(w, r, "invalid request body")
+		return
+	}
+
+	if req.Phase == "" {
+		api.WriteBadRequest(w, r, "phase is required")
+		return
+	}
+
+	phase := sdlc.FeaturePhase(req.Phase)
+	if !sdlc.IsValidPhase(phase) {
+		api.WriteBadRequest(w, r, "invalid phase: "+req.Phase)
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.TransitionFeature(ctx, projectID, slug, phase); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature": slug,
+		"phase":   req.Phase,
+		"message": "feature transitioned successfully",
+	})
+}
+
+// BlockFeature blocks a feature with a reason.
+// POST /projects/{id}/sdlc/features/{slug}/block
+func (h *SDLCHandler) BlockFeature(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	var req BlockFeatureRequest
+	if err := api.DecodeJSON(r, &req); err != nil {
+		api.WriteBadRequest(w, r, "invalid request body")
+		return
+	}
+
+	if req.Reason == "" {
+		api.WriteBadRequest(w, r, "reason is required")
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.BlockFeature(ctx, projectID, slug, req.Reason); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature": slug,
+		"message": "feature blocked",
+	})
+}
+
+// UnblockFeature removes all blockers from a feature.
+// POST /projects/{id}/sdlc/features/{slug}/unblock
+func (h *SDLCHandler) UnblockFeature(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.UnblockFeature(ctx, projectID, slug); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature": slug,
+		"message": "feature unblocked",
+	})
+}
+
+// DeleteFeature removes a feature.
+// DELETE /projects/{id}/sdlc/features/{slug}
+func (h *SDLCHandler) DeleteFeature(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.DeleteFeature(ctx, projectID, slug); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteNoContent(w)
+}
diff --git a/internal/handlers/sdlc_queries.go b/internal/handlers/sdlc_queries.go
new file mode 100644
index 0000000..6927498
--- /dev/null
+++ b/internal/handlers/sdlc_queries.go
@@ -0,0 +1,60 @@
+package handlers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/pkg/api"
+)
+
+// QueryBlocked returns all blocked features in a project.
+// GET /projects/{id}/sdlc/query/blocked
+func (h *SDLCHandler) QueryBlocked(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	blocked, err := h.sdlcService.QueryBlocked(ctx, projectID)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, blocked)
+}
+
+// QueryReady returns features ready for work in a project.
+// GET /projects/{id}/sdlc/query/ready
+func (h *SDLCHandler) QueryReady(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	ready, err := h.sdlcService.QueryReady(ctx, projectID)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, ready)
+}
+
+// QueryNeedsApproval returns features awaiting approval in a project.
+// GET /projects/{id}/sdlc/query/needs-approval
+func (h *SDLCHandler) QueryNeedsApproval(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	pending, err := h.sdlcService.QueryNeedsApproval(ctx, projectID)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, pending)
+}
diff --git a/internal/handlers/sdlc_tasks.go b/internal/handlers/sdlc_tasks.go
new file mode 100644
index 0000000..0b6285d
--- /dev/null
+++ b/internal/handlers/sdlc_tasks.go
@@ -0,0 +1,134 @@
+package handlers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/orchard9/rdev/internal/validate"
+	"github.com/orchard9/rdev/pkg/api"
+)
+
+// AddTaskRequest is the request body for POST /projects/{id}/sdlc/features/{slug}/tasks.
+type AddTaskRequest struct {
+	Title string `json:"title"`
+}
+
+// ListTasks returns all tasks for a feature.
+// GET /projects/{id}/sdlc/features/{slug}/tasks
+func (h *SDLCHandler) ListTasks(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutStandard)
+	defer cancel()
+
+	tasks, err := h.sdlcService.ListTasks(ctx, projectID, slug)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	if tasks == nil {
+		tasks = []sdlc.Task{}
+	}
+	api.WriteSuccess(w, r, tasks)
+}
+
+// AddTask adds a new task to a feature.
+// POST /projects/{id}/sdlc/features/{slug}/tasks
+func (h *SDLCHandler) AddTask(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+
+	var req AddTaskRequest
+	if err := api.DecodeJSON(r, &req); err != nil {
+		api.WriteBadRequest(w, r, "invalid request body")
+		return
+	}
+
+	v := validate.New()
+	v.Required(req.Title, "title")
+	if err := v.Error(); err != nil {
+		api.WriteBadRequest(w, r, err.Error())
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	task, err := h.sdlcService.AddTask(ctx, projectID, slug, req.Title)
+	if err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteCreated(w, r, task)
+}
+
+// StartTask marks a task as in-progress.
+// POST /projects/{id}/sdlc/features/{slug}/tasks/{taskId}/start
+func (h *SDLCHandler) StartTask(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+	taskID := chi.URLParam(r, "taskId")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.StartTask(ctx, projectID, slug, taskID); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature": slug,
+		"task_id": taskID,
+		"status":  "in_progress",
+	})
+}
+
+// CompleteTask marks a task as complete.
+// POST /projects/{id}/sdlc/features/{slug}/tasks/{taskId}/complete
+func (h *SDLCHandler) CompleteTask(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+	taskID := chi.URLParam(r, "taskId")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.CompleteTask(ctx, projectID, slug, taskID); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature": slug,
+		"task_id": taskID,
+		"status":  "complete",
+	})
+}
+
+// BlockTask marks a task as blocked.
+// POST /projects/{id}/sdlc/features/{slug}/tasks/{taskId}/block
+func (h *SDLCHandler) BlockTask(w http.ResponseWriter, r *http.Request) {
+	projectID := chi.URLParam(r, "id")
+	slug := chi.URLParam(r, "slug")
+	taskID := chi.URLParam(r, "taskId")
+
+	ctx, cancel := context.WithTimeout(r.Context(), TimeoutHeavyWrite)
+	defer cancel()
+
+	if err := h.sdlcService.BlockTask(ctx, projectID, slug, taskID); err != nil {
+		writeSDLCError(w, r, err)
+		return
+	}
+
+	api.WriteSuccess(w, r, map[string]any{
+		"feature": slug,
+		"task_id": taskID,
+		"status":  "blocked",
+	})
+}
diff --git a/internal/handlers/sdlc_test.go b/internal/handlers/sdlc_test.go
new file mode 100644
index 0000000..bd97a18
--- /dev/null
+++ b/internal/handlers/sdlc_test.go
@@ -0,0 +1,399 @@
+package handlers
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/orchard9/rdev/internal/domain"
+	"github.com/orchard9/rdev/internal/port"
+	"github.com/orchard9/rdev/internal/sdlc"
+	"github.com/orchard9/rdev/internal/service"
+)
+
+// testSDLCExecutor implements port.SDLCExecutor for handler tests.
+type testSDLCExecutor struct {
+	state          *sdlc.State
+	classification *sdlc.Classification
+	features       []*sdlc.Feature
+	feature        *sdlc.Feature
+	artifacts      map[sdlc.ArtifactType]*sdlc.Artifact
+	tasks          []sdlc.Task
+	task           *sdlc.Task
+	blocked        []port.BlockedInfo
+	ready          []port.ReadyInfo
+	approval       []port.ApprovalInfo
+	err            error
+}
+
+func (m *testSDLCExecutor) GetState(_ context.Context, _ string) (*sdlc.State, error) {
+	return m.state, m.err
+}
+func (m *testSDLCExecutor) GetNext(_ context.Context, _, _ string) (*sdlc.Classification, error) {
+	return m.classification, m.err
+}
+func (m *testSDLCExecutor) ListFeatures(_ context.Context, _ string) ([]*sdlc.Feature, error) {
+	return m.features, m.err
+}
+func (m *testSDLCExecutor) GetFeature(_ context.Context, _, _ string) (*sdlc.Feature, error) {
+	return m.feature, m.err
+}
+func (m *testSDLCExecutor) CreateFeature(_ context.Context, _, slug, title string) (*sdlc.Feature, error) {
+	if m.err != nil {
+		return nil, m.err
+	}
+	return &sdlc.Feature{Slug: slug, Title: title, Phase: sdlc.PhaseDraft}, nil
+}
+func (m *testSDLCExecutor) TransitionFeature(_ context.Context, _, _ string, _ sdlc.FeaturePhase) error {
+	return m.err
+}
+func (m *testSDLCExecutor) BlockFeature(_ context.Context, _, _, _ string) error { return m.err }
+func (m *testSDLCExecutor) UnblockFeature(_ context.Context, _, _ string) error  { return m.err }
+func (m *testSDLCExecutor) DeleteFeature(_ context.Context, _, _ string) error   { return m.err }
+func (m *testSDLCExecutor) GetArtifactStatus(_ context.Context, _, _ string) (map[sdlc.ArtifactType]*sdlc.Artifact, error) {
+	return m.artifacts, m.err
+}
+func (m *testSDLCExecutor) ApproveArtifact(_ context.Context, _, _ string, _ sdlc.ArtifactType) error {
+	return m.err
+}
+func (m *testSDLCExecutor) RejectArtifact(_ context.Context, _, _ string, _ sdlc.ArtifactType) error {
+	return m.err
+}
+func (m *testSDLCExecutor) ListTasks(_ context.Context, _, _ string) ([]sdlc.Task, error) {
+	return m.tasks, m.err
+}
+func (m *testSDLCExecutor) AddTask(_ context.Context, _, _, title string) (*sdlc.Task, error) {
+	if m.err != nil {
+		return nil, m.err
+	}
+	if m.task != nil {
+		return m.task, nil
+	}
+	return &sdlc.Task{ID: "task-001", Title: title, Status: sdlc.TaskPending}, nil
+}
+func (m *testSDLCExecutor) StartTask(_ context.Context, _, _, _ string) error    { return m.err }
+func (m *testSDLCExecutor) CompleteTask(_ context.Context, _, _, _ string) error { return m.err }
+func (m *testSDLCExecutor) BlockTask(_ context.Context, _, _, _ string) error    { return m.err }
+func (m *testSDLCExecutor) QueryBlocked(_ context.Context, _ string) ([]port.BlockedInfo, error) {
+	return m.blocked, m.err
+}
+func (m *testSDLCExecutor) QueryReady(_ context.Context, _ string) ([]port.ReadyInfo, error) {
+	return m.ready, m.err
+}
+func (m *testSDLCExecutor) QueryNeedsApproval(_ context.Context, _ string) ([]port.ApprovalInfo, error) {
+	return m.approval, m.err
+}
+
+// testSDLCProjectRepo implements port.ProjectRepository for handler tests.
+type testSDLCProjectRepo struct {
+	project *domain.Project
+}
+
+func (m *testSDLCProjectRepo) Get(_ context.Context, _ domain.ProjectID) (*domain.Project, error) {
+	if m.project == nil {
+		return nil, domain.ErrProjectNotFound
+	}
+	return m.project, nil
+}
+func (m *testSDLCProjectRepo) List(_ context.Context) ([]domain.Project, error) { return nil, nil }
+func (m *testSDLCProjectRepo) Exists(_ context.Context, _ domain.ProjectID) (bool, error) {
+	return m.project != nil, nil
+}
+func (m *testSDLCProjectRepo) Register(_ context.Context, _ *domain.Project) error    { return nil }
+func (m *testSDLCProjectRepo) Unregister(_ context.Context, _ domain.ProjectID) error { return nil }
+func (m *testSDLCProjectRepo) RefreshStatus(_ context.Context) error                  { return nil }
+
+func setupSDLCHandler(exec *testSDLCExecutor) (*SDLCHandler, *chi.Mux) {
+	repo := &testSDLCProjectRepo{
+		project: &domain.Project{ID: "test-project", PodName: "test-pod"},
+	}
+	svc := service.NewSDLCService(exec, repo, service.SDLCServiceConfig{})
+	handler := NewSDLCHandler(svc, nil)
+	r := chi.NewRouter()
+	handler.Mount(r)
+	return handler, r
+}
+
+func TestSDLCHandler_GetState(t *testing.T) {
+	exec := &testSDLCExecutor{
+		state: &sdlc.State{Version: 1},
+	}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodGet, "/projects/test-project/sdlc/state", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_GetState_NotInitialized(t *testing.T) {
+	exec := &testSDLCExecutor{
+		err: sdlc.ErrNotInitialized,
+	}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodGet, "/projects/test-project/sdlc/state", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Errorf("expected status 404, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_GetState_ProjectNotFound(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	repo := &testSDLCProjectRepo{project: nil}
+	svc := service.NewSDLCService(exec, repo, service.SDLCServiceConfig{})
+	handler := NewSDLCHandler(svc, nil)
+	r := chi.NewRouter()
+	handler.Mount(r)
+
+	req := httptest.NewRequest(http.MethodGet, "/projects/nonexistent/sdlc/state", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Errorf("expected status 404, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_CreateFeature(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(CreateFeatureRequest{Slug: "auth-flow", Title: "Auth Flow"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusCreated {
+		t.Errorf("expected status 201, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_CreateFeature_MissingFields(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(CreateFeatureRequest{})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_CreateFeature_AlreadyExists(t *testing.T) {
+	exec := &testSDLCExecutor{err: sdlc.ErrFeatureExists}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(CreateFeatureRequest{Slug: "auth-flow", Title: "Auth Flow"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_TransitionFeature(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(TransitionFeatureRequest{Phase: "specified"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/transition", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_TransitionFeature_InvalidPhase(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(TransitionFeatureRequest{Phase: "not-a-phase"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/transition", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_TransitionFeature_InvalidTransition(t *testing.T) {
+	exec := &testSDLCExecutor{err: sdlc.ErrInvalidTransition}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(TransitionFeatureRequest{Phase: "review"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/transition", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_BlockFeature(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(BlockFeatureRequest{Reason: "needs API key"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/block", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_BlockFeature_MissingReason(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(BlockFeatureRequest{})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/block", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_DeleteFeature(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodDelete, "/projects/test-project/sdlc/features/auth-flow", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNoContent {
+		t.Errorf("expected status 204, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_DeleteFeature_NotFound(t *testing.T) {
+	exec := &testSDLCExecutor{err: sdlc.ErrFeatureNotFound}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodDelete, "/projects/test-project/sdlc/features/nonexistent", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Errorf("expected status 404, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_ApproveArtifact(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/artifacts/spec/approve", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_ApproveArtifact_InvalidType(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/artifacts/invalid/approve", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_AddTask(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(AddTaskRequest{Title: "Add login form"})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/tasks", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusCreated {
+		t.Errorf("expected status 201, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_AddTask_MissingTitle(t *testing.T) {
+	exec := &testSDLCExecutor{}
+	_, router := setupSDLCHandler(exec)
+
+	body, _ := json.Marshal(AddTaskRequest{})
+	req := httptest.NewRequest(http.MethodPost, "/projects/test-project/sdlc/features/auth-flow/tasks", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected status 400, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_QueryBlocked(t *testing.T) {
+	exec := &testSDLCExecutor{
+		blocked: []port.BlockedInfo{
+			{Slug: "auth", Phase: "implementation", Blockers: []string{"needs API key"}},
+		},
+	}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodGet, "/projects/test-project/sdlc/query/blocked", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSDLCHandler_InternalError(t *testing.T) {
+	exec := &testSDLCExecutor{err: errors.New("something unexpected")}
+	_, router := setupSDLCHandler(exec)
+
+	req := httptest.NewRequest(http.MethodGet, "/projects/test-project/sdlc/state", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusInternalServerError {
+		t.Errorf("expected status 500, got %d: %s", w.Code, w.Body.String())
+	}
+}
diff --git a/internal/port/sdlc_executor.go b/internal/port/sdlc_executor.go
new file mode 100644
index 0000000..d1de2e7
--- /dev/null
+++ b/internal/port/sdlc_executor.go
@@ -0,0 +1,93 @@
+package port
+
+import (
+	"context"
+
+	"github.com/orchard9/rdev/internal/sdlc"
+)
+
+// SDLCExecutor defines operations for executing SDLC commands in project pods.
+// The adapter runs `sdlc` CLI commands via kubectl exec and parses JSON output.
+type SDLCExecutor interface {
+	// GetState returns the global SDLC state for a project pod.
+	GetState(ctx context.Context, podName string) (*sdlc.State, error)
+
+	// GetNext returns the classifier's recommendation for the next action.
+	// If feature is empty, the classifier picks the most relevant feature.
+	GetNext(ctx context.Context, podName, feature string) (*sdlc.Classification, error)
+
+	// ListFeatures returns all features in the project.
+	ListFeatures(ctx context.Context, podName string) ([]*sdlc.Feature, error)
+
+	// GetFeature returns a single feature by slug.
+	GetFeature(ctx context.Context, podName, slug string) (*sdlc.Feature, error)
+
+	// CreateFeature creates a new feature with the given slug and title.
+	CreateFeature(ctx context.Context, podName, slug, title string) (*sdlc.Feature, error)
+
+	// TransitionFeature moves a feature to the specified phase.
+	TransitionFeature(ctx context.Context, podName, slug string, phase sdlc.FeaturePhase) error
+
+	// BlockFeature adds a blocker reason to a feature.
+	BlockFeature(ctx context.Context, podName, slug, reason string) error
+
+	// UnblockFeature removes all blockers from a feature.
+	UnblockFeature(ctx context.Context, podName, slug string) error
+
+	// DeleteFeature removes a feature entirely.
+	DeleteFeature(ctx context.Context, podName, slug string) error
+
+	// GetArtifactStatus returns artifact statuses for a feature.
+	GetArtifactStatus(ctx context.Context, podName, slug string) (map[sdlc.ArtifactType]*sdlc.Artifact, error)
+
+	// ApproveArtifact approves a feature artifact.
+	ApproveArtifact(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error
+
+	// RejectArtifact rejects a feature artifact.
+	RejectArtifact(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error
+
+	// ListTasks returns all tasks for a feature.
+	ListTasks(ctx context.Context, podName, slug string) ([]sdlc.Task, error)
+
+	// AddTask adds a new task to a feature.
+	AddTask(ctx context.Context, podName, slug, title string) (*sdlc.Task, error)
+
+	// StartTask marks a task as in-progress.
+	StartTask(ctx context.Context, podName, slug, taskID string) error
+
+	// CompleteTask marks a task as complete.
+	CompleteTask(ctx context.Context, podName, slug, taskID string) error
+
+	// BlockTask marks a task as blocked.
+	BlockTask(ctx context.Context, podName, slug, taskID string) error
+
+	// QueryBlocked returns all blocked features.
+	QueryBlocked(ctx context.Context, podName string) ([]BlockedInfo, error)
+
+	// QueryReady returns features ready for work.
+	QueryReady(ctx context.Context, podName string) ([]ReadyInfo, error)
+
+	// QueryNeedsApproval returns features awaiting approval.
+	QueryNeedsApproval(ctx context.Context, podName string) ([]ApprovalInfo, error)
+}
+
+// BlockedInfo describes a blocked feature (matches sdlc query --json output).
+type BlockedInfo struct {
+	Slug     string   `json:"slug"`
+	Phase    string   `json:"phase"`
+	Blockers []string `json:"blockers"`
+}
+
+// ReadyInfo describes a feature ready for work (matches sdlc query --json output).
+type ReadyInfo struct {
+	Slug   string `json:"slug"`
+	Phase  string `json:"phase"`
+	Action string `json:"action"`
+}
+
+// ApprovalInfo describes a feature awaiting approval (matches sdlc query --json output).
+type ApprovalInfo struct {
+	Slug    string `json:"slug"`
+	Phase   string `json:"phase"`
+	Message string `json:"message"`
+}
diff --git a/internal/sdlc/artifact.go b/internal/sdlc/artifact.go
new file mode 100644
index 0000000..7e1795e
--- /dev/null
+++ b/internal/sdlc/artifact.go
@@ -0,0 +1,63 @@
+package sdlc
+
+import "time"
+
+// Artifact tracks the status of a feature artifact.
+type Artifact struct {
+	Status     ArtifactStatus `yaml:"status" json:"status"`
+	Path       string         `yaml:"path" json:"path"`
+	ApprovedBy string         `yaml:"approved_by,omitempty" json:"approved_by,omitempty"`
+	ApprovedAt *time.Time     `yaml:"approved_at,omitempty" json:"approved_at,omitempty"`
+	RejectedBy string         `yaml:"rejected_by,omitempty" json:"rejected_by,omitempty"`
+	RejectedAt *time.Time     `yaml:"rejected_at,omitempty" json:"rejected_at,omitempty"`
+	Total      int            `yaml:"total,omitempty" json:"total,omitempty"`
+	Completed  int            `yaml:"completed,omitempty" json:"completed,omitempty"`
+	InProgress int            `yaml:"in_progress,omitempty" json:"in_progress,omitempty"`
+	Blocked    int            `yaml:"blocked,omitempty" json:"blocked,omitempty"`
+}
+
+// NewArtifact creates an artifact in pending status.
+func NewArtifact(artifactType ArtifactType) *Artifact {
+	return &Artifact{
+		Status: StatusPending,
+		Path:   ArtifactFilename(artifactType),
+	}
+}
+
+// Approve marks the artifact as approved.
+func (a *Artifact) Approve(by string) {
+	now := time.Now().UTC()
+	a.Status = StatusApproved
+	a.ApprovedBy = by
+	a.ApprovedAt = &now
+	a.RejectedBy = ""
+	a.RejectedAt = nil
+}
+
+// Reject marks the artifact as rejected.
+func (a *Artifact) Reject(by string) {
+	now := time.Now().UTC()
+	a.Status = StatusRejected
+	a.RejectedBy = by
+	a.RejectedAt = &now
+}
+
+// MarkDraft sets the artifact status to draft.
+func (a *Artifact) MarkDraft() {
+	a.Status = StatusDraft
+}
+
+// MarkPassed sets the artifact status to passed.
+func (a *Artifact) MarkPassed() {
+	a.Status = StatusPassed
+}
+
+// MarkFailed sets the artifact status to failed.
+func (a *Artifact) MarkFailed() {
+	a.Status = StatusFailed
+}
+
+// MarkNeedsFix sets the artifact status to needs_fix.
+func (a *Artifact) MarkNeedsFix() {
+	a.Status = StatusNeedsFix
+}
diff --git a/internal/sdlc/classifier.go b/internal/sdlc/classifier.go
new file mode 100644
index 0000000..b221083
--- /dev/null
+++ b/internal/sdlc/classifier.go
@@ -0,0 +1,91 @@
+package sdlc
+
+import "time"
+
+// Classification is the output of the classifier engine.
+type Classification struct {
+	Timestamp    time.Time    `json:"timestamp" yaml:"timestamp"`
+	Feature      string       `json:"feature" yaml:"feature"`
+	CurrentPhase FeaturePhase `json:"current_phase" yaml:"current_phase"`
+	RuleMatched  string       `json:"rule_matched" yaml:"rule_matched"`
+	Action       ActionType   `json:"action" yaml:"action"`
+	Message      string       `json:"message" yaml:"message"`
+	NextCommand  string       `json:"next_command,omitempty" yaml:"next_command,omitempty"`
+	OutputPath   string       `json:"output_path,omitempty" yaml:"output_path,omitempty"`
+	TransitionTo FeaturePhase `json:"transition_to,omitempty" yaml:"transition_to,omitempty"`
+	TaskID       string       `json:"task_id,omitempty" yaml:"task_id,omitempty"`
+}
+
+// EvalContext provides all the state needed for rule evaluation.
+type EvalContext struct {
+	State   *State
+	Feature *Feature
+	Config  *Config
+	Root    string
+}
+
+// Rule is a single classifier rule with a condition and resulting action.
+type Rule struct {
+	ID           string
+	Condition    func(ctx *EvalContext) bool
+	Action       ActionType
+	Message      func(ctx *EvalContext) string
+	NextCommand  func(ctx *EvalContext) string
+	OutputPath   func(ctx *EvalContext) string
+	TransitionTo FeaturePhase
+	TaskID       func(ctx *EvalContext) string
+}
+
+// Classifier evaluates rules in priority order, returning the first match.
+type Classifier struct {
+	rules []Rule
+}
+
+// NewClassifier creates a classifier with the default rules.
+func NewClassifier() *Classifier {
+	return &Classifier{rules: DefaultRules()}
+}
+
+// NewClassifierWithRules creates a classifier with custom rules.
+func NewClassifierWithRules(rules []Rule) *Classifier {
+	return &Classifier{rules: rules}
+}
+
+// Classify evaluates all rules against the context and returns the first match.
+func (c *Classifier) Classify(ctx *EvalContext) *Classification {
+	for _, rule := range c.rules {
+		if rule.Condition(ctx) {
+			cl := &Classification{
+				Timestamp:    time.Now().UTC(),
+				Feature:      ctx.Feature.Slug,
+				CurrentPhase: ctx.Feature.Phase,
+				RuleMatched:  rule.ID,
+				Action:       rule.Action,
+				TransitionTo: rule.TransitionTo,
+			}
+			if rule.Message != nil {
+				cl.Message = rule.Message(ctx)
+			}
+			if rule.NextCommand != nil {
+				cl.NextCommand = rule.NextCommand(ctx)
+			}
+			if rule.OutputPath != nil {
+				cl.OutputPath = rule.OutputPath(ctx)
+			}
+			if rule.TaskID != nil {
+				cl.TaskID = rule.TaskID(ctx)
+			}
+			return cl
+		}
+	}
+
+	// Default: nothing to do
+	return &Classification{
+		Timestamp:    time.Now().UTC(),
+		Feature:      ctx.Feature.Slug,
+		CurrentPhase: ctx.Feature.Phase,
+		RuleMatched:  "nothing-to-do",
+		Action:       ActionIdle,
+		Message:      "No actionable work found",
+	}
+}
diff --git a/internal/sdlc/classifier_test.go b/internal/sdlc/classifier_test.go
new file mode 100644
index 0000000..8190fe6
--- /dev/null
+++ b/internal/sdlc/classifier_test.go
@@ -0,0 +1,493 @@
+package sdlc
+
+import "testing"
+
+func makeTestFeature(phase FeaturePhase) *Feature {
+	f := &Feature{
+		Slug:  "auth",
+		Title: "Auth",
+		Phase: phase,
+		Artifacts: map[ArtifactType]*Artifact{
+			ArtifactSpec:      NewArtifact(ArtifactSpec),
+			ArtifactDesign:    NewArtifact(ArtifactDesign),
+			ArtifactTasks:     NewArtifact(ArtifactTasks),
+			ArtifactQAPlan:    NewArtifact(ArtifactQAPlan),
+			ArtifactReview:    NewArtifact(ArtifactReview),
+			ArtifactAudit:     NewArtifact(ArtifactAudit),
+			ArtifactQAResults: NewArtifact(ArtifactQAResults),
+		},
+	}
+	return f
+}
+
+func TestClassifyDraftNeedsSpec(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseDraft)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionCreateSpec {
+		t.Errorf("Action = %q, want CREATE_SPEC", cl.Action)
+	}
+	if cl.RuleMatched != "needs-spec" {
+		t.Errorf("RuleMatched = %q, want needs-spec", cl.RuleMatched)
+	}
+}
+
+func TestClassifyDraftSpecDraftNeedsApproval(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseDraft)
+	f.GetArtifact(ArtifactSpec).MarkDraft()
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionAwaitApproval {
+		t.Errorf("Action = %q, want AWAIT_APPROVAL", cl.Action)
+	}
+	if cl.RuleMatched != "spec-needs-approval" {
+		t.Errorf("RuleMatched = %q, want spec-needs-approval", cl.RuleMatched)
+	}
+}
+
+func TestClassifyDraftSpecApprovedTransition(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseDraft)
+	f.GetArtifact(ArtifactSpec).Approve("user")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhaseSpecified {
+		t.Errorf("TransitionTo = %q, want specified", cl.TransitionTo)
+	}
+}
+
+func TestClassifySpecifiedNeedsDesign(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseSpecified)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionCreateDesign {
+		t.Errorf("Action = %q, want CREATE_DESIGN", cl.Action)
+	}
+}
+
+func TestClassifySpecifiedNeedsTasks(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseSpecified)
+	f.GetArtifact(ArtifactDesign).Approve("user")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionCreateTasks {
+		t.Errorf("Action = %q, want CREATE_TASKS", cl.Action)
+	}
+}
+
+func TestClassifySpecifiedNeedsQAPlan(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseSpecified)
+	f.GetArtifact(ArtifactDesign).Approve("user")
+	f.GetArtifact(ArtifactTasks).Approve("user")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionCreateQAPlan {
+		t.Errorf("Action = %q, want CREATE_QA_PLAN", cl.Action)
+	}
+}
+
+func TestClassifySpecifiedPlanningComplete(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseSpecified)
+	f.GetArtifact(ArtifactDesign).Approve("user")
+	f.GetArtifact(ArtifactTasks).Approve("user")
+	f.GetArtifact(ArtifactQAPlan).Approve("user")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhasePlanned {
+		t.Errorf("TransitionTo = %q, want planned", cl.TransitionTo)
+	}
+}
+
+func TestClassifyPlannedTransitionsToReady(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhasePlanned)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhaseReady {
+		t.Errorf("TransitionTo = %q, want ready", cl.TransitionTo)
+	}
+}
+
+func TestClassifyImplementationNextTask(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseImplementation)
+	f.Tasks = AddTask(nil, "Task 1")
+	f.Tasks = AddTask(f.Tasks, "Task 2")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionImplementTask {
+		t.Errorf("Action = %q, want IMPLEMENT_TASK", cl.Action)
+	}
+	if cl.TaskID != "task-001" {
+		t.Errorf("TaskID = %q, want task-001", cl.TaskID)
+	}
+}
+
+func TestClassifyImplementationComplete(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseImplementation)
+	f.Tasks = AddTask(nil, "Task 1")
+	f.Tasks, _ = StartTask(f.Tasks, "task-001")
+	f.Tasks, _ = CompleteTask(f.Tasks, "task-001")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhaseReview {
+		t.Errorf("TransitionTo = %q, want review", cl.TransitionTo)
+	}
+}
+
+func TestClassifyReviewNeeded(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseReview)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionReviewCode {
+		t.Errorf("Action = %q, want REVIEW_CODE", cl.Action)
+	}
+}
+
+func TestClassifyReviewNeedsFix(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseReview)
+	f.GetArtifact(ArtifactReview).MarkNeedsFix()
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionFixReviewIssues {
+		t.Errorf("Action = %q, want FIX_REVIEW_ISSUES", cl.Action)
+	}
+}
+
+func TestClassifyReviewPassed(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseReview)
+	f.GetArtifact(ArtifactReview).MarkPassed()
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhaseAudit {
+		t.Errorf("TransitionTo = %q, want audit", cl.TransitionTo)
+	}
+}
+
+func TestClassifyAuditNeeded(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseAudit)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionAuditCode {
+		t.Errorf("Action = %q, want AUDIT_CODE", cl.Action)
+	}
+}
+
+func TestClassifyAuditPassed(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseAudit)
+	f.GetArtifact(ArtifactAudit).MarkPassed()
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhaseQA {
+		t.Errorf("TransitionTo = %q, want qa", cl.TransitionTo)
+	}
+}
+
+func TestClassifyQANeeded(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseQA)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionRunQA {
+		t.Errorf("Action = %q, want RUN_QA", cl.Action)
+	}
+}
+
+func TestClassifyQAPassed(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseQA)
+	f.GetArtifact(ArtifactQAResults).MarkPassed()
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionTransition {
+		t.Errorf("Action = %q, want TRANSITION", cl.Action)
+	}
+	if cl.TransitionTo != PhaseMerge {
+		t.Errorf("TransitionTo = %q, want merge", cl.TransitionTo)
+	}
+}
+
+func TestClassifyMerge(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseMerge)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionMergeFeature {
+		t.Errorf("Action = %q, want MERGE_FEATURE", cl.Action)
+	}
+}
+
+func TestClassifyArchive(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseReleased)
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionArchive {
+		t.Errorf("Action = %q, want ARCHIVE", cl.Action)
+	}
+}
+
+func TestClassifyBlocked(t *testing.T) {
+	c := NewClassifier()
+	f := makeTestFeature(PhaseDraft)
+	f.AddBlocker("depends on payments")
+
+	cl := c.Classify(&EvalContext{
+		State:   DefaultState("test"),
+		Feature: f,
+		Config:  DefaultConfig("test"),
+	})
+
+	if cl.Action != ActionBlocked {
+		t.Errorf("Action = %q, want BLOCKED", cl.Action)
+	}
+}
+
+// TestFullLifecycleClassification walks through the entire feature lifecycle.
+func TestFullLifecycleClassification(t *testing.T) {
+	c := NewClassifier()
+	cfg := DefaultConfig("test")
+	state := DefaultState("test")
+	f := makeTestFeature(PhaseDraft)
+
+	// Phase: Draft
+	// Step 1: needs spec
+	cl := c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionCreateSpec {
+		t.Fatalf("step1: Action = %q, want CREATE_SPEC", cl.Action)
+	}
+
+	// Step 2: spec created -> needs approval
+	f.GetArtifact(ArtifactSpec).MarkDraft()
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionAwaitApproval {
+		t.Fatalf("step2: Action = %q, want AWAIT_APPROVAL", cl.Action)
+	}
+
+	// Step 3: spec approved -> transition to specified
+	f.GetArtifact(ArtifactSpec).Approve("user")
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionTransition || cl.TransitionTo != PhaseSpecified {
+		t.Fatalf("step3: Action = %q/%q", cl.Action, cl.TransitionTo)
+	}
+
+	// Phase: Specified
+	f.Transition(PhaseSpecified)
+
+	// Step 4: needs design
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionCreateDesign {
+		t.Fatalf("step4: Action = %q, want CREATE_DESIGN", cl.Action)
+	}
+
+	// Step 5: design approved -> needs tasks
+	f.GetArtifact(ArtifactDesign).Approve("user")
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionCreateTasks {
+		t.Fatalf("step5: Action = %q, want CREATE_TASKS", cl.Action)
+	}
+
+	// Step 6: tasks approved -> needs qa plan
+	f.GetArtifact(ArtifactTasks).Approve("user")
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionCreateQAPlan {
+		t.Fatalf("step6: Action = %q, want CREATE_QA_PLAN", cl.Action)
+	}
+
+	// Step 7: qa plan approved -> transition to planned
+	f.GetArtifact(ArtifactQAPlan).Approve("user")
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionTransition || cl.TransitionTo != PhasePlanned {
+		t.Fatalf("step7: Action = %q/%q", cl.Action, cl.TransitionTo)
+	}
+
+	// Phase: Planned -> Ready -> Implementation
+	f.Transition(PhasePlanned)
+	f.Transition(PhaseReady)
+	f.Transition(PhaseImplementation)
+
+	// Add tasks
+	f.Tasks = AddTask(nil, "Create user model")
+	f.Tasks = AddTask(f.Tasks, "Add validation")
+
+	// Step 8: implement next task
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionImplementTask {
+		t.Fatalf("step8: Action = %q, want IMPLEMENT_TASK", cl.Action)
+	}
+
+	// Complete all tasks
+	f.Tasks, _ = StartTask(f.Tasks, "task-001")
+	f.Tasks, _ = CompleteTask(f.Tasks, "task-001")
+	f.Tasks, _ = StartTask(f.Tasks, "task-002")
+	f.Tasks, _ = CompleteTask(f.Tasks, "task-002")
+
+	// Step 9: implementation complete -> transition to review
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionTransition || cl.TransitionTo != PhaseReview {
+		t.Fatalf("step9: Action = %q/%q", cl.Action, cl.TransitionTo)
+	}
+
+	// Phase: Review
+	f.Transition(PhaseReview)
+	f.GetArtifact(ArtifactReview).MarkPassed()
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.TransitionTo != PhaseAudit {
+		t.Fatalf("review->audit: TransitionTo = %q", cl.TransitionTo)
+	}
+
+	// Phase: Audit
+	f.Transition(PhaseAudit)
+	f.GetArtifact(ArtifactAudit).MarkPassed()
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.TransitionTo != PhaseQA {
+		t.Fatalf("audit->qa: TransitionTo = %q", cl.TransitionTo)
+	}
+
+	// Phase: QA
+	f.Transition(PhaseQA)
+	f.GetArtifact(ArtifactQAResults).MarkPassed()
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.TransitionTo != PhaseMerge {
+		t.Fatalf("qa->merge: TransitionTo = %q", cl.TransitionTo)
+	}
+
+	// Phase: Merge
+	f.Transition(PhaseMerge)
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionMergeFeature {
+		t.Fatalf("merge: Action = %q, want MERGE_FEATURE", cl.Action)
+	}
+
+	// Phase: Released
+	f.Transition(PhaseReleased)
+	cl = c.Classify(&EvalContext{State: state, Feature: f, Config: cfg})
+	if cl.Action != ActionArchive {
+		t.Fatalf("released: Action = %q, want ARCHIVE", cl.Action)
+	}
+}
diff --git a/internal/sdlc/config.go b/internal/sdlc/config.go
new file mode 100644
index 0000000..3f1ce47
--- /dev/null
+++ b/internal/sdlc/config.go
@@ -0,0 +1,115 @@
+package sdlc
+
+import (
+	"fmt"
+	"os"
+	"slices"
+
+	"gopkg.in/yaml.v3"
+)
+
+// Config represents the project SDLC configuration in .sdlc/config.yaml.
+type Config struct {
+	Version    int              `yaml:"version" json:"version"`
+	Project    ProjectConfig    `yaml:"project" json:"project"`
+	Branches   BranchConfig     `yaml:"branches" json:"branches"`
+	Phases     PhaseConfig      `yaml:"phases" json:"phases"`
+	Compliance ComplianceConfig `yaml:"compliance" json:"compliance"`
+	Patterns   PatternsConfig   `yaml:"patterns,omitempty" json:"patterns,omitempty"` //nolint:omitzero
+}
+
+// ProjectConfig holds project-level settings.
+type ProjectConfig struct {
+	Name string `yaml:"name" json:"name"`
+	Type string `yaml:"type,omitempty" json:"type,omitempty"`
+}
+
+// BranchConfig defines branch naming conventions.
+type BranchConfig struct {
+	Main          string `yaml:"main" json:"main"`
+	FeaturePrefix string `yaml:"feature_prefix" json:"feature_prefix"`
+}
+
+// PhaseConfig defines which phases are enabled and what artifacts are required.
+type PhaseConfig struct {
+	Enabled           []FeaturePhase                  `yaml:"enabled" json:"enabled"`
+	RequiredArtifacts map[FeaturePhase][]ArtifactType `yaml:"required_artifacts" json:"required_artifacts"`
+}
+
+// ComplianceConfig defines approval and gate requirements.
+type ComplianceConfig struct {
+	RequireApprovals bool `yaml:"require_approvals" json:"require_approvals"`
+	RequireBranch    bool `yaml:"require_branch" json:"require_branch"`
+	RequireQA        bool `yaml:"require_qa" json:"require_qa"`
+}
+
+// PatternsConfig defines pattern enforcement.
+type PatternsConfig struct {
+	AutoEnforce []string `yaml:"auto_enforce,omitempty" json:"auto_enforce,omitempty"`
+}
+
+// LoadConfig reads and parses .sdlc/config.yaml from the given project root.
+func LoadConfig(root string) (*Config, error) {
+	path := ConfigPath(root)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrNotInitialized
+		}
+		return nil, fmt.Errorf("read config file: %w", err)
+	}
+
+	var c Config
+	if err := yaml.Unmarshal(data, &c); err != nil {
+		return nil, fmt.Errorf("parse config file: %w", err)
+	}
+	return &c, nil
+}
+
+// Save writes the config to .sdlc/config.yaml.
+func (c *Config) Save(root string) error {
+	data, err := yaml.Marshal(c)
+	if err != nil {
+		return fmt.Errorf("marshal config: %w", err)
+	}
+
+	path := ConfigPath(root)
+	if err := os.WriteFile(path, data, 0o644); err != nil {
+		return fmt.Errorf("write config file: %w", err)
+	}
+	return nil
+}
+
+// DefaultConfig returns a config with all phases enabled and standard requirements.
+func DefaultConfig(projectName string) *Config {
+	return &Config{
+		Version: 1,
+		Project: ProjectConfig{
+			Name: projectName,
+		},
+		Branches: BranchConfig{
+			Main:          "main",
+			FeaturePrefix: "feature/",
+		},
+		Phases: PhaseConfig{
+			Enabled: ValidPhases,
+			RequiredArtifacts: map[FeaturePhase][]ArtifactType{
+				PhaseSpecified: {ArtifactSpec},
+				PhasePlanned:   {ArtifactSpec, ArtifactDesign, ArtifactTasks, ArtifactQAPlan},
+				PhaseReview:    {ArtifactReview},
+				PhaseAudit:     {ArtifactAudit},
+				PhaseQA:        {ArtifactQAResults},
+			},
+		},
+		Compliance: ComplianceConfig{
+			RequireApprovals: true,
+			RequireBranch:    true,
+			RequireQA:        true,
+		},
+	}
+}
+
+// IsPhaseEnabled returns true if the phase is in the enabled list.
+func (c *Config) IsPhaseEnabled(phase FeaturePhase) bool {
+	return slices.Contains(c.Phases.Enabled, phase)
+}
diff --git a/internal/sdlc/config_test.go b/internal/sdlc/config_test.go
new file mode 100644
index 0000000..a929589
--- /dev/null
+++ b/internal/sdlc/config_test.go
@@ -0,0 +1,76 @@
+package sdlc
+
+import (
+	"os"
+	"testing"
+)
+
+func TestConfigRoundTrip(t *testing.T) {
+	root := t.TempDir()
+
+	if err := os.MkdirAll(SDLCRoot(root), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	original := DefaultConfig("test-project")
+
+	if err := original.Save(root); err != nil {
+		t.Fatalf("Save: %v", err)
+	}
+
+	loaded, err := LoadConfig(root)
+	if err != nil {
+		t.Fatalf("LoadConfig: %v", err)
+	}
+
+	if loaded.Version != 1 {
+		t.Errorf("Version = %d, want 1", loaded.Version)
+	}
+	if loaded.Project.Name != "test-project" {
+		t.Errorf("Project.Name = %q, want %q", loaded.Project.Name, "test-project")
+	}
+	if loaded.Branches.Main != "main" {
+		t.Errorf("Branches.Main = %q, want main", loaded.Branches.Main)
+	}
+	if loaded.Branches.FeaturePrefix != "feature/" {
+		t.Errorf("Branches.FeaturePrefix = %q, want feature/", loaded.Branches.FeaturePrefix)
+	}
+	if len(loaded.Phases.Enabled) != len(ValidPhases) {
+		t.Errorf("Phases.Enabled len = %d, want %d", len(loaded.Phases.Enabled), len(ValidPhases))
+	}
+}
+
+func TestDefaultConfigRequiredArtifacts(t *testing.T) {
+	c := DefaultConfig("test")
+
+	// specified phase requires spec
+	arts, ok := c.Phases.RequiredArtifacts[PhaseSpecified]
+	if !ok || len(arts) != 1 || arts[0] != ArtifactSpec {
+		t.Errorf("RequiredArtifacts[specified] = %v, want [spec]", arts)
+	}
+
+	// planned phase requires 4 artifacts
+	arts, ok = c.Phases.RequiredArtifacts[PhasePlanned]
+	if !ok || len(arts) != 4 {
+		t.Errorf("RequiredArtifacts[planned] len = %d, want 4", len(arts))
+	}
+}
+
+func TestIsPhaseEnabled(t *testing.T) {
+	c := DefaultConfig("test")
+
+	if !c.IsPhaseEnabled(PhaseDraft) {
+		t.Error("IsPhaseEnabled(draft) = false, want true")
+	}
+	if c.IsPhaseEnabled("bogus") {
+		t.Error("IsPhaseEnabled(bogus) = true, want false")
+	}
+}
+
+func TestLoadConfigNotInitialized(t *testing.T) {
+	root := t.TempDir()
+	_, err := LoadConfig(root)
+	if err != ErrNotInitialized {
+		t.Errorf("LoadConfig = %v, want ErrNotInitialized", err)
+	}
+}
diff --git a/internal/sdlc/errors.go b/internal/sdlc/errors.go
new file mode 100644
index 0000000..ea299cc
--- /dev/null
+++ b/internal/sdlc/errors.go
@@ -0,0 +1,16 @@
+package sdlc
+
+import "errors"
+
+var (
+	ErrNotInitialized    = errors.New("sdlc not initialized: run 'sdlc init'")
+	ErrFeatureNotFound   = errors.New("feature not found")
+	ErrFeatureExists     = errors.New("feature already exists")
+	ErrInvalidSlug       = errors.New("invalid slug: must be lowercase alphanumeric with hyphens")
+	ErrInvalidTransition = errors.New("invalid phase transition")
+	ErrInvalidPhase      = errors.New("invalid phase")
+	ErrInvalidArtifact   = errors.New("invalid artifact type")
+	ErrTaskNotFound      = errors.New("task not found")
+	ErrArtifactNotFound  = errors.New("artifact not found")
+	ErrNoFeatures        = errors.New("no features found")
+)
diff --git a/internal/sdlc/feature.go b/internal/sdlc/feature.go
new file mode 100644
index 0000000..164d3b0
--- /dev/null
+++ b/internal/sdlc/feature.go
@@ -0,0 +1,267 @@
+package sdlc
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+// Feature represents a feature under development, stored in manifest.yaml.
+type Feature struct {
+	Slug         string                     `yaml:"slug" json:"slug"`
+	Title        string                     `yaml:"title" json:"title"`
+	Created      time.Time                  `yaml:"created" json:"created"`
+	Branch       string                     `yaml:"branch,omitempty" json:"branch,omitempty"`
+	RoadmapRef   string                     `yaml:"roadmap_ref,omitempty" json:"roadmap_ref,omitempty"`
+	Phase        FeaturePhase               `yaml:"phase" json:"phase"`
+	PhaseHistory []PhaseTransition          `yaml:"phase_history" json:"phase_history"`
+	Artifacts    map[ArtifactType]*Artifact `yaml:"artifacts" json:"artifacts"`
+	Tasks        []Task                     `yaml:"tasks,omitempty" json:"tasks,omitempty"`
+	Blockers     []string                   `yaml:"blockers,omitempty" json:"blockers,omitempty"`
+	Dependencies Dependencies               `yaml:"dependencies,omitempty" json:"dependencies,omitempty"` //nolint:omitzero
+}
+
+// CreateFeature creates a new feature directory and manifest.
+func CreateFeature(root, slug, title string) (*Feature, error) {
+	if err := ValidateSlug(slug); err != nil {
+		return nil, err
+	}
+
+	dir := FeatureDir(root, slug)
+	if _, err := os.Stat(dir); err == nil {
+		return nil, ErrFeatureExists
+	}
+
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, fmt.Errorf("create feature directory: %w", err)
+	}
+
+	now := time.Now().UTC()
+	f := &Feature{
+		Slug:    slug,
+		Title:   title,
+		Created: now,
+		Phase:   PhaseDraft,
+		PhaseHistory: []PhaseTransition{
+			{Phase: PhaseDraft, Entered: now},
+		},
+		Artifacts: map[ArtifactType]*Artifact{
+			ArtifactSpec:      NewArtifact(ArtifactSpec),
+			ArtifactDesign:    NewArtifact(ArtifactDesign),
+			ArtifactTasks:     NewArtifact(ArtifactTasks),
+			ArtifactQAPlan:    NewArtifact(ArtifactQAPlan),
+			ArtifactReview:    NewArtifact(ArtifactReview),
+			ArtifactAudit:     NewArtifact(ArtifactAudit),
+			ArtifactQAResults: NewArtifact(ArtifactQAResults),
+		},
+	}
+
+	if err := f.Save(root); err != nil {
+		return nil, err
+	}
+	return f, nil
+}
+
+// LoadFeature reads a feature manifest from disk.
+func LoadFeature(root, slug string) (*Feature, error) {
+	path := ManifestPath(root, slug)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrFeatureNotFound
+		}
+		return nil, fmt.Errorf("read feature manifest: %w", err)
+	}
+
+	var f Feature
+	if err := yaml.Unmarshal(data, &f); err != nil {
+		return nil, fmt.Errorf("parse feature manifest: %w", err)
+	}
+	return &f, nil
+}
+
+// Save writes the feature manifest to disk.
+func (f *Feature) Save(root string) error {
+	data, err := yaml.Marshal(f)
+	if err != nil {
+		return fmt.Errorf("marshal feature manifest: %w", err)
+	}
+
+	path := ManifestPath(root, f.Slug)
+	if err := os.WriteFile(path, data, 0o644); err != nil {
+		return fmt.Errorf("write feature manifest: %w", err)
+	}
+	return nil
+}
+
+// ListFeatures returns all features found in .sdlc/features/.
+func ListFeatures(root string) ([]*Feature, error) {
+	dir := FeaturesDirPath(root)
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrNotInitialized
+		}
+		return nil, fmt.Errorf("read features directory: %w", err)
+	}
+
+	var features []*Feature
+	for _, entry := range entries {
+		if !entry.IsDir() {
+			continue
+		}
+		manifestPath := filepath.Join(dir, entry.Name(), ManifestFile)
+		if _, err := os.Stat(manifestPath); os.IsNotExist(err) {
+			continue
+		}
+		f, err := LoadFeature(root, entry.Name())
+		if err != nil {
+			continue
+		}
+		features = append(features, f)
+	}
+	return features, nil
+}
+
+// CanTransitionTo checks if the feature can move to the target phase.
+// It validates ordering, config allowances, required artifacts, and blockers.
+func (f *Feature) CanTransitionTo(target FeaturePhase, cfg *Config) error {
+	if !IsValidPhase(target) {
+		return fmt.Errorf("%w: %s is not a valid phase", ErrInvalidPhase, target)
+	}
+
+	if cfg != nil && !cfg.IsPhaseEnabled(target) {
+		return fmt.Errorf("%w: phase %s is not enabled", ErrInvalidTransition, target)
+	}
+
+	currentIdx := PhaseIndex(f.Phase)
+	targetIdx := PhaseIndex(target)
+
+	if targetIdx <= currentIdx {
+		return fmt.Errorf("%w: cannot move from %s to %s (backward)", ErrInvalidTransition, f.Phase, target)
+	}
+
+	// Only allow moving to the next phase (no skipping)
+	if targetIdx != currentIdx+1 {
+		return fmt.Errorf("%w: cannot skip from %s to %s", ErrInvalidTransition, f.Phase, target)
+	}
+
+	// Check required artifacts for the target phase are approved/passed
+	if cfg != nil {
+		required, ok := cfg.Phases.RequiredArtifacts[target]
+		if ok {
+			for _, artType := range required {
+				art, exists := f.Artifacts[artType]
+				if !exists {
+					return fmt.Errorf("%w: missing required artifact %s to enter phase %s", ErrInvalidTransition, artType, target)
+				}
+				if art.Status != StatusApproved && art.Status != StatusPassed {
+					return fmt.Errorf("%w: artifact %s is %s, must be approved or passed to enter %s", ErrInvalidTransition, artType, art.Status, target)
+				}
+			}
+		}
+	}
+
+	// Check no blockers
+	if len(f.Blockers) > 0 {
+		return fmt.Errorf("%w: feature has %d blocker(s)", ErrInvalidTransition, len(f.Blockers))
+	}
+
+	return nil
+}
+
+// Transition moves the feature to the target phase, recording history.
+func (f *Feature) Transition(target FeaturePhase) error {
+	now := time.Now().UTC()
+
+	// Close the current phase history entry
+	if len(f.PhaseHistory) > 0 {
+		f.PhaseHistory[len(f.PhaseHistory)-1].Exited = &now
+	}
+
+	f.Phase = target
+	f.PhaseHistory = append(f.PhaseHistory, PhaseTransition{
+		Phase:   target,
+		Entered: now,
+	})
+
+	return nil
+}
+
+// AddBlocker adds a blocker reason.
+func (f *Feature) AddBlocker(reason string) {
+	f.Blockers = append(f.Blockers, reason)
+}
+
+// ClearBlockers removes all blockers.
+func (f *Feature) ClearBlockers() {
+	f.Blockers = nil
+}
+
+// IsBlocked returns true if the feature has any blockers.
+func (f *Feature) IsBlocked() bool {
+	return len(f.Blockers) > 0
+}
+
+// GetArtifact returns the artifact by type, or nil.
+func (f *Feature) GetArtifact(t ArtifactType) *Artifact {
+	if f.Artifacts == nil {
+		return nil
+	}
+	return f.Artifacts[t]
+}
+
+// SetArtifact sets or creates an artifact entry.
+func (f *Feature) SetArtifact(t ArtifactType, a *Artifact) {
+	if f.Artifacts == nil {
+		f.Artifacts = make(map[ArtifactType]*Artifact)
+	}
+	f.Artifacts[t] = a
+}
+
+// ArtifactFileExists checks if the artifact file exists on disk.
+func (f *Feature) ArtifactFileExists(root string, artType ArtifactType) bool {
+	path := ArtifactPath(root, f.Slug, artType)
+	if path == "" {
+		return false
+	}
+	_, err := os.Stat(path)
+	return err == nil
+}
+
+// DeleteFeature removes a feature directory and all contents.
+func DeleteFeature(root, slug string) error {
+	dir := FeatureDir(root, slug)
+	if _, err := os.Stat(dir); os.IsNotExist(err) {
+		return ErrFeatureNotFound
+	}
+	return os.RemoveAll(dir)
+}
+
+// ArchiveFeature moves a feature from features/ to archives/.
+func ArchiveFeature(root, slug string) error {
+	src := FeatureDir(root, slug)
+	if _, err := os.Stat(src); os.IsNotExist(err) {
+		return ErrFeatureNotFound
+	}
+
+	dst := filepath.Join(SDLCRoot(root), ArchivesDir, slug)
+	if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+		return fmt.Errorf("create archives directory: %w", err)
+	}
+	return os.Rename(src, dst)
+}
+
+// UpdateTaskSummary refreshes the tasks artifact with current counts.
+func (f *Feature) UpdateTaskSummary() {
+	summary := SummarizeTasks(f.Tasks)
+	if art := f.GetArtifact(ArtifactTasks); art != nil {
+		art.Total = summary.Total
+		art.Completed = summary.Completed
+		art.InProgress = summary.InProgress
+		art.Blocked = summary.Blocked
+	}
+}
diff --git a/internal/sdlc/feature_test.go b/internal/sdlc/feature_test.go
new file mode 100644
index 0000000..ea6d37b
--- /dev/null
+++ b/internal/sdlc/feature_test.go
@@ -0,0 +1,313 @@
+package sdlc
+
+import (
+	"errors"
+	"testing"
+)
+
+func setupInitializedRoot(t *testing.T) string {
+	t.Helper()
+	root := t.TempDir()
+	if err := Init(root, "test-project"); err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+	return root
+}
+
+func TestCreateFeature(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	f, err := CreateFeature(root, "auth", "User Authentication")
+	if err != nil {
+		t.Fatalf("CreateFeature: %v", err)
+	}
+
+	if f.Slug != "auth" {
+		t.Errorf("Slug = %q, want auth", f.Slug)
+	}
+	if f.Title != "User Authentication" {
+		t.Errorf("Title = %q, want User Authentication", f.Title)
+	}
+	if f.Phase != PhaseDraft {
+		t.Errorf("Phase = %q, want draft", f.Phase)
+	}
+	if len(f.PhaseHistory) != 1 {
+		t.Errorf("PhaseHistory len = %d, want 1", len(f.PhaseHistory))
+	}
+	if len(f.Artifacts) != 7 {
+		t.Errorf("Artifacts len = %d, want 7", len(f.Artifacts))
+	}
+}
+
+func TestCreateFeatureDuplicate(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	if _, err := CreateFeature(root, "auth", "Auth"); err != nil {
+		t.Fatalf("CreateFeature: %v", err)
+	}
+
+	_, err := CreateFeature(root, "auth", "Auth Again")
+	if !errors.Is(err, ErrFeatureExists) {
+		t.Errorf("err = %v, want ErrFeatureExists", err)
+	}
+}
+
+func TestCreateFeatureInvalidSlug(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	_, err := CreateFeature(root, "INVALID", "Bad Slug")
+	if !errors.Is(err, ErrInvalidSlug) {
+		t.Errorf("err = %v, want ErrInvalidSlug", err)
+	}
+}
+
+func TestLoadFeature(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	if _, err := CreateFeature(root, "auth", "Auth"); err != nil {
+		t.Fatalf("CreateFeature: %v", err)
+	}
+
+	loaded, err := LoadFeature(root, "auth")
+	if err != nil {
+		t.Fatalf("LoadFeature: %v", err)
+	}
+
+	if loaded.Slug != "auth" {
+		t.Errorf("Slug = %q, want auth", loaded.Slug)
+	}
+	if loaded.Phase != PhaseDraft {
+		t.Errorf("Phase = %q, want draft", loaded.Phase)
+	}
+}
+
+func TestLoadFeatureNotFound(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	_, err := LoadFeature(root, "nonexistent")
+	if !errors.Is(err, ErrFeatureNotFound) {
+		t.Errorf("err = %v, want ErrFeatureNotFound", err)
+	}
+}
+
+func TestListFeatures(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	if _, err := CreateFeature(root, "auth", "Auth"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := CreateFeature(root, "payments", "Payments"); err != nil {
+		t.Fatal(err)
+	}
+
+	features, err := ListFeatures(root)
+	if err != nil {
+		t.Fatalf("ListFeatures: %v", err)
+	}
+	if len(features) != 2 {
+		t.Errorf("ListFeatures len = %d, want 2", len(features))
+	}
+}
+
+func TestCanTransitionTo(t *testing.T) {
+	cfg := DefaultConfig("test")
+	f := &Feature{
+		Phase: PhaseDraft,
+		Artifacts: map[ArtifactType]*Artifact{
+			ArtifactSpec: {Status: StatusApproved},
+		},
+	}
+
+	// Valid: draft -> specified (spec is approved)
+	if err := f.CanTransitionTo(PhaseSpecified, cfg); err != nil {
+		t.Errorf("CanTransitionTo(specified) = %v, want nil", err)
+	}
+
+	// Invalid: draft -> planned (skip)
+	if err := f.CanTransitionTo(PhasePlanned, cfg); err == nil {
+		t.Error("CanTransitionTo(planned) = nil, want error (skip)")
+	}
+
+	// Invalid: draft -> draft (backward)
+	if err := f.CanTransitionTo(PhaseDraft, cfg); err == nil {
+		t.Error("CanTransitionTo(draft) = nil, want error (backward)")
+	}
+
+	// Invalid phase
+	if err := f.CanTransitionTo("bogus", cfg); err == nil {
+		t.Error("CanTransitionTo(bogus) = nil, want error")
+	}
+
+	// Without config, artifact checks are skipped
+	bare := &Feature{Phase: PhaseDraft}
+	if err := bare.CanTransitionTo(PhaseSpecified, nil); err != nil {
+		t.Errorf("CanTransitionTo(specified) without config = %v, want nil", err)
+	}
+}
+
+func TestTransition(t *testing.T) {
+	f := &Feature{
+		Phase: PhaseDraft,
+		PhaseHistory: []PhaseTransition{
+			{Phase: PhaseDraft},
+		},
+	}
+
+	if err := f.Transition(PhaseSpecified); err != nil {
+		t.Fatalf("Transition: %v", err)
+	}
+
+	if f.Phase != PhaseSpecified {
+		t.Errorf("Phase = %q, want specified", f.Phase)
+	}
+	if len(f.PhaseHistory) != 2 {
+		t.Fatalf("PhaseHistory len = %d, want 2", len(f.PhaseHistory))
+	}
+	if f.PhaseHistory[0].Exited == nil {
+		t.Error("PhaseHistory[0].Exited is nil, want set")
+	}
+	if f.PhaseHistory[1].Phase != PhaseSpecified {
+		t.Errorf("PhaseHistory[1].Phase = %q, want specified", f.PhaseHistory[1].Phase)
+	}
+}
+
+func TestFeatureManifestRoundTrip(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	f, err := CreateFeature(root, "auth", "Auth")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Modify and save
+	f.Branch = "feature/auth"
+	if err := f.Transition(PhaseSpecified); err != nil {
+		t.Fatal(err)
+	}
+	f.GetArtifact(ArtifactSpec).Approve("user")
+	f.Tasks = AddTask(nil, "Create user model")
+	f.UpdateTaskSummary()
+
+	if err := f.Save(root); err != nil {
+		t.Fatalf("Save: %v", err)
+	}
+
+	loaded, err := LoadFeature(root, "auth")
+	if err != nil {
+		t.Fatalf("LoadFeature: %v", err)
+	}
+
+	if loaded.Branch != "feature/auth" {
+		t.Errorf("Branch = %q, want feature/auth", loaded.Branch)
+	}
+	if loaded.Phase != PhaseSpecified {
+		t.Errorf("Phase = %q, want specified", loaded.Phase)
+	}
+	if loaded.GetArtifact(ArtifactSpec).Status != StatusApproved {
+		t.Errorf("Spec status = %q, want approved", loaded.GetArtifact(ArtifactSpec).Status)
+	}
+	if len(loaded.Tasks) != 1 {
+		t.Errorf("Tasks len = %d, want 1", len(loaded.Tasks))
+	}
+}
+
+func TestCanTransitionToRequiredArtifacts(t *testing.T) {
+	cfg := DefaultConfig("test")
+
+	// draft -> specified requires spec to be approved
+	f := &Feature{
+		Phase: PhaseDraft,
+		Artifacts: map[ArtifactType]*Artifact{
+			ArtifactSpec: {Status: StatusPending},
+		},
+	}
+
+	err := f.CanTransitionTo(PhaseSpecified, cfg)
+	if err == nil {
+		t.Error("CanTransitionTo(specified) should fail with unapproved spec")
+	}
+
+	// Approve spec - now draft -> specified should work
+	f.Artifacts[ArtifactSpec].Approve("user")
+	err = f.CanTransitionTo(PhaseSpecified, cfg)
+	if err != nil {
+		t.Errorf("CanTransitionTo(specified) with approved spec: %v", err)
+	}
+
+	// specified -> planned requires spec, design, tasks, qa_plan
+	f.Phase = PhaseSpecified
+	err = f.CanTransitionTo(PhasePlanned, cfg)
+	if err == nil {
+		t.Error("CanTransitionTo(planned) should fail with missing design/tasks/qa_plan")
+	}
+}
+
+func TestCanTransitionToBlockersPrevent(t *testing.T) {
+	cfg := DefaultConfig("test")
+
+	f := &Feature{
+		Phase:    PhaseDraft,
+		Blockers: []string{"dependency on payments"},
+	}
+
+	err := f.CanTransitionTo(PhaseSpecified, cfg)
+	if err == nil {
+		t.Error("CanTransitionTo should fail when feature has blockers")
+	}
+}
+
+func TestDeleteFeature(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	if _, err := CreateFeature(root, "auth", "Auth"); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := DeleteFeature(root, "auth"); err != nil {
+		t.Fatalf("DeleteFeature: %v", err)
+	}
+
+	_, err := LoadFeature(root, "auth")
+	if err != ErrFeatureNotFound {
+		t.Errorf("LoadFeature after delete: %v, want ErrFeatureNotFound", err)
+	}
+}
+
+func TestDeleteFeatureNotFound(t *testing.T) {
+	root := setupInitializedRoot(t)
+	if err := DeleteFeature(root, "nonexistent"); err != ErrFeatureNotFound {
+		t.Errorf("DeleteFeature = %v, want ErrFeatureNotFound", err)
+	}
+}
+
+func TestArtifactFileExists(t *testing.T) {
+	root := setupInitializedRoot(t)
+
+	f, err := CreateFeature(root, "auth", "Auth")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// No spec file exists yet
+	if f.ArtifactFileExists(root, ArtifactSpec) {
+		t.Error("ArtifactFileExists(spec) = true before file creation")
+	}
+}
+
+func TestBlockers(t *testing.T) {
+	f := &Feature{}
+
+	if f.IsBlocked() {
+		t.Error("IsBlocked = true, want false")
+	}
+
+	f.AddBlocker("dependency on auth")
+	if !f.IsBlocked() {
+		t.Error("IsBlocked = false, want true")
+	}
+
+	f.ClearBlockers()
+	if f.IsBlocked() {
+		t.Error("IsBlocked = true after clear, want false")
+	}
+}
diff --git a/internal/sdlc/history.go b/internal/sdlc/history.go
new file mode 100644
index 0000000..119d786
--- /dev/null
+++ b/internal/sdlc/history.go
@@ -0,0 +1,44 @@
+package sdlc
+
+import "time"
+
+// HistoryEntry records a single action taken in the SDLC lifecycle.
+type HistoryEntry struct {
+	Timestamp time.Time `yaml:"timestamp" json:"timestamp"`
+	Action    string    `yaml:"action" json:"action"`
+	Feature   string    `yaml:"feature,omitempty" json:"feature,omitempty"`
+	Actor     string    `yaml:"actor" json:"actor"`
+	Result    string    `yaml:"result,omitempty" json:"result,omitempty"`
+	Output    string    `yaml:"output,omitempty" json:"output,omitempty"`
+	FromPhase string    `yaml:"from_phase,omitempty" json:"from_phase,omitempty"`
+	ToPhase   string    `yaml:"to_phase,omitempty" json:"to_phase,omitempty"`
+}
+
+// BlockedItem represents something that is blocked in the SDLC.
+type BlockedItem struct {
+	Type   string `yaml:"type" json:"type"`
+	Slug   string `yaml:"slug" json:"slug"`
+	Reason string `yaml:"reason" json:"reason"`
+	Since  string `yaml:"since,omitempty" json:"since,omitempty"`
+	RuleID string `yaml:"rule_id,omitempty" json:"rule_id,omitempty"`
+}
+
+// ActiveFeature tracks a feature in active_work.
+type ActiveFeature struct {
+	Slug   string       `yaml:"slug" json:"slug"`
+	Branch string       `yaml:"branch,omitempty" json:"branch,omitempty"`
+	Phase  FeaturePhase `yaml:"phase" json:"phase"`
+}
+
+// ActiveWork tracks all active items.
+type ActiveWork struct {
+	Features []ActiveFeature `yaml:"features" json:"features"`
+	Patterns []string        `yaml:"patterns,omitempty" json:"patterns,omitempty"`
+	Audits   []string        `yaml:"audits,omitempty" json:"audits,omitempty"`
+}
+
+// ProjectState holds project-level metadata.
+type ProjectState struct {
+	Name           string `yaml:"name" json:"name"`
+	CurrentRoadmap string `yaml:"current_roadmap,omitempty" json:"current_roadmap,omitempty"`
+}
diff --git a/internal/sdlc/init.go b/internal/sdlc/init.go
new file mode 100644
index 0000000..9cab4dd
--- /dev/null
+++ b/internal/sdlc/init.go
@@ -0,0 +1,45 @@
+package sdlc
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// Init creates the .sdlc/ directory structure and default files.
+func Init(root, projectName string) error {
+	sdlcRoot := SDLCRoot(root)
+
+	// Check if already initialized
+	if _, err := os.Stat(sdlcRoot); err == nil {
+		return fmt.Errorf("already initialized: %s exists", sdlcRoot)
+	}
+
+	// Create .sdlc/ and all subdirectories
+	for _, dir := range SubDirs() {
+		dirPath := filepath.Join(sdlcRoot, dir)
+		if err := os.MkdirAll(dirPath, 0o755); err != nil {
+			return fmt.Errorf("create directory %s: %w", dir, err)
+		}
+	}
+
+	// Write default state
+	state := DefaultState(projectName)
+	if err := state.Save(root); err != nil {
+		return fmt.Errorf("write default state: %w", err)
+	}
+
+	// Write default config
+	config := DefaultConfig(projectName)
+	if err := config.Save(root); err != nil {
+		return fmt.Errorf("write default config: %w", err)
+	}
+
+	return nil
+}
+
+// IsInitialized returns true if the .sdlc/ directory exists.
+func IsInitialized(root string) bool {
+	info, err := os.Stat(SDLCRoot(root))
+	return err == nil && info.IsDir()
+}
diff --git a/internal/sdlc/init_test.go b/internal/sdlc/init_test.go
new file mode 100644
index 0000000..32a2417
--- /dev/null
+++ b/internal/sdlc/init_test.go
@@ -0,0 +1,88 @@
+package sdlc
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestInit(t *testing.T) {
+	root := t.TempDir()
+
+	if err := Init(root, "test-project"); err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	// Verify .sdlc directory exists
+	sdlcRoot := SDLCRoot(root)
+	info, err := os.Stat(sdlcRoot)
+	if err != nil {
+		t.Fatalf("stat .sdlc: %v", err)
+	}
+	if !info.IsDir() {
+		t.Fatal(".sdlc is not a directory")
+	}
+
+	// Verify all subdirectories exist
+	for _, dir := range SubDirs() {
+		dirPath := filepath.Join(sdlcRoot, dir)
+		info, err := os.Stat(dirPath)
+		if err != nil {
+			t.Errorf("stat %s: %v", dir, err)
+			continue
+		}
+		if !info.IsDir() {
+			t.Errorf("%s is not a directory", dir)
+		}
+	}
+
+	// Verify state.yaml
+	state, err := LoadState(root)
+	if err != nil {
+		t.Fatalf("LoadState: %v", err)
+	}
+	if state.Version != 1 {
+		t.Errorf("state.Version = %d, want 1", state.Version)
+	}
+	if state.Project.Name != "test-project" {
+		t.Errorf("state.Project.Name = %q, want test-project", state.Project.Name)
+	}
+
+	// Verify config.yaml
+	config, err := LoadConfig(root)
+	if err != nil {
+		t.Fatalf("LoadConfig: %v", err)
+	}
+	if config.Project.Name != "test-project" {
+		t.Errorf("config.Project.Name = %q, want test-project", config.Project.Name)
+	}
+}
+
+func TestInitAlreadyInitialized(t *testing.T) {
+	root := t.TempDir()
+
+	if err := Init(root, "test"); err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	err := Init(root, "test")
+	if err == nil {
+		t.Fatal("Init should fail when already initialized")
+	}
+}
+
+func TestIsInitialized(t *testing.T) {
+	root := t.TempDir()
+
+	if IsInitialized(root) {
+		t.Error("IsInitialized = true before init")
+	}
+
+	if err := Init(root, "test"); err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	if !IsInitialized(root) {
+		t.Error("IsInitialized = false after init")
+	}
+}
diff --git a/internal/sdlc/paths.go b/internal/sdlc/paths.go
new file mode 100644
index 0000000..b669ecd
--- /dev/null
+++ b/internal/sdlc/paths.go
@@ -0,0 +1,99 @@
+package sdlc
+
+import (
+	"path/filepath"
+	"regexp"
+)
+
+const (
+	// SDLCDir is the root directory name for SDLC state.
+	SDLCDir = ".sdlc"
+
+	// StateFile is the filename for global state.
+	StateFile = "state.yaml"
+
+	// ConfigFile is the filename for project config.
+	ConfigFile = "config.yaml"
+
+	// FeaturesDir holds per-feature subdirectories.
+	FeaturesDir = "features"
+
+	// PatternsDir holds pattern definitions.
+	PatternsDir = "patterns"
+
+	// AuditsDir holds audit reports.
+	AuditsDir = "audits"
+
+	// BranchesDir holds branch tracking files.
+	BranchesDir = "branches"
+
+	// ArchivesDir holds archived (released) features.
+	ArchivesDir = "archives"
+
+	// RoadmapDir holds roadmap documents.
+	RoadmapDir = "roadmap"
+
+	// ManifestFile is the per-feature metadata file.
+	ManifestFile = "manifest.yaml"
+)
+
+var slugPattern = regexp.MustCompile(`^[a-z][a-z0-9-]*$`)
+
+// ValidateSlug returns nil if the slug is valid, ErrInvalidSlug otherwise.
+func ValidateSlug(slug string) error {
+	if slug == "" || len(slug) > 64 || !slugPattern.MatchString(slug) {
+		return ErrInvalidSlug
+	}
+	return nil
+}
+
+// SDLCRoot returns the .sdlc directory path within a project root.
+func SDLCRoot(root string) string {
+	return filepath.Join(root, SDLCDir)
+}
+
+// StatePath returns the path to state.yaml.
+func StatePath(root string) string {
+	return filepath.Join(root, SDLCDir, StateFile)
+}
+
+// ConfigPath returns the path to config.yaml.
+func ConfigPath(root string) string {
+	return filepath.Join(root, SDLCDir, ConfigFile)
+}
+
+// FeaturesDirPath returns the features/ directory path.
+func FeaturesDirPath(root string) string {
+	return filepath.Join(root, SDLCDir, FeaturesDir)
+}
+
+// FeatureDir returns the directory for a specific feature.
+func FeatureDir(root, slug string) string {
+	return filepath.Join(root, SDLCDir, FeaturesDir, slug)
+}
+
+// ManifestPath returns the manifest.yaml path for a feature.
+func ManifestPath(root, slug string) string {
+	return filepath.Join(root, SDLCDir, FeaturesDir, slug, ManifestFile)
+}
+
+// ArtifactPath returns the file path for a feature artifact.
+func ArtifactPath(root, slug string, artifactType ArtifactType) string {
+	filename := ArtifactFilename(artifactType)
+	if filename == "" {
+		return ""
+	}
+	return filepath.Join(root, SDLCDir, FeaturesDir, slug, filename)
+}
+
+// SubDirs returns all subdirectories that sdlc init creates.
+func SubDirs() []string {
+	return []string{
+		FeaturesDir,
+		PatternsDir,
+		AuditsDir,
+		BranchesDir,
+		ArchivesDir,
+		RoadmapDir,
+	}
+}
diff --git a/internal/sdlc/paths_test.go b/internal/sdlc/paths_test.go
new file mode 100644
index 0000000..265359d
--- /dev/null
+++ b/internal/sdlc/paths_test.go
@@ -0,0 +1,114 @@
+package sdlc
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestStatePath(t *testing.T) {
+	got := StatePath("/project")
+	want := filepath.Join("/project", ".sdlc", "state.yaml")
+	if got != want {
+		t.Errorf("StatePath = %q, want %q", got, want)
+	}
+}
+
+func TestConfigPath(t *testing.T) {
+	got := ConfigPath("/project")
+	want := filepath.Join("/project", ".sdlc", "config.yaml")
+	if got != want {
+		t.Errorf("ConfigPath = %q, want %q", got, want)
+	}
+}
+
+func TestFeatureDir(t *testing.T) {
+	got := FeatureDir("/project", "auth")
+	want := filepath.Join("/project", ".sdlc", "features", "auth")
+	if got != want {
+		t.Errorf("FeatureDir = %q, want %q", got, want)
+	}
+}
+
+func TestManifestPath(t *testing.T) {
+	got := ManifestPath("/project", "auth")
+	want := filepath.Join("/project", ".sdlc", "features", "auth", "manifest.yaml")
+	if got != want {
+		t.Errorf("ManifestPath = %q, want %q", got, want)
+	}
+}
+
+func TestArtifactPath(t *testing.T) {
+	tests := []struct {
+		artifact ArtifactType
+		wantFile string
+	}{
+		{ArtifactSpec, "spec.md"},
+		{ArtifactDesign, "design.md"},
+		{ArtifactTasks, "tasks.md"},
+		{ArtifactQAPlan, "qa-plan.md"},
+		{ArtifactReview, "review.md"},
+		{ArtifactAudit, "audit.md"},
+		{ArtifactQAResults, "qa-results.md"},
+	}
+
+	for _, tt := range tests {
+		got := ArtifactPath("/project", "auth", tt.artifact)
+		want := filepath.Join("/project", ".sdlc", "features", "auth", tt.wantFile)
+		if got != want {
+			t.Errorf("ArtifactPath(%q) = %q, want %q", tt.artifact, got, want)
+		}
+	}
+}
+
+func TestArtifactPathInvalid(t *testing.T) {
+	got := ArtifactPath("/project", "auth", ArtifactType("bogus"))
+	if got != "" {
+		t.Errorf("ArtifactPath(bogus) = %q, want empty", got)
+	}
+}
+
+func TestValidateSlug(t *testing.T) {
+	valid := []string{"auth", "user-auth", "a1", "my-feature-2"}
+	for _, s := range valid {
+		if err := ValidateSlug(s); err != nil {
+			t.Errorf("ValidateSlug(%q) = %v, want nil", s, err)
+		}
+	}
+
+	invalid := []string{"", "Auth", "UPPER", "123start", "has spaces", "has_underscores", "-leading"}
+	for _, s := range invalid {
+		if err := ValidateSlug(s); err == nil {
+			t.Errorf("ValidateSlug(%q) = nil, want error", s)
+		}
+	}
+}
+
+func TestPhaseIndex(t *testing.T) {
+	if i := PhaseIndex(PhaseDraft); i != 0 {
+		t.Errorf("PhaseIndex(draft) = %d, want 0", i)
+	}
+	if i := PhaseIndex(PhaseReleased); i != 9 {
+		t.Errorf("PhaseIndex(released) = %d, want 9", i)
+	}
+	if i := PhaseIndex("bogus"); i != -1 {
+		t.Errorf("PhaseIndex(bogus) = %d, want -1", i)
+	}
+}
+
+func TestIsValidPhase(t *testing.T) {
+	if !IsValidPhase(PhaseDraft) {
+		t.Error("IsValidPhase(draft) = false, want true")
+	}
+	if IsValidPhase("bogus") {
+		t.Error("IsValidPhase(bogus) = true, want false")
+	}
+}
+
+func TestIsValidArtifactType(t *testing.T) {
+	if !IsValidArtifactType(ArtifactSpec) {
+		t.Error("IsValidArtifactType(spec) = false, want true")
+	}
+	if IsValidArtifactType("bogus") {
+		t.Error("IsValidArtifactType(bogus) = true, want false")
+	}
+}
diff --git a/internal/sdlc/rules.go b/internal/sdlc/rules.go
new file mode 100644
index 0000000..b6895ba
--- /dev/null
+++ b/internal/sdlc/rules.go
@@ -0,0 +1,478 @@
+package sdlc
+
+import (
+	"fmt"
+	"strings"
+)
+
+// DefaultRules returns all classifier rules in priority order.
+// First matching rule wins.
+func DefaultRules() []Rule {
+	return []Rule{
+		blockedDependencyRule(),
+		needsSpecRule(),
+		specNeedsApprovalRule(),
+		specApprovedRule(),
+		needsDesignRule(),
+		designNeedsApprovalRule(),
+		needsTasksRule(),
+		tasksNeedApprovalRule(),
+		needsQAPlanRule(),
+		qaPlanNeedsApprovalRule(),
+		planningCompleteRule(),
+		readyToImplementRule(),
+		implementNextTaskRule(),
+		implementationCompleteRule(),
+		needsReviewRule(),
+		reviewHasIssuesRule(),
+		reviewPassedRule(),
+		needsAuditRule(),
+		auditHasIssuesRule(),
+		auditPassedRule(),
+		needsQARule(),
+		qaHasFailuresRule(),
+		qaPassedRule(),
+		needsMergeRule(),
+		archiveFeatureRule(),
+	}
+}
+
+func blockedDependencyRule() Rule {
+	return Rule{
+		ID: "blocked-dependency",
+		Condition: func(ctx *EvalContext) bool {
+			return ctx.Feature.IsBlocked()
+		},
+		Action: ActionBlocked,
+		Message: func(ctx *EvalContext) string {
+			return fmt.Sprintf("Feature blocked by: %s", strings.Join(ctx.Feature.Blockers, ", "))
+		},
+	}
+}
+
+func needsSpecRule() Rule {
+	return Rule{
+		ID: "needs-spec",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseDraft {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactSpec)
+			return art == nil || art.Status == StatusPending
+		},
+		Action: ActionCreateSpec,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/spec-feature " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/spec.md"
+		},
+	}
+}
+
+func specNeedsApprovalRule() Rule {
+	return Rule{
+		ID: "spec-needs-approval",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseDraft {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactSpec)
+			return art != nil && art.Status == StatusDraft
+		},
+		Action: ActionAwaitApproval,
+		Message: func(_ *EvalContext) string {
+			return "Specification requires user approval"
+		},
+	}
+}
+
+func specApprovedRule() Rule {
+	return Rule{
+		ID: "spec-approved",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseDraft {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactSpec)
+			return art != nil && art.Status == StatusApproved
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhaseSpecified,
+	}
+}
+
+func needsDesignRule() Rule {
+	return Rule{
+		ID: "needs-design",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactDesign)
+			return art == nil || art.Status == StatusPending
+		},
+		Action: ActionCreateDesign,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/design-feature " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/design.md"
+		},
+	}
+}
+
+func designNeedsApprovalRule() Rule {
+	return Rule{
+		ID: "design-needs-approval",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactDesign)
+			return art != nil && (art.Status == StatusDraft || art.Status == StatusRejected)
+		},
+		Action: ActionAwaitApproval,
+		Message: func(_ *EvalContext) string {
+			return "Design document requires user approval"
+		},
+	}
+}
+
+func needsTasksRule() Rule {
+	return Rule{
+		ID: "needs-tasks",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			design := ctx.Feature.GetArtifact(ArtifactDesign)
+			if design == nil || design.Status != StatusApproved {
+				return false
+			}
+			tasks := ctx.Feature.GetArtifact(ArtifactTasks)
+			return tasks == nil || tasks.Status == StatusPending
+		},
+		Action: ActionCreateTasks,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/breakdown-feature " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/tasks.md"
+		},
+	}
+}
+
+func tasksNeedApprovalRule() Rule {
+	return Rule{
+		ID: "tasks-need-approval",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			tasks := ctx.Feature.GetArtifact(ArtifactTasks)
+			return tasks != nil && (tasks.Status == StatusDraft || tasks.Status == StatusRejected)
+		},
+		Action: ActionAwaitApproval,
+		Message: func(_ *EvalContext) string {
+			return "Task breakdown requires user approval"
+		},
+	}
+}
+
+func needsQAPlanRule() Rule {
+	return Rule{
+		ID: "needs-qa-plan",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			tasks := ctx.Feature.GetArtifact(ArtifactTasks)
+			if tasks == nil || tasks.Status != StatusApproved {
+				return false
+			}
+			qa := ctx.Feature.GetArtifact(ArtifactQAPlan)
+			return qa == nil || qa.Status == StatusPending
+		},
+		Action: ActionCreateQAPlan,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/create-qa-plan " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/qa-plan.md"
+		},
+	}
+}
+
+func qaPlanNeedsApprovalRule() Rule {
+	return Rule{
+		ID: "qa-plan-needs-approval",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			qa := ctx.Feature.GetArtifact(ArtifactQAPlan)
+			return qa != nil && (qa.Status == StatusDraft || qa.Status == StatusRejected)
+		},
+		Action: ActionAwaitApproval,
+		Message: func(_ *EvalContext) string {
+			return "QA plan requires user approval"
+		},
+	}
+}
+
+func planningCompleteRule() Rule {
+	return Rule{
+		ID: "planning-complete",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseSpecified {
+				return false
+			}
+			qa := ctx.Feature.GetArtifact(ArtifactQAPlan)
+			return qa != nil && qa.Status == StatusApproved
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhasePlanned,
+	}
+}
+
+func readyToImplementRule() Rule {
+	return Rule{
+		ID: "ready-to-implement",
+		Condition: func(ctx *EvalContext) bool {
+			return ctx.Feature.Phase == PhasePlanned || ctx.Feature.Phase == PhaseReady
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhaseReady,
+		Message: func(ctx *EvalContext) string {
+			if ctx.Feature.Phase == PhasePlanned {
+				return "Ready for implementation: transition to ready, then implementation"
+			}
+			return "Ready for implementation"
+		},
+	}
+}
+
+func implementNextTaskRule() Rule {
+	return Rule{
+		ID: "implement-next-task",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseImplementation {
+				return false
+			}
+			next := NextTask(ctx.Feature.Tasks)
+			return next != nil
+		},
+		Action: ActionImplementTask,
+		NextCommand: func(ctx *EvalContext) string {
+			next := NextTask(ctx.Feature.Tasks)
+			if next == nil {
+				return ""
+			}
+			return fmt.Sprintf("/implement-task %s %s", ctx.Feature.Slug, next.ID)
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/tasks.md"
+		},
+		TaskID: func(ctx *EvalContext) string {
+			next := NextTask(ctx.Feature.Tasks)
+			if next == nil {
+				return ""
+			}
+			return next.ID
+		},
+	}
+}
+
+func implementationCompleteRule() Rule {
+	return Rule{
+		ID: "implementation-complete",
+		Condition: func(ctx *EvalContext) bool {
+			return ctx.Feature.Phase == PhaseImplementation && AllTasksComplete(ctx.Feature.Tasks)
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhaseReview,
+	}
+}
+
+func needsReviewRule() Rule {
+	return Rule{
+		ID: "needs-review",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseReview {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactReview)
+			return art == nil || art.Status == StatusPending
+		},
+		Action: ActionReviewCode,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/review-feature " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/review.md"
+		},
+	}
+}
+
+func reviewHasIssuesRule() Rule {
+	return Rule{
+		ID: "review-has-issues",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseReview {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactReview)
+			return art != nil && art.Status == StatusNeedsFix
+		},
+		Action: ActionFixReviewIssues,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/fix-review-issues " + ctx.Feature.Slug
+		},
+	}
+}
+
+func reviewPassedRule() Rule {
+	return Rule{
+		ID: "review-passed",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseReview {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactReview)
+			return art != nil && art.Status == StatusPassed
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhaseAudit,
+	}
+}
+
+func needsAuditRule() Rule {
+	return Rule{
+		ID: "needs-audit",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseAudit {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactAudit)
+			return art == nil || art.Status == StatusPending
+		},
+		Action: ActionAuditCode,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/audit-feature " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/audit.md"
+		},
+	}
+}
+
+func auditHasIssuesRule() Rule {
+	return Rule{
+		ID: "audit-has-issues",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseAudit {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactAudit)
+			return art != nil && art.Status == StatusNeedsFix
+		},
+		Action: ActionRemediateAudit,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/remediate-audit " + ctx.Feature.Slug
+		},
+	}
+}
+
+func auditPassedRule() Rule {
+	return Rule{
+		ID: "audit-passed",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseAudit {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactAudit)
+			return art != nil && art.Status == StatusPassed
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhaseQA,
+	}
+}
+
+func needsQARule() Rule {
+	return Rule{
+		ID: "needs-qa",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseQA {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactQAResults)
+			return art == nil || art.Status == StatusPending
+		},
+		Action: ActionRunQA,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/run-qa " + ctx.Feature.Slug
+		},
+		OutputPath: func(ctx *EvalContext) string {
+			return ".sdlc/features/" + ctx.Feature.Slug + "/qa-results.md"
+		},
+	}
+}
+
+func qaHasFailuresRule() Rule {
+	return Rule{
+		ID: "qa-has-failures",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseQA {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactQAResults)
+			return art != nil && art.Status == StatusFailed
+		},
+		Action: ActionFixQAFailures,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/fix-qa-failures " + ctx.Feature.Slug
+		},
+	}
+}
+
+func qaPassedRule() Rule {
+	return Rule{
+		ID: "qa-passed",
+		Condition: func(ctx *EvalContext) bool {
+			if ctx.Feature.Phase != PhaseQA {
+				return false
+			}
+			art := ctx.Feature.GetArtifact(ArtifactQAResults)
+			return art != nil && art.Status == StatusPassed
+		},
+		Action:       ActionTransition,
+		TransitionTo: PhaseMerge,
+	}
+}
+
+func needsMergeRule() Rule {
+	return Rule{
+		ID: "needs-merge",
+		Condition: func(ctx *EvalContext) bool {
+			return ctx.Feature.Phase == PhaseMerge
+		},
+		Action: ActionMergeFeature,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/merge-feature " + ctx.Feature.Slug
+		},
+	}
+}
+
+func archiveFeatureRule() Rule {
+	return Rule{
+		ID: "archive-feature",
+		Condition: func(ctx *EvalContext) bool {
+			return ctx.Feature.Phase == PhaseReleased
+		},
+		Action: ActionArchive,
+		NextCommand: func(ctx *EvalContext) string {
+			return "/archive-feature " + ctx.Feature.Slug
+		},
+	}
+}
diff --git a/internal/sdlc/state.go b/internal/sdlc/state.go
new file mode 100644
index 0000000..dceaa50
--- /dev/null
+++ b/internal/sdlc/state.go
@@ -0,0 +1,121 @@
+package sdlc
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+// State represents the global SDLC state stored in .sdlc/state.yaml.
+type State struct {
+	Version     int            `yaml:"version" json:"version"`
+	Project     ProjectState   `yaml:"project" json:"project"`
+	ActiveWork  ActiveWork     `yaml:"active_work" json:"active_work"`
+	Blocked     []BlockedItem  `yaml:"blocked" json:"blocked"`
+	LastUpdated *time.Time     `yaml:"last_updated,omitempty" json:"last_updated,omitempty"`
+	LastAction  string         `yaml:"last_action,omitempty" json:"last_action,omitempty"`
+	LastActor   string         `yaml:"last_actor,omitempty" json:"last_actor,omitempty"`
+	History     []HistoryEntry `yaml:"history,omitempty" json:"history,omitempty"`
+}
+
+// LoadState reads and parses .sdlc/state.yaml from the given project root.
+func LoadState(root string) (*State, error) {
+	path := StatePath(root)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrNotInitialized
+		}
+		return nil, fmt.Errorf("read state file: %w", err)
+	}
+
+	var s State
+	if err := yaml.Unmarshal(data, &s); err != nil {
+		return nil, fmt.Errorf("parse state file: %w", err)
+	}
+	return &s, nil
+}
+
+// Save writes the state to .sdlc/state.yaml.
+func (s *State) Save(root string) error {
+	now := time.Now().UTC()
+	s.LastUpdated = &now
+
+	data, err := yaml.Marshal(s)
+	if err != nil {
+		return fmt.Errorf("marshal state: %w", err)
+	}
+
+	path := StatePath(root)
+	if err := os.WriteFile(path, data, 0o644); err != nil {
+		return fmt.Errorf("write state file: %w", err)
+	}
+	return nil
+}
+
+// RecordAction appends a history entry and updates the last-action fields.
+func (s *State) RecordAction(action, feature, actor string) {
+	entry := HistoryEntry{
+		Timestamp: time.Now().UTC(),
+		Action:    action,
+		Feature:   feature,
+		Actor:     actor,
+		Result:    "success",
+	}
+	s.History = append(s.History, entry)
+	s.LastAction = action
+	s.LastActor = actor
+}
+
+// AddActiveFeature adds a feature to active work if not already present.
+func (s *State) AddActiveFeature(slug string, phase FeaturePhase) {
+	for _, f := range s.ActiveWork.Features {
+		if f.Slug == slug {
+			return
+		}
+	}
+	s.ActiveWork.Features = append(s.ActiveWork.Features, ActiveFeature{
+		Slug:  slug,
+		Phase: phase,
+	})
+}
+
+// UpdateActiveFeature updates the phase of an active feature.
+func (s *State) UpdateActiveFeature(slug string, phase FeaturePhase, branch string) {
+	for i, f := range s.ActiveWork.Features {
+		if f.Slug == slug {
+			s.ActiveWork.Features[i].Phase = phase
+			if branch != "" {
+				s.ActiveWork.Features[i].Branch = branch
+			}
+			return
+		}
+	}
+}
+
+// RemoveActiveFeature removes a feature from active work.
+func (s *State) RemoveActiveFeature(slug string) {
+	for i, f := range s.ActiveWork.Features {
+		if f.Slug == slug {
+			s.ActiveWork.Features = append(s.ActiveWork.Features[:i], s.ActiveWork.Features[i+1:]...)
+			return
+		}
+	}
+}
+
+// DefaultState returns a new State with version 1 and empty fields.
+func DefaultState(projectName string) *State {
+	return &State{
+		Version: 1,
+		Project: ProjectState{
+			Name: projectName,
+		},
+		ActiveWork: ActiveWork{
+			Features: []ActiveFeature{},
+		},
+		Blocked: []BlockedItem{},
+		History: []HistoryEntry{},
+	}
+}
diff --git a/internal/sdlc/state_test.go b/internal/sdlc/state_test.go
new file mode 100644
index 0000000..fe2f59b
--- /dev/null
+++ b/internal/sdlc/state_test.go
@@ -0,0 +1,111 @@
+package sdlc
+
+import (
+	"os"
+	"testing"
+)
+
+func TestStateRoundTrip(t *testing.T) {
+	root := t.TempDir()
+
+	// Create .sdlc directory
+	if err := os.MkdirAll(SDLCRoot(root), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	original := DefaultState("test-project")
+	original.RecordAction("test-action", "auth", "tester")
+	original.AddActiveFeature("auth", PhaseDraft)
+
+	if err := original.Save(root); err != nil {
+		t.Fatalf("Save: %v", err)
+	}
+
+	loaded, err := LoadState(root)
+	if err != nil {
+		t.Fatalf("LoadState: %v", err)
+	}
+
+	if loaded.Version != 1 {
+		t.Errorf("Version = %d, want 1", loaded.Version)
+	}
+	if loaded.Project.Name != "test-project" {
+		t.Errorf("Project.Name = %q, want %q", loaded.Project.Name, "test-project")
+	}
+	if len(loaded.History) != 1 {
+		t.Fatalf("History len = %d, want 1", len(loaded.History))
+	}
+	if loaded.History[0].Action != "test-action" {
+		t.Errorf("History[0].Action = %q, want %q", loaded.History[0].Action, "test-action")
+	}
+	if loaded.LastAction != "test-action" {
+		t.Errorf("LastAction = %q, want %q", loaded.LastAction, "test-action")
+	}
+	if loaded.LastActor != "tester" {
+		t.Errorf("LastActor = %q, want %q", loaded.LastActor, "tester")
+	}
+	if len(loaded.ActiveWork.Features) != 1 {
+		t.Fatalf("ActiveWork.Features len = %d, want 1", len(loaded.ActiveWork.Features))
+	}
+	if loaded.ActiveWork.Features[0].Slug != "auth" {
+		t.Errorf("ActiveWork.Features[0].Slug = %q, want %q", loaded.ActiveWork.Features[0].Slug, "auth")
+	}
+}
+
+func TestLoadStateNotInitialized(t *testing.T) {
+	root := t.TempDir()
+	_, err := LoadState(root)
+	if err != ErrNotInitialized {
+		t.Errorf("LoadState = %v, want ErrNotInitialized", err)
+	}
+}
+
+func TestRecordAction(t *testing.T) {
+	s := DefaultState("test")
+	s.RecordAction("CREATE_SPEC", "auth", "claude")
+	s.RecordAction("TRANSITION", "auth", "classifier")
+
+	if len(s.History) != 2 {
+		t.Fatalf("History len = %d, want 2", len(s.History))
+	}
+	if s.LastAction != "TRANSITION" {
+		t.Errorf("LastAction = %q, want TRANSITION", s.LastAction)
+	}
+}
+
+func TestAddActiveFeatureDeduplicate(t *testing.T) {
+	s := DefaultState("test")
+	s.AddActiveFeature("auth", PhaseDraft)
+	s.AddActiveFeature("auth", PhaseDraft) // duplicate
+
+	if len(s.ActiveWork.Features) != 1 {
+		t.Errorf("Features len = %d, want 1", len(s.ActiveWork.Features))
+	}
+}
+
+func TestUpdateActiveFeature(t *testing.T) {
+	s := DefaultState("test")
+	s.AddActiveFeature("auth", PhaseDraft)
+	s.UpdateActiveFeature("auth", PhaseSpecified, "feature/auth")
+
+	if s.ActiveWork.Features[0].Phase != PhaseSpecified {
+		t.Errorf("Phase = %q, want specified", s.ActiveWork.Features[0].Phase)
+	}
+	if s.ActiveWork.Features[0].Branch != "feature/auth" {
+		t.Errorf("Branch = %q, want feature/auth", s.ActiveWork.Features[0].Branch)
+	}
+}
+
+func TestRemoveActiveFeature(t *testing.T) {
+	s := DefaultState("test")
+	s.AddActiveFeature("auth", PhaseDraft)
+	s.AddActiveFeature("payments", PhaseDraft)
+	s.RemoveActiveFeature("auth")
+
+	if len(s.ActiveWork.Features) != 1 {
+		t.Fatalf("Features len = %d, want 1", len(s.ActiveWork.Features))
+	}
+	if s.ActiveWork.Features[0].Slug != "payments" {
+		t.Errorf("Features[0].Slug = %q, want payments", s.ActiveWork.Features[0].Slug)
+	}
+}
diff --git a/internal/sdlc/task.go b/internal/sdlc/task.go
new file mode 100644
index 0000000..242913d
--- /dev/null
+++ b/internal/sdlc/task.go
@@ -0,0 +1,134 @@
+package sdlc
+
+import (
+	"fmt"
+	"time"
+)
+
+// Task represents an implementation task within a feature.
+type Task struct {
+	ID        string     `yaml:"id" json:"id"`
+	Title     string     `yaml:"title" json:"title"`
+	Status    TaskStatus `yaml:"status" json:"status"`
+	Spec      string     `yaml:"spec,omitempty" json:"spec,omitempty"`
+	Files     []string   `yaml:"files,omitempty" json:"files,omitempty"`
+	Patterns  []string   `yaml:"patterns,omitempty" json:"patterns,omitempty"`
+	DependsOn []string   `yaml:"depends_on,omitempty" json:"depends_on,omitempty"`
+	StartedAt *time.Time `yaml:"started_at,omitempty" json:"started_at,omitempty"`
+	DoneAt    *time.Time `yaml:"done_at,omitempty" json:"done_at,omitempty"`
+	Notes     string     `yaml:"notes,omitempty" json:"notes,omitempty"`
+}
+
+// StartTask marks a task as in-progress.
+func StartTask(tasks []Task, taskID string) ([]Task, error) {
+	for i, t := range tasks {
+		if t.ID == taskID {
+			if t.Status != TaskPending && t.Status != TaskBlocked {
+				return tasks, fmt.Errorf("task %s is %s, not startable", taskID, t.Status)
+			}
+			now := time.Now().UTC()
+			tasks[i].Status = TaskInProgress
+			tasks[i].StartedAt = &now
+			return tasks, nil
+		}
+	}
+	return tasks, ErrTaskNotFound
+}
+
+// CompleteTask marks a task as complete.
+func CompleteTask(tasks []Task, taskID string) ([]Task, error) {
+	for i, t := range tasks {
+		if t.ID == taskID {
+			if t.Status != TaskInProgress {
+				return tasks, fmt.Errorf("task %s is %s, not completable", taskID, t.Status)
+			}
+			now := time.Now().UTC()
+			tasks[i].Status = TaskComplete
+			tasks[i].DoneAt = &now
+			return tasks, nil
+		}
+	}
+	return tasks, ErrTaskNotFound
+}
+
+// BlockTask marks a task as blocked.
+func BlockTask(tasks []Task, taskID string) ([]Task, error) {
+	for i, t := range tasks {
+		if t.ID == taskID {
+			tasks[i].Status = TaskBlocked
+			return tasks, nil
+		}
+	}
+	return tasks, ErrTaskNotFound
+}
+
+// AddTask appends a new task with an auto-generated ID.
+func AddTask(tasks []Task, title string) []Task {
+	id := fmt.Sprintf("task-%03d", len(tasks)+1)
+	return append(tasks, Task{
+		ID:     id,
+		Title:  title,
+		Status: TaskPending,
+	})
+}
+
+// PendingTasks returns tasks that are pending or blocked.
+func PendingTasks(tasks []Task) []Task {
+	var result []Task
+	for _, t := range tasks {
+		if t.Status == TaskPending {
+			result = append(result, t)
+		}
+	}
+	return result
+}
+
+// NextTask returns the first pending task, or nil if none.
+func NextTask(tasks []Task) *Task {
+	for i, t := range tasks {
+		if t.Status == TaskPending {
+			return &tasks[i]
+		}
+	}
+	return nil
+}
+
+// AllTasksComplete returns true if every task is in the complete state.
+func AllTasksComplete(tasks []Task) bool {
+	if len(tasks) == 0 {
+		return false
+	}
+	for _, t := range tasks {
+		if t.Status != TaskComplete {
+			return false
+		}
+	}
+	return true
+}
+
+// TaskSummary returns counts by status.
+type TaskSummary struct {
+	Total      int `json:"total"`
+	Completed  int `json:"completed"`
+	InProgress int `json:"in_progress"`
+	Pending    int `json:"pending"`
+	Blocked    int `json:"blocked"`
+}
+
+// SummarizeTasks computes a TaskSummary from a task list.
+func SummarizeTasks(tasks []Task) TaskSummary {
+	s := TaskSummary{Total: len(tasks)}
+	for _, t := range tasks {
+		switch t.Status {
+		case TaskComplete:
+			s.Completed++
+		case TaskInProgress:
+			s.InProgress++
+		case TaskPending:
+			s.Pending++
+		case TaskBlocked:
+			s.Blocked++
+		}
+	}
+	return s
+}
diff --git a/internal/sdlc/task_test.go b/internal/sdlc/task_test.go
new file mode 100644
index 0000000..70fc8ff
--- /dev/null
+++ b/internal/sdlc/task_test.go
@@ -0,0 +1,163 @@
+package sdlc
+
+import "testing"
+
+func TestAddTask(t *testing.T) {
+	tasks := AddTask(nil, "Create user model")
+	tasks = AddTask(tasks, "Add validation")
+
+	if len(tasks) != 2 {
+		t.Fatalf("len = %d, want 2", len(tasks))
+	}
+	if tasks[0].ID != "task-001" {
+		t.Errorf("tasks[0].ID = %q, want task-001", tasks[0].ID)
+	}
+	if tasks[1].ID != "task-002" {
+		t.Errorf("tasks[1].ID = %q, want task-002", tasks[1].ID)
+	}
+	if tasks[0].Status != TaskPending {
+		t.Errorf("tasks[0].Status = %q, want pending", tasks[0].Status)
+	}
+}
+
+func TestStartTask(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+
+	tasks, err := StartTask(tasks, "task-001")
+	if err != nil {
+		t.Fatalf("StartTask: %v", err)
+	}
+	if tasks[0].Status != TaskInProgress {
+		t.Errorf("Status = %q, want in_progress", tasks[0].Status)
+	}
+	if tasks[0].StartedAt == nil {
+		t.Error("StartedAt is nil")
+	}
+}
+
+func TestStartTaskNotFound(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	_, err := StartTask(tasks, "task-999")
+	if err != ErrTaskNotFound {
+		t.Errorf("err = %v, want ErrTaskNotFound", err)
+	}
+}
+
+func TestStartTaskWrongStatus(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	tasks, _ = StartTask(tasks, "task-001")
+	tasks, _ = CompleteTask(tasks, "task-001")
+
+	_, err := StartTask(tasks, "task-001")
+	if err == nil {
+		t.Error("StartTask on complete task should fail")
+	}
+}
+
+func TestCompleteTask(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	tasks, _ = StartTask(tasks, "task-001")
+
+	tasks, err := CompleteTask(tasks, "task-001")
+	if err != nil {
+		t.Fatalf("CompleteTask: %v", err)
+	}
+	if tasks[0].Status != TaskComplete {
+		t.Errorf("Status = %q, want complete", tasks[0].Status)
+	}
+	if tasks[0].DoneAt == nil {
+		t.Error("DoneAt is nil")
+	}
+}
+
+func TestCompleteTaskWrongStatus(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	_, err := CompleteTask(tasks, "task-001")
+	if err == nil {
+		t.Error("CompleteTask on pending task should fail")
+	}
+}
+
+func TestBlockTask(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	tasks, err := BlockTask(tasks, "task-001")
+	if err != nil {
+		t.Fatalf("BlockTask: %v", err)
+	}
+	if tasks[0].Status != TaskBlocked {
+		t.Errorf("Status = %q, want blocked", tasks[0].Status)
+	}
+}
+
+func TestPendingTasks(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	tasks = AddTask(tasks, "Task 2")
+	tasks = AddTask(tasks, "Task 3")
+	tasks, _ = StartTask(tasks, "task-001")
+	tasks, _ = CompleteTask(tasks, "task-001")
+
+	pending := PendingTasks(tasks)
+	if len(pending) != 2 {
+		t.Errorf("PendingTasks len = %d, want 2", len(pending))
+	}
+}
+
+func TestNextTask(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	tasks = AddTask(tasks, "Task 2")
+	tasks, _ = StartTask(tasks, "task-001")
+	tasks, _ = CompleteTask(tasks, "task-001")
+
+	next := NextTask(tasks)
+	if next == nil {
+		t.Fatal("NextTask = nil, want task-002")
+	}
+	if next.ID != "task-002" {
+		t.Errorf("NextTask.ID = %q, want task-002", next.ID)
+	}
+}
+
+func TestAllTasksComplete(t *testing.T) {
+	if AllTasksComplete(nil) {
+		t.Error("AllTasksComplete(nil) = true, want false")
+	}
+
+	tasks := AddTask(nil, "Task 1")
+	tasks = AddTask(tasks, "Task 2")
+
+	if AllTasksComplete(tasks) {
+		t.Error("AllTasksComplete = true with pending tasks")
+	}
+
+	tasks, _ = StartTask(tasks, "task-001")
+	tasks, _ = CompleteTask(tasks, "task-001")
+	tasks, _ = StartTask(tasks, "task-002")
+	tasks, _ = CompleteTask(tasks, "task-002")
+
+	if !AllTasksComplete(tasks) {
+		t.Error("AllTasksComplete = false with all complete")
+	}
+}
+
+func TestSummarizeTasks(t *testing.T) {
+	tasks := AddTask(nil, "Task 1")
+	tasks = AddTask(tasks, "Task 2")
+	tasks = AddTask(tasks, "Task 3")
+	tasks, _ = StartTask(tasks, "task-001")
+	tasks, _ = CompleteTask(tasks, "task-001")
+	tasks, _ = StartTask(tasks, "task-002")
+
+	s := SummarizeTasks(tasks)
+	if s.Total != 3 {
+		t.Errorf("Total = %d, want 3", s.Total)
+	}
+	if s.Completed != 1 {
+		t.Errorf("Completed = %d, want 1", s.Completed)
+	}
+	if s.InProgress != 1 {
+		t.Errorf("InProgress = %d, want 1", s.InProgress)
+	}
+	if s.Pending != 1 {
+		t.Errorf("Pending = %d, want 1", s.Pending)
+	}
+}
diff --git a/internal/sdlc/types.go b/internal/sdlc/types.go
new file mode 100644
index 0000000..865f4f7
--- /dev/null
+++ b/internal/sdlc/types.go
@@ -0,0 +1,162 @@
+package sdlc
+
+import (
+	"slices"
+	"time"
+)
+
+// FeaturePhase represents a stage in the feature lifecycle.
+type FeaturePhase string
+
+const (
+	PhaseDraft          FeaturePhase = "draft"
+	PhaseSpecified      FeaturePhase = "specified"
+	PhasePlanned        FeaturePhase = "planned"
+	PhaseReady          FeaturePhase = "ready"
+	PhaseImplementation FeaturePhase = "implementation"
+	PhaseReview         FeaturePhase = "review"
+	PhaseAudit          FeaturePhase = "audit"
+	PhaseQA             FeaturePhase = "qa"
+	PhaseMerge          FeaturePhase = "merge"
+	PhaseReleased       FeaturePhase = "released"
+)
+
+// ValidPhases is the ordered list of all feature phases.
+var ValidPhases = []FeaturePhase{
+	PhaseDraft,
+	PhaseSpecified,
+	PhasePlanned,
+	PhaseReady,
+	PhaseImplementation,
+	PhaseReview,
+	PhaseAudit,
+	PhaseQA,
+	PhaseMerge,
+	PhaseReleased,
+}
+
+// PhaseIndex returns the ordinal position of a phase, or -1 if invalid.
+func PhaseIndex(p FeaturePhase) int {
+	for i, v := range ValidPhases {
+		if v == p {
+			return i
+		}
+	}
+	return -1
+}
+
+// IsValidPhase returns true if the phase is recognized.
+func IsValidPhase(p FeaturePhase) bool {
+	return PhaseIndex(p) >= 0
+}
+
+// ArtifactType identifies the kind of artifact produced during a phase.
+type ArtifactType string
+
+const (
+	ArtifactSpec      ArtifactType = "spec"
+	ArtifactDesign    ArtifactType = "design"
+	ArtifactTasks     ArtifactType = "tasks"
+	ArtifactQAPlan    ArtifactType = "qa_plan"
+	ArtifactReview    ArtifactType = "review"
+	ArtifactAudit     ArtifactType = "audit"
+	ArtifactQAResults ArtifactType = "qa_results"
+)
+
+// ValidArtifactTypes lists all recognized artifact types.
+var ValidArtifactTypes = []ArtifactType{
+	ArtifactSpec,
+	ArtifactDesign,
+	ArtifactTasks,
+	ArtifactQAPlan,
+	ArtifactReview,
+	ArtifactAudit,
+	ArtifactQAResults,
+}
+
+// IsValidArtifactType returns true if the artifact type is recognized.
+func IsValidArtifactType(t ArtifactType) bool {
+	return slices.Contains(ValidArtifactTypes, t)
+}
+
+// ArtifactFilename returns the file name for an artifact type.
+func ArtifactFilename(t ArtifactType) string {
+	switch t {
+	case ArtifactSpec:
+		return "spec.md"
+	case ArtifactDesign:
+		return "design.md"
+	case ArtifactTasks:
+		return "tasks.md"
+	case ArtifactQAPlan:
+		return "qa-plan.md"
+	case ArtifactReview:
+		return "review.md"
+	case ArtifactAudit:
+		return "audit.md"
+	case ArtifactQAResults:
+		return "qa-results.md"
+	default:
+		return ""
+	}
+}
+
+// ArtifactStatus tracks the approval state of an artifact.
+type ArtifactStatus string
+
+const (
+	StatusPending  ArtifactStatus = "pending"
+	StatusDraft    ArtifactStatus = "draft"
+	StatusApproved ArtifactStatus = "approved"
+	StatusRejected ArtifactStatus = "rejected"
+	StatusNeedsFix ArtifactStatus = "needs_fix"
+	StatusPassed   ArtifactStatus = "passed"
+	StatusFailed   ArtifactStatus = "failed"
+)
+
+// ActionType identifies what the classifier recommends.
+type ActionType string
+
+const (
+	ActionBlocked         ActionType = "BLOCKED"
+	ActionAwaitApproval   ActionType = "AWAIT_APPROVAL"
+	ActionTransition      ActionType = "TRANSITION"
+	ActionCreateSpec      ActionType = "CREATE_SPEC"
+	ActionCreateDesign    ActionType = "CREATE_DESIGN"
+	ActionCreateTasks     ActionType = "CREATE_TASKS"
+	ActionCreateQAPlan    ActionType = "CREATE_QA_PLAN"
+	ActionCreateBranch    ActionType = "CREATE_BRANCH"
+	ActionImplementTask   ActionType = "IMPLEMENT_TASK"
+	ActionReviewCode      ActionType = "REVIEW_CODE"
+	ActionFixReviewIssues ActionType = "FIX_REVIEW_ISSUES"
+	ActionAuditCode       ActionType = "AUDIT_CODE"
+	ActionRemediateAudit  ActionType = "REMEDIATE_AUDIT"
+	ActionRunQA           ActionType = "RUN_QA"
+	ActionFixQAFailures   ActionType = "FIX_QA_FAILURES"
+	ActionMergeFeature    ActionType = "MERGE_FEATURE"
+	ActionArchive         ActionType = "ARCHIVE"
+	ActionIdle            ActionType = "IDLE"
+)
+
+// TaskStatus tracks the state of an implementation task.
+type TaskStatus string
+
+const (
+	TaskPending    TaskStatus = "pending"
+	TaskInProgress TaskStatus = "in_progress"
+	TaskComplete   TaskStatus = "complete"
+	TaskBlocked    TaskStatus = "blocked"
+)
+
+// PhaseTransition records when a feature moved between phases.
+type PhaseTransition struct {
+	Phase   FeaturePhase `yaml:"phase" json:"phase"`
+	Entered time.Time    `yaml:"entered" json:"entered"`
+	Exited  *time.Time   `yaml:"exited,omitempty" json:"exited,omitempty"`
+}
+
+// Dependencies tracks what a feature depends on.
+type Dependencies struct {
+	Features []string `yaml:"features,omitempty" json:"features,omitempty"`
+	Patterns []string `yaml:"patterns,omitempty" json:"patterns,omitempty"`
+}
diff --git a/internal/service/sdlc_service.go b/internal/service/sdlc_service.go
new file mode 100644
index 0000000..410adcc
--- /dev/null
+++ b/internal/service/sdlc_service.go
@@ -0,0 +1,259 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+
+	"github.com/orchard9/rdev/internal/domain"
+	"github.com/orchard9/rdev/internal/port"
+	"github.com/orchard9/rdev/internal/sdlc"
+)
+
+// SDLCService provides SDLC operations for projects.
+// It resolves project IDs to pod names and delegates to the SDLCExecutor.
+type SDLCService struct {
+	sdlcExec    port.SDLCExecutor
+	projectRepo port.ProjectRepository
+	logger      *slog.Logger
+}
+
+// SDLCServiceConfig configures the SDLC service.
+type SDLCServiceConfig struct {
+	Logger *slog.Logger
+}
+
+// NewSDLCService creates a new SDLC service.
+func NewSDLCService(sdlcExec port.SDLCExecutor, projectRepo port.ProjectRepository, cfg SDLCServiceConfig) *SDLCService {
+	logger := cfg.Logger
+	if logger == nil {
+		logger = slog.Default()
+	}
+	return &SDLCService{
+		sdlcExec:    sdlcExec,
+		projectRepo: projectRepo,
+		logger:      logger.With("component", "sdlc-service"),
+	}
+}
+
+// resolveProjectPod looks up a project and returns its pod name.
+func (s *SDLCService) resolveProjectPod(ctx context.Context, projectID string) (string, error) {
+	project, err := s.projectRepo.Get(ctx, domain.ProjectID(projectID))
+	if err != nil {
+		return "", domain.ErrProjectNotFound
+	}
+	if project.PodName == "" {
+		return "", fmt.Errorf("project %s has no pod", projectID)
+	}
+	return project.PodName, nil
+}
+
+// GetState returns the global SDLC state for a project.
+func (s *SDLCService) GetState(ctx context.Context, projectID string) (*sdlc.State, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.GetState(ctx, podName)
+}
+
+// GetNext returns the classifier's recommendation for the next action.
+func (s *SDLCService) GetNext(ctx context.Context, projectID, feature string) (*sdlc.Classification, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.GetNext(ctx, podName, feature)
+}
+
+// ListFeatures returns all features in a project.
+func (s *SDLCService) ListFeatures(ctx context.Context, projectID string) ([]*sdlc.Feature, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.ListFeatures(ctx, podName)
+}
+
+// GetFeature returns a single feature by slug.
+func (s *SDLCService) GetFeature(ctx context.Context, projectID, slug string) (*sdlc.Feature, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.GetFeature(ctx, podName, slug)
+}
+
+// CreateFeature creates a new feature.
+func (s *SDLCService) CreateFeature(ctx context.Context, projectID, slug, title string) (*sdlc.Feature, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	f, err := s.sdlcExec.CreateFeature(ctx, podName, slug, title)
+	if err != nil {
+		return nil, err
+	}
+	s.logger.Info("feature created", "project", projectID, "feature", slug)
+	return f, nil
+}
+
+// TransitionFeature moves a feature to the specified phase.
+func (s *SDLCService) TransitionFeature(ctx context.Context, projectID, slug string, phase sdlc.FeaturePhase) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	if err := s.sdlcExec.TransitionFeature(ctx, podName, slug, phase); err != nil {
+		s.logger.Error("transition feature failed", "project", projectID, "feature", slug, "phase", string(phase), "error", err)
+		return err
+	}
+	s.logger.Info("feature transitioned", "project", projectID, "feature", slug, "phase", string(phase))
+	return nil
+}
+
+// BlockFeature adds a blocker reason to a feature.
+func (s *SDLCService) BlockFeature(ctx context.Context, projectID, slug, reason string) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	if err := s.sdlcExec.BlockFeature(ctx, podName, slug, reason); err != nil {
+		return err
+	}
+	s.logger.Info("feature blocked", "project", projectID, "feature", slug, "reason", reason)
+	return nil
+}
+
+// UnblockFeature removes all blockers from a feature.
+func (s *SDLCService) UnblockFeature(ctx context.Context, projectID, slug string) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	if err := s.sdlcExec.UnblockFeature(ctx, podName, slug); err != nil {
+		return err
+	}
+	s.logger.Info("feature unblocked", "project", projectID, "feature", slug)
+	return nil
+}
+
+// DeleteFeature removes a feature entirely.
+func (s *SDLCService) DeleteFeature(ctx context.Context, projectID, slug string) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	if err := s.sdlcExec.DeleteFeature(ctx, podName, slug); err != nil {
+		return err
+	}
+	s.logger.Info("feature deleted", "project", projectID, "feature", slug)
+	return nil
+}
+
+// GetArtifactStatus returns artifact statuses for a feature.
+func (s *SDLCService) GetArtifactStatus(ctx context.Context, projectID, slug string) (map[sdlc.ArtifactType]*sdlc.Artifact, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.GetArtifactStatus(ctx, podName, slug)
+}
+
+// ApproveArtifact approves a feature artifact.
+func (s *SDLCService) ApproveArtifact(ctx context.Context, projectID, slug string, artType sdlc.ArtifactType) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	if err := s.sdlcExec.ApproveArtifact(ctx, podName, slug, artType); err != nil {
+		return err
+	}
+	s.logger.Info("artifact approved", "project", projectID, "feature", slug, "artifact", string(artType))
+	return nil
+}
+
+// RejectArtifact rejects a feature artifact.
+func (s *SDLCService) RejectArtifact(ctx context.Context, projectID, slug string, artType sdlc.ArtifactType) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	if err := s.sdlcExec.RejectArtifact(ctx, podName, slug, artType); err != nil {
+		return err
+	}
+	s.logger.Info("artifact rejected", "project", projectID, "feature", slug, "artifact", string(artType))
+	return nil
+}
+
+// ListTasks returns all tasks for a feature.
+func (s *SDLCService) ListTasks(ctx context.Context, projectID, slug string) ([]sdlc.Task, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.ListTasks(ctx, podName, slug)
+}
+
+// AddTask adds a new task to a feature.
+func (s *SDLCService) AddTask(ctx context.Context, projectID, slug, title string) (*sdlc.Task, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.AddTask(ctx, podName, slug, title)
+}
+
+// StartTask marks a task as in-progress.
+func (s *SDLCService) StartTask(ctx context.Context, projectID, slug, taskID string) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	return s.sdlcExec.StartTask(ctx, podName, slug, taskID)
+}
+
+// CompleteTask marks a task as complete.
+func (s *SDLCService) CompleteTask(ctx context.Context, projectID, slug, taskID string) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	return s.sdlcExec.CompleteTask(ctx, podName, slug, taskID)
+}
+
+// BlockTask marks a task as blocked.
+func (s *SDLCService) BlockTask(ctx context.Context, projectID, slug, taskID string) error {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return err
+	}
+	return s.sdlcExec.BlockTask(ctx, podName, slug, taskID)
+}
+
+// QueryBlocked returns all blocked features in a project.
+func (s *SDLCService) QueryBlocked(ctx context.Context, projectID string) ([]port.BlockedInfo, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.QueryBlocked(ctx, podName)
+}
+
+// QueryReady returns features ready for work in a project.
+func (s *SDLCService) QueryReady(ctx context.Context, projectID string) ([]port.ReadyInfo, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.QueryReady(ctx, podName)
+}
+
+// QueryNeedsApproval returns features awaiting approval in a project.
+func (s *SDLCService) QueryNeedsApproval(ctx context.Context, projectID string) ([]port.ApprovalInfo, error) {
+	podName, err := s.resolveProjectPod(ctx, projectID)
+	if err != nil {
+		return nil, err
+	}
+	return s.sdlcExec.QueryNeedsApproval(ctx, podName)
+}
diff --git a/internal/service/sdlc_service_test.go b/internal/service/sdlc_service_test.go
new file mode 100644
index 0000000..08fdc80
--- /dev/null
+++ b/internal/service/sdlc_service_test.go
@@ -0,0 +1,374 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/orchard9/rdev/internal/domain"
+	"github.com/orchard9/rdev/internal/port"
+	"github.com/orchard9/rdev/internal/sdlc"
+)
+
+// mockSDLCExecutor implements port.SDLCExecutor for testing.
+type mockSDLCExecutor struct {
+	getStateFn          func(ctx context.Context, podName string) (*sdlc.State, error)
+	getNextFn           func(ctx context.Context, podName, feature string) (*sdlc.Classification, error)
+	listFeaturesFn      func(ctx context.Context, podName string) ([]*sdlc.Feature, error)
+	getFeatureFn        func(ctx context.Context, podName, slug string) (*sdlc.Feature, error)
+	createFeatureFn     func(ctx context.Context, podName, slug, title string) (*sdlc.Feature, error)
+	transitionFeatureFn func(ctx context.Context, podName, slug string, phase sdlc.FeaturePhase) error
+	blockFeatureFn      func(ctx context.Context, podName, slug, reason string) error
+	unblockFeatureFn    func(ctx context.Context, podName, slug string) error
+	deleteFeatureFn     func(ctx context.Context, podName, slug string) error
+	getArtifactStatusFn func(ctx context.Context, podName, slug string) (map[sdlc.ArtifactType]*sdlc.Artifact, error)
+	approveArtifactFn   func(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error
+	rejectArtifactFn    func(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error
+	listTasksFn         func(ctx context.Context, podName, slug string) ([]sdlc.Task, error)
+	addTaskFn           func(ctx context.Context, podName, slug, title string) (*sdlc.Task, error)
+	startTaskFn         func(ctx context.Context, podName, slug, taskID string) error
+	completeTaskFn      func(ctx context.Context, podName, slug, taskID string) error
+	blockTaskFn         func(ctx context.Context, podName, slug, taskID string) error
+	queryBlockedFn      func(ctx context.Context, podName string) ([]port.BlockedInfo, error)
+	queryReadyFn        func(ctx context.Context, podName string) ([]port.ReadyInfo, error)
+	queryNeedsApprFn    func(ctx context.Context, podName string) ([]port.ApprovalInfo, error)
+}
+
+func (m *mockSDLCExecutor) GetState(ctx context.Context, podName string) (*sdlc.State, error) {
+	if m.getStateFn != nil {
+		return m.getStateFn(ctx, podName)
+	}
+	return &sdlc.State{Version: 1}, nil
+}
+
+func (m *mockSDLCExecutor) GetNext(ctx context.Context, podName, feature string) (*sdlc.Classification, error) {
+	if m.getNextFn != nil {
+		return m.getNextFn(ctx, podName, feature)
+	}
+	return &sdlc.Classification{Action: sdlc.ActionIdle}, nil
+}
+
+func (m *mockSDLCExecutor) ListFeatures(ctx context.Context, podName string) ([]*sdlc.Feature, error) {
+	if m.listFeaturesFn != nil {
+		return m.listFeaturesFn(ctx, podName)
+	}
+	return nil, nil
+}
+
+func (m *mockSDLCExecutor) GetFeature(ctx context.Context, podName, slug string) (*sdlc.Feature, error) {
+	if m.getFeatureFn != nil {
+		return m.getFeatureFn(ctx, podName, slug)
+	}
+	return &sdlc.Feature{Slug: slug}, nil
+}
+
+func (m *mockSDLCExecutor) CreateFeature(ctx context.Context, podName, slug, title string) (*sdlc.Feature, error) {
+	if m.createFeatureFn != nil {
+		return m.createFeatureFn(ctx, podName, slug, title)
+	}
+	return &sdlc.Feature{Slug: slug, Title: title}, nil
+}
+
+func (m *mockSDLCExecutor) TransitionFeature(ctx context.Context, podName, slug string, phase sdlc.FeaturePhase) error {
+	if m.transitionFeatureFn != nil {
+		return m.transitionFeatureFn(ctx, podName, slug, phase)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) BlockFeature(ctx context.Context, podName, slug, reason string) error {
+	if m.blockFeatureFn != nil {
+		return m.blockFeatureFn(ctx, podName, slug, reason)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) UnblockFeature(ctx context.Context, podName, slug string) error {
+	if m.unblockFeatureFn != nil {
+		return m.unblockFeatureFn(ctx, podName, slug)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) DeleteFeature(ctx context.Context, podName, slug string) error {
+	if m.deleteFeatureFn != nil {
+		return m.deleteFeatureFn(ctx, podName, slug)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) GetArtifactStatus(ctx context.Context, podName, slug string) (map[sdlc.ArtifactType]*sdlc.Artifact, error) {
+	if m.getArtifactStatusFn != nil {
+		return m.getArtifactStatusFn(ctx, podName, slug)
+	}
+	return nil, nil
+}
+
+func (m *mockSDLCExecutor) ApproveArtifact(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error {
+	if m.approveArtifactFn != nil {
+		return m.approveArtifactFn(ctx, podName, slug, artType)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) RejectArtifact(ctx context.Context, podName, slug string, artType sdlc.ArtifactType) error {
+	if m.rejectArtifactFn != nil {
+		return m.rejectArtifactFn(ctx, podName, slug, artType)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) ListTasks(ctx context.Context, podName, slug string) ([]sdlc.Task, error) {
+	if m.listTasksFn != nil {
+		return m.listTasksFn(ctx, podName, slug)
+	}
+	return nil, nil
+}
+
+func (m *mockSDLCExecutor) AddTask(ctx context.Context, podName, slug, title string) (*sdlc.Task, error) {
+	if m.addTaskFn != nil {
+		return m.addTaskFn(ctx, podName, slug, title)
+	}
+	return &sdlc.Task{ID: "task-001", Title: title}, nil
+}
+
+func (m *mockSDLCExecutor) StartTask(ctx context.Context, podName, slug, taskID string) error {
+	if m.startTaskFn != nil {
+		return m.startTaskFn(ctx, podName, slug, taskID)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) CompleteTask(ctx context.Context, podName, slug, taskID string) error {
+	if m.completeTaskFn != nil {
+		return m.completeTaskFn(ctx, podName, slug, taskID)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) BlockTask(ctx context.Context, podName, slug, taskID string) error {
+	if m.blockTaskFn != nil {
+		return m.blockTaskFn(ctx, podName, slug, taskID)
+	}
+	return nil
+}
+
+func (m *mockSDLCExecutor) QueryBlocked(ctx context.Context, podName string) ([]port.BlockedInfo, error) {
+	if m.queryBlockedFn != nil {
+		return m.queryBlockedFn(ctx, podName)
+	}
+	return nil, nil
+}
+
+func (m *mockSDLCExecutor) QueryReady(ctx context.Context, podName string) ([]port.ReadyInfo, error) {
+	if m.queryReadyFn != nil {
+		return m.queryReadyFn(ctx, podName)
+	}
+	return nil, nil
+}
+
+func (m *mockSDLCExecutor) QueryNeedsApproval(ctx context.Context, podName string) ([]port.ApprovalInfo, error) {
+	if m.queryNeedsApprFn != nil {
+		return m.queryNeedsApprFn(ctx, podName)
+	}
+	return nil, nil
+}
+
+// mockProjectRepo implements port.ProjectRepository for testing.
+type mockProjectRepo struct {
+	projects map[domain.ProjectID]*domain.Project
+}
+
+func newMockProjectRepo(projects ...*domain.Project) *mockProjectRepo {
+	m := &mockProjectRepo{projects: make(map[domain.ProjectID]*domain.Project)}
+	for _, p := range projects {
+		m.projects[p.ID] = p
+	}
+	return m
+}
+
+func (m *mockProjectRepo) Get(_ context.Context, id domain.ProjectID) (*domain.Project, error) {
+	p, ok := m.projects[id]
+	if !ok {
+		return nil, domain.ErrProjectNotFound
+	}
+	return p, nil
+}
+
+func (m *mockProjectRepo) List(_ context.Context) ([]domain.Project, error) { return nil, nil }
+func (m *mockProjectRepo) Exists(_ context.Context, id domain.ProjectID) (bool, error) {
+	_, ok := m.projects[id]
+	return ok, nil
+}
+func (m *mockProjectRepo) Register(_ context.Context, _ *domain.Project) error    { return nil }
+func (m *mockProjectRepo) Unregister(_ context.Context, _ domain.ProjectID) error { return nil }
+func (m *mockProjectRepo) RefreshStatus(_ context.Context) error                  { return nil }
+
+func newTestService(exec port.SDLCExecutor, repo *mockProjectRepo) *SDLCService {
+	return NewSDLCService(exec, repo, SDLCServiceConfig{})
+}
+
+func TestSDLCService_GetState(t *testing.T) {
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{
+		getStateFn: func(_ context.Context, podName string) (*sdlc.State, error) {
+			if podName != "myproj-pod" {
+				t.Errorf("expected podName myproj-pod, got %s", podName)
+			}
+			return &sdlc.State{Version: 1}, nil
+		},
+	}
+	svc := newTestService(exec, repo)
+
+	state, err := svc.GetState(context.Background(), "myproj")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if state.Version != 1 {
+		t.Errorf("expected version 1, got %d", state.Version)
+	}
+}
+
+func TestSDLCService_ProjectNotFound(t *testing.T) {
+	repo := newMockProjectRepo() // empty
+	exec := &mockSDLCExecutor{}
+	svc := newTestService(exec, repo)
+
+	_, err := svc.GetState(context.Background(), "nonexistent")
+	if !errors.Is(err, domain.ErrProjectNotFound) {
+		t.Errorf("expected ErrProjectNotFound, got %v", err)
+	}
+}
+
+func TestSDLCService_TransitionFeature(t *testing.T) {
+	var calledSlug string
+	var calledPhase sdlc.FeaturePhase
+
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{
+		transitionFeatureFn: func(_ context.Context, _ string, slug string, phase sdlc.FeaturePhase) error {
+			calledSlug = slug
+			calledPhase = phase
+			return nil
+		},
+	}
+	svc := newTestService(exec, repo)
+
+	err := svc.TransitionFeature(context.Background(), "myproj", "auth-flow", sdlc.PhaseSpecified)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if calledSlug != "auth-flow" {
+		t.Errorf("expected slug auth-flow, got %s", calledSlug)
+	}
+	if calledPhase != sdlc.PhaseSpecified {
+		t.Errorf("expected phase specified, got %s", calledPhase)
+	}
+}
+
+func TestSDLCService_TransitionFeature_Error(t *testing.T) {
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{
+		transitionFeatureFn: func(_ context.Context, _, _ string, _ sdlc.FeaturePhase) error {
+			return sdlc.ErrInvalidTransition
+		},
+	}
+	svc := newTestService(exec, repo)
+
+	err := svc.TransitionFeature(context.Background(), "myproj", "auth-flow", sdlc.PhaseReview)
+	if !errors.Is(err, sdlc.ErrInvalidTransition) {
+		t.Errorf("expected ErrInvalidTransition, got %v", err)
+	}
+}
+
+func TestSDLCService_CreateFeature(t *testing.T) {
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{}
+	svc := newTestService(exec, repo)
+
+	f, err := svc.CreateFeature(context.Background(), "myproj", "new-feature", "New Feature")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if f.Slug != "new-feature" {
+		t.Errorf("expected slug new-feature, got %s", f.Slug)
+	}
+}
+
+func TestSDLCService_ApproveArtifact(t *testing.T) {
+	var calledArtType sdlc.ArtifactType
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{
+		approveArtifactFn: func(_ context.Context, _, _ string, artType sdlc.ArtifactType) error {
+			calledArtType = artType
+			return nil
+		},
+	}
+	svc := newTestService(exec, repo)
+
+	err := svc.ApproveArtifact(context.Background(), "myproj", "auth-flow", sdlc.ArtifactSpec)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if calledArtType != sdlc.ArtifactSpec {
+		t.Errorf("expected artifact type spec, got %s", calledArtType)
+	}
+}
+
+func TestSDLCService_QueryBlocked(t *testing.T) {
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{
+		queryBlockedFn: func(_ context.Context, _ string) ([]port.BlockedInfo, error) {
+			return []port.BlockedInfo{
+				{Slug: "auth", Phase: "implementation", Blockers: []string{"needs API key"}},
+			}, nil
+		},
+	}
+	svc := newTestService(exec, repo)
+
+	blocked, err := svc.QueryBlocked(context.Background(), "myproj")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(blocked) != 1 {
+		t.Fatalf("expected 1 blocked item, got %d", len(blocked))
+	}
+	if blocked[0].Slug != "auth" {
+		t.Errorf("expected slug auth, got %s", blocked[0].Slug)
+	}
+}
+
+func TestSDLCService_AddTask(t *testing.T) {
+	repo := newMockProjectRepo(&domain.Project{
+		ID:      "myproj",
+		PodName: "myproj-pod",
+	})
+	exec := &mockSDLCExecutor{}
+	svc := newTestService(exec, repo)
+
+	task, err := svc.AddTask(context.Background(), "myproj", "auth-flow", "Add login form")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if task.Title != "Add login form" {
+		t.Errorf("expected title 'Add login form', got %s", task.Title)
+	}
+}