build: /implement-feature user-preferences

.sdlc/features/user-preferences/manifest.yaml

@@ -1,7 +1,7 @@
 slug: user-preferences
 title: User Preferences API
 created: 2026-02-09T03:07:55.541048432Z
-phase: ready
+phase: implementation
 phase_history:
     - phase: draft
       entered: 2026-02-09T03:07:55.541048432Z
@@ -14,6 +14,9 @@ phase_history:
       exited: 2026-02-09T03:20:30.611901038Z
     - phase: ready
       entered: 2026-02-09T03:20:30.611901038Z
+      exited: 2026-02-09T03:22:37.766271477Z
+    - phase: implementation
+      entered: 2026-02-09T03:22:37.766271477Z
 artifacts:
     audit:
         status: pending
@@ -45,25 +48,40 @@ artifacts:
         approved_by: user
         approved_at: 2026-02-09T03:18:20.547304636Z
         total: 7
+        completed: 7
 tasks:
     - id: task-001
       title: Domain layer - UserPreferences model and domain errors
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:22:45.05034374Z
+      done_at: 2026-02-09T03:23:09.596316012Z
     - id: task-002
       title: Port layer - PreferenceRepository interface
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:23:15.366917585Z
+      done_at: 2026-02-09T03:23:28.228255343Z
     - id: task-003
       title: Service layer - PreferenceService with validation logic and tests
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:23:34.579590762Z
+      done_at: 2026-02-09T03:24:56.650842143Z
     - id: task-004
       title: Database migration and PostgreSQL adapter
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:25:05.810659873Z
+      done_at: 2026-02-09T03:25:35.931875082Z
     - id: task-005
       title: HTTP handlers - GET and PUT preference endpoints with tests
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:25:41.767966428Z
+      done_at: 2026-02-09T03:27:06.980076413Z
     - id: task-006
       title: Routes, OpenAPI spec, and main.go wiring
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:27:14.505352647Z
+      done_at: 2026-02-09T03:28:39.057928335Z
     - id: task-007
       title: Cleanup - Remove example scaffolding files
-      status: pending
+      status: complete
+      started_at: 2026-02-09T03:28:46.479063131Z
+      done_at: 2026-02-09T03:29:25.590171477Z

.sdlc/state.yaml

@@ -4,10 +4,10 @@ project:
 active_work:
     features:
         - slug: user-preferences
-          phase: ready
+          phase: implementation
 blocked: []
-last_updated: 2026-02-09T03:20:30.626836394Z
+last_updated: 2026-02-09T03:29:25.591047245Z
-last_action: TRANSITION
+last_action: COMPLETE_TASK
 last_actor: cli
 history:
     - timestamp: 2026-02-09T03:07:55.541429198Z
@@ -50,3 +50,43 @@ history:
       feature: user-preferences
       actor: cli
       result: success
+    - timestamp: 2026-02-09T03:22:37.76692675Z
+      action: TRANSITION
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:23:09.597746864Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:23:28.229040239Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:24:56.651563771Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:25:35.93266556Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:27:06.98073376Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:28:39.058628874Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success
+    - timestamp: 2026-02-09T03:29:25.591045923Z
+      action: COMPLETE_TASK
+      feature: user-preferences
+      actor: cli
+      result: success

go.work

@@ -1,5 +1,9 @@
-go 1.23
+go 1.24.0
+
+toolchain go1.24.13
 
 use ./pkg
+
 use ./services/preferences-api
+
 // Component modules will be added below

services/preferences-api/cmd/server/main.go

@@ -2,17 +2,24 @@
 package main
 
 import (
+	"context"
+	"embed"
 	"flag"
 	"fmt"
 	"os"
 
 	"git.threesix.ai/jordan/slack5-1770606136/pkg/app"
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/config"
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/database"
 	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/adapter/memory"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/adapter/postgres"
 	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/api"
 	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/service"
 )
 
+//go:embed migrations/*.sql
+var migrationsFS embed.FS
+
 func main() {
 	// Parse flags
 	exportOpenAPI := flag.Bool("export-openapi", false, "Export OpenAPI spec to stdout and exit")
@@ -33,17 +40,29 @@ func main() {
 	// Create logger
 	logger := logging.Default()
 
+	// Connect to PostgreSQL
+	dbCfg := config.ReadDatabaseConfig()
+	pool := database.MustConnect(context.Background(), dbCfg.URL, database.Options{
+		MaxOpenConns:    dbCfg.MaxOpenConns,
+		MaxIdleConns:    dbCfg.MaxIdleConns,
+		ConnMaxLifetime: dbCfg.ConnMaxLifetime,
+	})
+	defer pool.Close()
+
+	// Run migrations
+	database.MustRunMigrations(context.Background(), pool, migrationsFS, "migrations")
+
 	// Create adapters (repositories)
-	exampleRepo := memory.NewExampleRepository()
+	prefRepo := postgres.NewPreferenceRepository(pool.DB)
 
 	// Create services (business logic)
-	exampleService := service.NewExampleService(exampleRepo, logger)
+	prefService := service.NewPreferenceService(prefRepo, logger)
 
 	// Create application
 	application := app.New("preferences-api", app.WithDefaultPort(8001))
 
 	// Register routes with dependency injection
-	api.RegisterRoutes(application, exampleService)
+	api.RegisterRoutes(application, prefService)
 
 	// Start server
 	application.Run()

services/preferences-api/cmd/server/migrations/001_create_preferences.sql

@@ -0,0 +1,8 @@
+CREATE TABLE IF NOT EXISTS preferences (
+    user_id     UUID PRIMARY KEY,
+    preferences JSONB NOT NULL DEFAULT '{}',
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_preferences_updated_at ON preferences (updated_at);

services/preferences-api/go.mod

@@ -1,8 +1,12 @@
 module git.threesix.ai/jordan/slack5-1770606136/services/preferences-api
 
-go 1.23
+go 1.24.0
+
+toolchain go1.24.13
 
 require git.threesix.ai/jordan/slack5-1770606136/pkg v0.0.0
 
+require golang.org/x/text v0.33.0 // indirect
+
 // Use local workspace modules (for Docker builds without go.work)
 replace git.threesix.ai/jordan/slack5-1770606136/pkg => ../../pkg

services/preferences-api/go.sum

@@ -0,0 +1,2 @@
+golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
+golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=

services/preferences-api/internal/adapter/memory/example.go

@@ -1,106 +0,0 @@
-// Package memory provides in-memory implementations of repository interfaces.
-// Useful for development, testing, and prototyping.
-package memory
-
-import (
-	"context"
-	"sync"
-
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
-)
-
-// Compile-time verification that ExampleRepository implements port.ExampleRepository.
-var _ port.ExampleRepository = (*ExampleRepository)(nil)
-
-// ExampleRepository is a thread-safe in-memory implementation of port.ExampleRepository.
-type ExampleRepository struct {
-	mu       sync.RWMutex
-	examples map[domain.ExampleID]*domain.Example
-}
-
-// NewExampleRepository creates a new in-memory example repository.
-func NewExampleRepository() *ExampleRepository {
-	return &ExampleRepository{
-		examples: make(map[domain.ExampleID]*domain.Example),
-	}
-}
-
-// List returns all examples.
-func (r *ExampleRepository) List(ctx context.Context) ([]domain.Example, error) {
-	r.mu.RLock()
-	defer r.mu.RUnlock()
-
-	result := make([]domain.Example, 0, len(r.examples))
-	for _, e := range r.examples {
-		result = append(result, *e)
-	}
-	return result, nil
-}
-
-// Get returns an example by ID.
-// Returns domain.ErrExampleNotFound if not found.
-func (r *ExampleRepository) Get(ctx context.Context, id domain.ExampleID) (*domain.Example, error) {
-	r.mu.RLock()
-	defer r.mu.RUnlock()
-
-	e, ok := r.examples[id]
-	if !ok {
-		return nil, domain.ErrExampleNotFound
-	}
-	// Return a copy to prevent external mutation
-	copy := *e
-	return &copy, nil
-}
-
-// Create stores a new example.
-func (r *ExampleRepository) Create(ctx context.Context, example *domain.Example) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	// Store a copy to prevent external mutation
-	copy := *example
-	r.examples[example.ID] = &copy
-	return nil
-}
-
-// Update modifies an existing example.
-// Returns domain.ErrExampleNotFound if not found.
-func (r *ExampleRepository) Update(ctx context.Context, example *domain.Example) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	if _, ok := r.examples[example.ID]; !ok {
-		return domain.ErrExampleNotFound
-	}
-	// Store a copy to prevent external mutation
-	copy := *example
-	r.examples[example.ID] = &copy
-	return nil
-}
-
-// Delete removes an example by ID.
-// Returns domain.ErrExampleNotFound if not found.
-func (r *ExampleRepository) Delete(ctx context.Context, id domain.ExampleID) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	if _, ok := r.examples[id]; !ok {
-		return domain.ErrExampleNotFound
-	}
-	delete(r.examples, id)
-	return nil
-}
-
-// ExistsByName checks if an example with the given name exists.
-func (r *ExampleRepository) ExistsByName(ctx context.Context, name string) (bool, error) {
-	r.mu.RLock()
-	defer r.mu.RUnlock()
-
-	for _, e := range r.examples {
-		if e.Name == name {
-			return true, nil
-		}
-	}
-	return false, nil
-}

services/preferences-api/internal/adapter/postgres/preference.go

@@ -0,0 +1,80 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"time"
+
+	"github.com/jmoiron/sqlx"
+
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
+)
+
+// PreferenceRepository implements port.PreferenceRepository using PostgreSQL.
+type PreferenceRepository struct {
+	db *sqlx.DB
+}
+
+// Compile-time interface verification.
+var _ port.PreferenceRepository = (*PreferenceRepository)(nil)
+
+// NewPreferenceRepository creates a new PostgreSQL preference repository.
+func NewPreferenceRepository(db *sqlx.DB) *PreferenceRepository {
+	return &PreferenceRepository{db: db}
+}
+
+// preferenceRow represents a database row from the preferences table.
+type preferenceRow struct {
+	UserID      string    `db:"user_id"`
+	Preferences []byte    `db:"preferences"`
+	CreatedAt   time.Time `db:"created_at"`
+	UpdatedAt   time.Time `db:"updated_at"`
+}
+
+// Get returns preferences for a user.
+// Returns nil, nil when no row exists.
+func (r *PreferenceRepository) Get(ctx context.Context, userID string) (*domain.UserPreferences, error) {
+	var row preferenceRow
+	err := r.db.GetContext(ctx, &row,
+		`SELECT user_id, preferences, created_at, updated_at FROM preferences WHERE user_id = $1`,
+		userID,
+	)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, nil
+		}
+		return nil, err
+	}
+
+	prefs := make(map[string]any)
+	if err := json.Unmarshal(row.Preferences, &prefs); err != nil {
+		return nil, err
+	}
+
+	return &domain.UserPreferences{
+		UserID:      row.UserID,
+		Preferences: prefs,
+		CreatedAt:   row.CreatedAt,
+		UpdatedAt:   row.UpdatedAt,
+	}, nil
+}
+
+// Upsert creates or updates preferences for a user.
+func (r *PreferenceRepository) Upsert(ctx context.Context, prefs *domain.UserPreferences) error {
+	prefsJSON, err := json.Marshal(prefs.Preferences)
+	if err != nil {
+		return err
+	}
+
+	_, err = r.db.ExecContext(ctx,
+		`INSERT INTO preferences (user_id, preferences, updated_at)
+		VALUES ($1, $2, NOW())
+		ON CONFLICT (user_id) DO UPDATE
+		SET preferences = $2, updated_at = NOW()`,
+		prefs.UserID, prefsJSON,
+	)
+	return err
+}

services/preferences-api/internal/api/handlers/example.go

@@ -1,170 +0,0 @@
-package handlers
-
-import (
-	"errors"
-	"net/http"
-
-	"github.com/go-chi/chi/v5"
-	"github.com/google/uuid"
-
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/app"
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/httperror"
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/httpresponse"
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/service"
-)
-
-// Example handles HTTP requests for example resources.
-type Example struct {
-	svc    *service.ExampleService
-	logger *logging.Logger
-}
-
-// NewExample creates a new Example handler with injected dependencies.
-func NewExample(svc *service.ExampleService, logger *logging.Logger) *Example {
-	return &Example{
-		svc:    svc,
-		logger: logger.WithComponent("ExampleHandler"),
-	}
-}
-
-// CreateRequest is the request body for creating an example.
-type CreateRequest struct {
-	Name        string `json:"name" validate:"required,min=1,max=100"`
-	Description string `json:"description" validate:"max=500"`
-}
-
-// UpdateRequest is the request body for updating an example.
-type UpdateRequest struct {
-	Name        string `json:"name" validate:"required,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"`
-}
-
-// toResponse converts a domain example to an API response.
-func toResponse(e *domain.Example) ExampleResponse {
-	return ExampleResponse{
-		ID:          e.ID.String(),
-		Name:        e.Name,
-		Description: e.Description,
-		CreatedAt:   e.CreatedAt.Format("2006-01-02T15:04:05Z"),
-		UpdatedAt:   e.UpdatedAt.Format("2006-01-02T15:04:05Z"),
-	}
-}
-
-// List returns all examples.
-func (h *Example) List(w http.ResponseWriter, r *http.Request) error {
-	examples, err := h.svc.List(r.Context())
-	if err != nil {
-		return err
-	}
-
-	result := make([]ExampleResponse, len(examples))
-	for i, e := range examples {
-		result[i] = toResponse(&e)
-	}
-
-	httpresponse.OK(w, r, result)
-	return nil
-}
-
-// Get returns an example by ID.
-func (h *Example) Get(w http.ResponseWriter, r *http.Request) error {
-	id := chi.URLParam(r, "id")
-
-	// Validate UUID format
-	if _, err := uuid.Parse(id); err != nil {
-		return httperror.BadRequest("invalid id format")
-	}
-
-	example, err := h.svc.Get(r.Context(), domain.ExampleID(id))
-	if err != nil {
-		return mapDomainError(err)
-	}
-
-	httpresponse.OK(w, r, toResponse(example))
-	return nil
-}
-
-// Create creates a new example.
-func (h *Example) Create(w http.ResponseWriter, r *http.Request) error {
-	var req CreateRequest
-	if err := app.BindAndValidate(r, &req); err != nil {
-		return err
-	}
-
-	example, err := h.svc.Create(r.Context(), service.CreateInput{
-		Name:        req.Name,
-		Description: req.Description,
-	})
-	if err != nil {
-		return mapDomainError(err)
-	}
-
-	httpresponse.Created(w, r, toResponse(example))
-	return nil
-}
-
-// Update updates an existing example.
-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, err := h.svc.Update(r.Context(), domain.ExampleID(id), service.UpdateInput{
-		Name:        req.Name,
-		Description: req.Description,
-	})
-	if err != nil {
-		return mapDomainError(err)
-	}
-
-	httpresponse.OK(w, r, toResponse(example))
-	return nil
-}
-
-// Delete removes an example by ID.
-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")
-	}
-
-	if err := h.svc.Delete(r.Context(), domain.ExampleID(id)); err != nil {
-		return mapDomainError(err)
-	}
-
-	httpresponse.NoContent(w)
-	return nil
-}
-
-// mapDomainError converts domain errors to HTTP errors.
-func mapDomainError(err error) error {
-	switch {
-	case errors.Is(err, domain.ErrExampleNotFound):
-		return httperror.NotFound("example not found")
-	case errors.Is(err, domain.ErrDuplicateExample):
-		return httperror.Conflict("example with this name already exists")
-	case errors.Is(err, domain.ErrInvalidExampleName):
-		return httperror.BadRequest("invalid example name")
-	default:
-		return err
-	}
-}

services/preferences-api/internal/api/handlers/example_test.go

@@ -1,402 +0,0 @@
-package handlers
-
-import (
-	"bytes"
-	"context"
-	"encoding/json"
-	"net/http"
-	"net/http/httptest"
-	"sync"
-	"testing"
-
-	"github.com/go-chi/chi/v5"
-
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/service"
-)
-
-// mockExampleRepository implements port.ExampleRepository for testing.
-type mockExampleRepository struct {
-	mu       sync.RWMutex
-	examples map[domain.ExampleID]*domain.Example
-}
-
-var _ port.ExampleRepository = (*mockExampleRepository)(nil)
-
-func newMockExampleRepository() *mockExampleRepository {
-	return &mockExampleRepository{
-		examples: make(map[domain.ExampleID]*domain.Example),
-	}
-}
-
-func (m *mockExampleRepository) List(ctx context.Context) ([]domain.Example, error) {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-
-	result := make([]domain.Example, 0, len(m.examples))
-	for _, e := range m.examples {
-		result = append(result, *e)
-	}
-	return result, nil
-}
-
-func (m *mockExampleRepository) Get(ctx context.Context, id domain.ExampleID) (*domain.Example, error) {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-
-	e, ok := m.examples[id]
-	if !ok {
-		return nil, domain.ErrExampleNotFound
-	}
-	copy := *e
-	return &copy, nil
-}
-
-func (m *mockExampleRepository) Create(ctx context.Context, example *domain.Example) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	copy := *example
-	m.examples[example.ID] = &copy
-	return nil
-}
-
-func (m *mockExampleRepository) Update(ctx context.Context, example *domain.Example) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if _, ok := m.examples[example.ID]; !ok {
-		return domain.ErrExampleNotFound
-	}
-	copy := *example
-	m.examples[example.ID] = &copy
-	return nil
-}
-
-func (m *mockExampleRepository) Delete(ctx context.Context, id domain.ExampleID) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if _, ok := m.examples[id]; !ok {
-		return domain.ErrExampleNotFound
-	}
-	delete(m.examples, id)
-	return nil
-}
-
-func (m *mockExampleRepository) ExistsByName(ctx context.Context, name string) (bool, error) {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-
-	for _, e := range m.examples {
-		if e.Name == name {
-			return true, nil
-		}
-	}
-	return false, nil
-}
-
-func newTestHandler() (*Example, *mockExampleRepository) {
-	repo := newMockExampleRepository()
-	svc := service.NewExampleService(repo, logging.Nop())
-	handler := NewExample(svc, logging.Nop())
-	return handler, repo
-}
-
-func TestExample_List(t *testing.T) {
-	handler, repo := newTestHandler()
-
-	// Seed data
-	ex, _ := domain.NewExample("test-id-1", "Test Example", "Description")
-	_ = repo.Create(context.Background(), ex)
-
-	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) != 1 {
-		t.Errorf("expected 1 item, got %d", len(items))
-	}
-}
-
-func TestExample_Get(t *testing.T) {
-	handler, repo := newTestHandler()
-
-	// Seed data
-	ex, _ := domain.NewExample("550e8400-e29b-41d4-a716-446655440000", "Test Example", "Description")
-	_ = repo.Create(context.Background(), ex)
-
-	tests := []struct {
-		name       string
-		id         string
-		wantStatus int
-	}{
-		{
-			name:       "valid uuid - found",
-			id:         "550e8400-e29b-41d4-a716-446655440000",
-			wantStatus: http.StatusOK,
-		},
-		{
-			name:       "valid uuid - not found",
-			id:         "550e8400-e29b-41d4-a716-446655440001",
-			wantStatus: http.StatusNotFound,
-		},
-		{
-			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 {
-					// Map error to status for testing
-					switch tt.wantStatus {
-					case http.StatusNotFound:
-						w.WriteHeader(http.StatusNotFound)
-					case http.StatusBadRequest:
-						w.WriteHeader(http.StatusBadRequest)
-					default:
-						w.WriteHeader(http.StatusInternalServerError)
-					}
-					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, repo := newTestHandler()
-
-	// Seed existing data for duplicate test
-	ex, _ := domain.NewExample("existing-id", "Existing Name", "")
-	_ = repo.Create(context.Background(), ex)
-
-	tests := []struct {
-		name       string
-		body       any
-		wantStatus int
-	}{
-		{
-			name: "valid request",
-			body: CreateRequest{
-				Name:        "New Example",
-				Description: "A test description",
-			},
-			wantStatus: http.StatusCreated,
-		},
-		{
-			name:       "empty body",
-			body:       nil,
-			wantStatus: http.StatusBadRequest,
-		},
-		{
-			name: "duplicate name",
-			body: CreateRequest{
-				Name:        "Existing Name",
-				Description: "Conflict",
-			},
-			wantStatus: http.StatusConflict,
-		},
-	}
-
-	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 {
-					switch tt.wantStatus {
-					case http.StatusBadRequest:
-						w.WriteHeader(http.StatusBadRequest)
-					case http.StatusConflict:
-						w.WriteHeader(http.StatusConflict)
-					default:
-						w.WriteHeader(http.StatusInternalServerError)
-					}
-					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)
-
-			if w.Code != tt.wantStatus {
-				t.Errorf("expected status %d, got %d", tt.wantStatus, w.Code)
-			}
-		})
-	}
-}
-
-func TestExample_Delete(t *testing.T) {
-	handler, repo := newTestHandler()
-
-	// Seed data
-	ex, _ := domain.NewExample("550e8400-e29b-41d4-a716-446655440000", "To Delete", "")
-	_ = repo.Create(context.Background(), ex)
-
-	tests := []struct {
-		name       string
-		id         string
-		wantStatus int
-	}{
-		{
-			name:       "existing example",
-			id:         "550e8400-e29b-41d4-a716-446655440000",
-			wantStatus: http.StatusNoContent,
-		},
-		{
-			name:       "non-existent example",
-			id:         "550e8400-e29b-41d4-a716-446655440001",
-			wantStatus: http.StatusNotFound,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := chi.NewRouter()
-			r.Delete("/api/v1/examples/{id}", func(w http.ResponseWriter, r *http.Request) {
-				if err := handler.Delete(w, r); err != nil {
-					if tt.wantStatus == http.StatusNotFound {
-						w.WriteHeader(http.StatusNotFound)
-					} else {
-						w.WriteHeader(http.StatusBadRequest)
-					}
-					return
-				}
-			})
-
-			req := httptest.NewRequest(http.MethodDelete, "/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_Update(t *testing.T) {
-	handler, repo := newTestHandler()
-
-	// Seed data
-	ex1, _ := domain.NewExample("550e8400-e29b-41d4-a716-446655440000", "Example 1", "")
-	_ = repo.Create(context.Background(), ex1)
-	ex2, _ := domain.NewExample("550e8400-e29b-41d4-a716-446655440001", "Example 2", "")
-	_ = repo.Create(context.Background(), ex2)
-
-	tests := []struct {
-		name       string
-		id         string
-		body       UpdateRequest
-		wantStatus int
-	}{
-		{
-			name: "valid update",
-			id:   "550e8400-e29b-41d4-a716-446655440000",
-			body: UpdateRequest{
-				Name:        "Updated Name",
-				Description: "Updated",
-			},
-			wantStatus: http.StatusOK,
-		},
-		{
-			name: "name conflict",
-			id:   "550e8400-e29b-41d4-a716-446655440000",
-			body: UpdateRequest{
-				Name:        "Example 2",
-				Description: "Conflict",
-			},
-			wantStatus: http.StatusConflict,
-		},
-		{
-			name: "not found",
-			id:   "550e8400-e29b-41d4-a716-446655440099",
-			body: UpdateRequest{
-				Name:        "Whatever",
-				Description: "",
-			},
-			wantStatus: http.StatusNotFound,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := chi.NewRouter()
-			r.Put("/api/v1/examples/{id}", func(w http.ResponseWriter, r *http.Request) {
-				if err := handler.Update(w, r); err != nil {
-					switch tt.wantStatus {
-					case http.StatusNotFound:
-						w.WriteHeader(http.StatusNotFound)
-					case http.StatusConflict:
-						w.WriteHeader(http.StatusConflict)
-					default:
-						w.WriteHeader(http.StatusBadRequest)
-					}
-					return
-				}
-			})
-
-			body, _ := json.Marshal(tt.body)
-			req := httptest.NewRequest(http.MethodPut, "/api/v1/examples/"+tt.id, bytes.NewReader(body))
-			req.Header.Set("Content-Type", "application/json")
-			w := httptest.NewRecorder()
-			r.ServeHTTP(w, req)
-
-			if w.Code != tt.wantStatus {
-				t.Errorf("expected status %d, got %d", tt.wantStatus, w.Code)
-			}
-		})
-	}
-}

services/preferences-api/internal/api/handlers/preference.go

@@ -0,0 +1,122 @@
+package handlers
+
+import (
+	"errors"
+	"net/http"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/google/uuid"
+
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/app"
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/httperror"
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/httpresponse"
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/service"
+)
+
+// Preference handles HTTP requests for user preference resources.
+type Preference struct {
+	svc    *service.PreferenceService
+	logger *logging.Logger
+}
+
+// NewPreference creates a new Preference handler with injected dependencies.
+func NewPreference(svc *service.PreferenceService, logger *logging.Logger) *Preference {
+	return &Preference{
+		svc:    svc,
+		logger: logger.WithComponent("PreferenceHandler"),
+	}
+}
+
+// UpdatePreferencesRequest is the request body for updating preferences.
+type UpdatePreferencesRequest struct {
+	Preferences map[string]any `json:"preferences"`
+}
+
+// PreferenceResponse is the response for a preference resource.
+type PreferenceResponse struct {
+	UserID      string         `json:"user_id"`
+	Preferences map[string]any `json:"preferences"`
+	UpdatedAt   string         `json:"updated_at"`
+}
+
+// Get returns preferences for a user.
+func (h *Preference) Get(w http.ResponseWriter, r *http.Request) error {
+	userID := chi.URLParam(r, "user_id")
+
+	if _, err := uuid.Parse(userID); err != nil {
+		return httperror.BadRequest("invalid user_id format")
+	}
+
+	prefs, err := h.svc.Get(r.Context(), userID)
+	if err != nil {
+		return err
+	}
+
+	if prefs == nil {
+		httpresponse.OK(w, r, PreferenceResponse{
+			UserID:      userID,
+			Preferences: map[string]any{},
+			UpdatedAt:   time.Now().UTC().Format(time.RFC3339),
+		})
+		return nil
+	}
+
+	httpresponse.OK(w, r, toPreferenceResponse(prefs))
+	return nil
+}
+
+// Upsert creates or updates preferences for a user.
+func (h *Preference) Upsert(w http.ResponseWriter, r *http.Request) error {
+	userID := chi.URLParam(r, "user_id")
+
+	if _, err := uuid.Parse(userID); err != nil {
+		return httperror.BadRequest("invalid user_id format")
+	}
+
+	var req UpdatePreferencesRequest
+	if err := app.Bind(r, &req); err != nil {
+		return err
+	}
+
+	if req.Preferences == nil {
+		return httperror.BadRequest("preferences field is required")
+	}
+
+	result, err := h.svc.Upsert(r.Context(), service.UpsertInput{
+		UserID:      userID,
+		Preferences: req.Preferences,
+	})
+	if err != nil {
+		return mapPreferenceDomainError(err)
+	}
+
+	httpresponse.OK(w, r, toPreferenceResponse(result))
+	return nil
+}
+
+// toPreferenceResponse converts a domain UserPreferences to an API response.
+func toPreferenceResponse(p *domain.UserPreferences) PreferenceResponse {
+	return PreferenceResponse{
+		UserID:      p.UserID,
+		Preferences: p.Preferences,
+		UpdatedAt:   p.UpdatedAt.Format(time.RFC3339),
+	}
+}
+
+// mapPreferenceDomainError converts domain errors to HTTP errors.
+func mapPreferenceDomainError(err error) error {
+	if errors.Is(err, domain.ErrInvalidPreferenceValue) {
+		var valErr *service.ValidationError
+		if errors.As(err, &valErr) {
+			return httperror.WithDetails(
+				httperror.Validation("Invalid preference values"),
+				valErr.Details,
+			)
+		}
+		return httperror.BadRequest("invalid preference value")
+	}
+	return err
+}

services/preferences-api/internal/api/handlers/preference_test.go

@@ -0,0 +1,272 @@
+package handlers
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/httperror"
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/service"
+)
+
+// mockPreferenceRepository implements port.PreferenceRepository for handler testing.
+type mockPreferenceRepository struct {
+	mu    sync.RWMutex
+	prefs map[string]*domain.UserPreferences
+}
+
+var _ port.PreferenceRepository = (*mockPreferenceRepository)(nil)
+
+func newMockPrefRepository() *mockPreferenceRepository {
+	return &mockPreferenceRepository{
+		prefs: make(map[string]*domain.UserPreferences),
+	}
+}
+
+func (m *mockPreferenceRepository) Get(ctx context.Context, userID string) (*domain.UserPreferences, error) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+
+	p, ok := m.prefs[userID]
+	if !ok {
+		return nil, nil
+	}
+	cp := *p
+	cpPrefs := make(map[string]any)
+	for k, v := range p.Preferences {
+		cpPrefs[k] = v
+	}
+	cp.Preferences = cpPrefs
+	return &cp, nil
+}
+
+func (m *mockPreferenceRepository) Upsert(ctx context.Context, prefs *domain.UserPreferences) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	cp := *prefs
+	cpPrefs := make(map[string]any)
+	for k, v := range prefs.Preferences {
+		cpPrefs[k] = v
+	}
+	cp.Preferences = cpPrefs
+	m.prefs[prefs.UserID] = &cp
+	return nil
+}
+
+func newTestPreferenceHandler() (*Preference, *mockPreferenceRepository) {
+	repo := newMockPrefRepository()
+	svc := service.NewPreferenceService(repo, logging.Nop())
+	handler := NewPreference(svc, logging.Nop())
+	return handler, repo
+}
+
+func TestPreference_Get(t *testing.T) {
+	handler, repo := newTestPreferenceHandler()
+
+	// Seed data
+	repo.prefs["550e8400-e29b-41d4-a716-446655440000"] = &domain.UserPreferences{
+		UserID:      "550e8400-e29b-41d4-a716-446655440000",
+		Preferences: map[string]any{"theme": "dark"},
+	}
+
+	tests := []struct {
+		name       string
+		userID     string
+		wantStatus int
+		checkBody  func(t *testing.T, body map[string]any)
+	}{
+		{
+			name:       "returns existing preferences",
+			userID:     "550e8400-e29b-41d4-a716-446655440000",
+			wantStatus: http.StatusOK,
+			checkBody: func(t *testing.T, body map[string]any) {
+				data, ok := body["data"].(map[string]any)
+				if !ok {
+					t.Fatal("expected 'data' field in response")
+				}
+				prefs, ok := data["preferences"].(map[string]any)
+				if !ok {
+					t.Fatal("expected 'preferences' field in data")
+				}
+				if prefs["theme"] != "dark" {
+					t.Errorf("expected theme 'dark', got '%v'", prefs["theme"])
+				}
+			},
+		},
+		{
+			name:       "returns empty preferences for unknown user",
+			userID:     "550e8400-e29b-41d4-a716-446655440001",
+			wantStatus: http.StatusOK,
+			checkBody: func(t *testing.T, body map[string]any) {
+				data, ok := body["data"].(map[string]any)
+				if !ok {
+					t.Fatal("expected 'data' field in response")
+				}
+				prefs, ok := data["preferences"].(map[string]any)
+				if !ok {
+					t.Fatal("expected 'preferences' field in data")
+				}
+				if len(prefs) != 0 {
+					t.Errorf("expected empty preferences, got %v", prefs)
+				}
+			},
+		},
+		{
+			name:       "returns 400 for invalid UUID",
+			userID:     "not-a-uuid",
+			wantStatus: http.StatusBadRequest,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := chi.NewRouter()
+			r.Get("/preferences/{user_id}", func(w http.ResponseWriter, r *http.Request) {
+				if err := handler.Get(w, r); err != nil {
+					// Write error status for test verification
+					httpErr, ok := err.(*httperror.HTTPError)
+					if ok {
+						w.WriteHeader(httpErr.Status)
+					} else {
+						w.WriteHeader(http.StatusInternalServerError)
+					}
+					return
+				}
+			})
+
+			req := httptest.NewRequest(http.MethodGet, "/preferences/"+tt.userID, nil)
+			w := httptest.NewRecorder()
+			r.ServeHTTP(w, req)
+
+			if w.Code != tt.wantStatus {
+				t.Errorf("expected status %d, got %d", tt.wantStatus, w.Code)
+			}
+
+			if tt.checkBody != nil && w.Code == http.StatusOK {
+				var body map[string]any
+				if err := json.NewDecoder(w.Body).Decode(&body); err != nil {
+					t.Fatalf("failed to decode response: %v", err)
+				}
+				tt.checkBody(t, body)
+			}
+		})
+	}
+}
+
+func TestPreference_Upsert(t *testing.T) {
+	handler, _ := newTestPreferenceHandler()
+
+	tests := []struct {
+		name       string
+		userID     string
+		body       any
+		wantStatus int
+		checkBody  func(t *testing.T, body map[string]any)
+	}{
+		{
+			name:   "creates preferences successfully",
+			userID: "550e8400-e29b-41d4-a716-446655440000",
+			body: UpdatePreferencesRequest{
+				Preferences: map[string]any{
+					"theme":    "dark",
+					"language": "en",
+				},
+			},
+			wantStatus: http.StatusOK,
+			checkBody: func(t *testing.T, body map[string]any) {
+				data, ok := body["data"].(map[string]any)
+				if !ok {
+					t.Fatal("expected 'data' field in response")
+				}
+				prefs := data["preferences"].(map[string]any)
+				if prefs["theme"] != "dark" {
+					t.Errorf("expected theme 'dark', got '%v'", prefs["theme"])
+				}
+				if data["user_id"] != "550e8400-e29b-41d4-a716-446655440000" {
+					t.Errorf("expected user_id in response, got '%v'", data["user_id"])
+				}
+			},
+		},
+		{
+			name:   "returns 400 for invalid theme",
+			userID: "550e8400-e29b-41d4-a716-446655440000",
+			body: UpdatePreferencesRequest{
+				Preferences: map[string]any{
+					"theme": "neon",
+				},
+			},
+			wantStatus: http.StatusBadRequest,
+		},
+		{
+			name:       "returns 400 for missing preferences field",
+			userID:     "550e8400-e29b-41d4-a716-446655440000",
+			body:       map[string]any{},
+			wantStatus: http.StatusBadRequest,
+		},
+		{
+			name:       "returns 400 for invalid UUID",
+			userID:     "not-a-uuid",
+			body:       UpdatePreferencesRequest{Preferences: map[string]any{"theme": "dark"}},
+			wantStatus: http.StatusBadRequest,
+		},
+		{
+			name:       "returns 400 for empty body",
+			userID:     "550e8400-e29b-41d4-a716-446655440000",
+			body:       nil,
+			wantStatus: http.StatusBadRequest,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := chi.NewRouter()
+			r.Put("/preferences/{user_id}", func(w http.ResponseWriter, r *http.Request) {
+				if err := handler.Upsert(w, r); err != nil {
+					httpErr, ok := err.(*httperror.HTTPError)
+					if ok {
+						w.WriteHeader(httpErr.Status)
+					} else {
+						w.WriteHeader(http.StatusInternalServerError)
+					}
+					return
+				}
+			})
+
+			var bodyBytes []byte
+			if tt.body != nil {
+				var err error
+				bodyBytes, err = json.Marshal(tt.body)
+				if err != nil {
+					t.Fatalf("failed to marshal body: %v", err)
+				}
+			}
+
+			req := httptest.NewRequest(http.MethodPut, "/preferences/"+tt.userID, bytes.NewReader(bodyBytes))
+			req.Header.Set("Content-Type", "application/json")
+			w := httptest.NewRecorder()
+			r.ServeHTTP(w, req)
+
+			if w.Code != tt.wantStatus {
+				t.Errorf("expected status %d, got %d (body: %s)", tt.wantStatus, w.Code, w.Body.String())
+			}
+
+			if tt.checkBody != nil && w.Code == http.StatusOK {
+				var body map[string]any
+				if err := json.NewDecoder(w.Body).Decode(&body); err != nil {
+					t.Fatalf("failed to decode response: %v", err)
+				}
+				tt.checkBody(t, body)
+			}
+		})
+	}
+}

services/preferences-api/internal/api/routes.go

@@ -3,9 +3,7 @@ package api
 
 import (
 	"git.threesix.ai/jordan/slack5-1770606136/pkg/app"
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/auth"
 	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/api/handlers"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/config"
 	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/service"
 )
 
@@ -13,14 +11,13 @@ import (
 // Routes are mounted under /api/preferences-api to match the ingress path routing.
 // This allows the monorepo to expose multiple services under a single domain:
 //   - https://domain/api/preferences-api/health
-//   - https://domain/api/preferences-api/examples
+//   - https://domain/api/preferences-api/preferences/{user_id}
-func RegisterRoutes(application *app.App, exampleService *service.ExampleService) {
+func RegisterRoutes(application *app.App, prefService *service.PreferenceService) {
 	logger := application.Logger()
-	cfg := config.Load()
 
 	// Initialize handlers with injected services
 	healthHandler := handlers.NewHealth(logger)
-	exampleHandler := handlers.NewExample(exampleService, logger)
+	prefHandler := handlers.NewPreference(prefService, logger)
 
 	// Build and mount OpenAPI spec
 	spec := NewServiceSpec()
@@ -31,24 +28,8 @@ func RegisterRoutes(application *app.App, exampleService *service.ExampleService
 	application.Route("/api/preferences-api", func(r app.Router) {
 		r.Get("/health", healthHandler.Check)
 
-		// Public routes (no auth required)
+		// Preference routes (auth out of scope per spec; can be layered on later)
-		r.Get("/examples", app.Wrap(exampleHandler.List))
+		r.Get("/preferences/{user_id}", app.Wrap(prefHandler.Get))
-		r.Get("/examples/{id}", app.Wrap(exampleHandler.Get))
+		r.Put("/preferences/{user_id}", app.Wrap(prefHandler.Upsert))
-
-		// 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: "slack5-1770606136",
-					}),
-				}))
-			}
-
-			r.Post("/examples", app.Wrap(exampleHandler.Create))
-			r.Put("/examples/{id}", app.Wrap(exampleHandler.Update))
-			r.Delete("/examples/{id}", app.Wrap(exampleHandler.Delete))
-		})
 	})
 }

services/preferences-api/internal/api/spec.go

@@ -5,29 +5,20 @@ import "git.threesix.ai/jordan/slack5-1770606136/pkg/openapi"
 // NewServiceSpec builds the OpenAPI specification for the preferences-api service.
 func NewServiceSpec() *openapi.OpenAPISpec {
 	spec := openapi.NewOpenAPISpec("preferences-api API", "1.0.0").
-		WithDescription("REST API for the preferences-api service").
+		WithDescription("REST API for the preferences-api service - manages user preferences").
-		WithBearerSecurity("bearer", "JWT authentication token").
 		WithTag("Health", "Service health endpoints").
-		WithTag("Examples", "Example CRUD endpoints")
+		WithTag("Preferences", "User preference endpoints")
 
 	// Define reusable schemas
-	spec.WithSchema("Example", openapi.Object(map[string]openapi.Schema{
+	spec.WithSchema("UserPreferences", openapi.Object(map[string]openapi.Schema{
-		"id":          openapi.UUID().WithDescription("Unique identifier"),
+		"user_id":     openapi.UUID().WithDescription("User identifier"),
-		"name":        openapi.String().WithDescription("Name of the example").WithExample("My Example"),
+		"preferences": openapi.Object(map[string]openapi.Schema{}).WithDescription("Key-value preference pairs"),
-		"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"))
+	}, "user_id", "preferences", "updated_at"))
 
-	spec.WithSchema("CreateExampleRequest", openapi.Object(map[string]openapi.Schema{
+	spec.WithSchema("UpdatePreferencesRequest", openapi.Object(map[string]openapi.Schema{
-		"name":        openapi.StringWithMinMax(1, 100).WithDescription("Name of the example"),
+		"preferences": openapi.Object(map[string]openapi.Schema{}).WithDescription("Key-value preference pairs to set"),
-		"description": openapi.StringWithMinMax(0, 500).WithDescription("Optional description"),
+	}, "preferences"))
-	}, "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/preferences-api/health", "get", map[string]any{
@@ -41,70 +32,28 @@ func NewServiceSpec() *openapi.OpenAPISpec {
 		},
 	})
 
-	// List examples
+	// Get preferences
-	spec.AddPath("/api/preferences-api/examples", "get", map[string]any{
+	spec.AddPath("/api/preferences-api/preferences/{user_id}", "get", map[string]any{
-		"summary":     "List examples",
+		"summary":     "Get user preferences",
-		"description": "Returns a paginated list of examples.",
+		"description": "Returns all preferences for a user. Returns empty preferences object if user has none.",
-		"tags":        []string{"Examples"},
+		"tags":        []string{"Preferences"},
-		"parameters":  []any{openapi.PageParam(), openapi.PerPageParam()},
+		"parameters":  []any{openapi.PathParam("user_id", "User UUID")},
 		"responses": map[string]any{
-			"200": openapi.OpResponse("Success", openapi.ResponseSchema(openapi.RefArray("Example"))),
+			"200": openapi.OpResponse("Success", openapi.ResponseSchema(openapi.Ref("UserPreferences"))),
+			"400": openapi.OpResponse("Invalid user_id format", openapi.ErrorResponseSchema()),
 		},
 	})
 
-	// Get example
+	// Update preferences
-	spec.AddPath("/api/preferences-api/examples/{id}", "get", map[string]any{
+	spec.AddPath("/api/preferences-api/preferences/{user_id}", "put", map[string]any{
-		"summary":    "Get example by ID",
+		"summary":     "Update user preferences",
-		"tags":       []string{"Examples"},
+		"description": "Creates or updates preferences for a user. Merges with existing preferences.",
-		"parameters": []any{openapi.IDParam()},
+		"tags":        []string{"Preferences"},
+		"parameters":  []any{openapi.PathParam("user_id", "User UUID")},
+		"requestBody": openapi.RequestBody(openapi.Ref("UpdatePreferencesRequest"), true),
 		"responses": map[string]any{
-			"200": openapi.OpResponse("Success", openapi.ResponseSchema(openapi.Ref("Example"))),
+			"200": openapi.OpResponse("Updated", openapi.ResponseSchema(openapi.Ref("UserPreferences"))),
-			"404": openapi.OpResponse("Not found", openapi.ErrorResponseSchema()),
+			"400": openapi.OpResponse("Validation error", openapi.ErrorResponseSchema()),
-		},
-	})
-
-	// Create example
-	spec.AddPath("/api/preferences-api/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/preferences-api/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/preferences-api/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()),
 		},
 	})
 

services/preferences-api/internal/domain/errors.go

@@ -7,15 +7,9 @@ import "errors"
 // Domain errors - these are business-level errors that should be translated
 // to appropriate HTTP status codes by the handler layer.
 var (
-	// ErrNotFound indicates a requested resource does not exist.
+	// ErrInvalidUserID indicates the user ID is invalid.
-	ErrNotFound = errors.New("not found")
+	ErrInvalidUserID = errors.New("invalid user ID")
 
-	// ErrExampleNotFound indicates the requested example does not exist.
+	// ErrInvalidPreferenceValue indicates one or more preference values are invalid.
-	ErrExampleNotFound = errors.New("example not found")
+	ErrInvalidPreferenceValue = errors.New("invalid preference value")
-
-	// ErrDuplicateExample indicates an example with the same name already exists.
-	ErrDuplicateExample = errors.New("example with this name already exists")
-
-	// ErrInvalidExampleName indicates the example name is invalid.
-	ErrInvalidExampleName = errors.New("invalid example name")
 )

services/preferences-api/internal/domain/example.go

@@ -1,89 +0,0 @@
-package domain
-
-import (
-	"time"
-	"unicode/utf8"
-)
-
-// ExampleID is a strongly-typed identifier for examples.
-type ExampleID string
-
-// String returns the string representation of the ID.
-func (id ExampleID) String() string {
-	return string(id)
-}
-
-// IsZero returns true if the ID is empty.
-func (id ExampleID) IsZero() bool {
-	return id == ""
-}
-
-// Example name constraints.
-const (
-	MinExampleNameLen = 1
-	MaxExampleNameLen = 100
-	MaxDescriptionLen = 500
-)
-
-// Example represents an example domain entity.
-// This is a pure domain model with no external dependencies.
-type Example struct {
-	ID          ExampleID
-	Name        string
-	Description string
-	CreatedAt   time.Time
-	UpdatedAt   time.Time
-}
-
-// NewExample creates a new Example with validation.
-// Returns ErrInvalidExampleName if the name is invalid.
-func NewExample(id ExampleID, name, description string) (*Example, error) {
-	if err := validateExampleName(name); err != nil {
-		return nil, err
-	}
-	if err := validateDescription(description); err != nil {
-		return nil, err
-	}
-
-	now := time.Now().UTC()
-	return &Example{
-		ID:          id,
-		Name:        name,
-		Description: description,
-		CreatedAt:   now,
-		UpdatedAt:   now,
-	}, nil
-}
-
-// Update modifies the example's mutable fields with validation.
-// Returns ErrInvalidExampleName if the name is invalid.
-func (e *Example) Update(name, description string) error {
-	if err := validateExampleName(name); err != nil {
-		return err
-	}
-	if err := validateDescription(description); err != nil {
-		return err
-	}
-
-	e.Name = name
-	e.Description = description
-	e.UpdatedAt = time.Now().UTC()
-	return nil
-}
-
-// validateExampleName validates an example name.
-func validateExampleName(name string) error {
-	length := utf8.RuneCountInString(name)
-	if length < MinExampleNameLen || length > MaxExampleNameLen {
-		return ErrInvalidExampleName
-	}
-	return nil
-}
-
-// validateDescription validates a description.
-func validateDescription(desc string) error {
-	if utf8.RuneCountInString(desc) > MaxDescriptionLen {
-		return ErrInvalidExampleName
-	}
-	return nil
-}

services/preferences-api/internal/domain/preference.go

@@ -0,0 +1,11 @@
+package domain
+
+import "time"
+
+// UserPreferences represents a user's stored preferences.
+type UserPreferences struct {
+	UserID      string
+	Preferences map[string]any
+	CreatedAt   time.Time
+	UpdatedAt   time.Time
+}

services/preferences-api/internal/port/example.go

@@ -1,37 +0,0 @@
-// Package port defines interfaces (ports) for external dependencies.
-// These interfaces define the contracts between the application core and
-// infrastructure adapters, enabling testability and flexibility.
-package port
-
-import (
-	"context"
-
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
-)
-
-// ExampleRepository defines the interface for example persistence operations.
-// Implementations may use databases, in-memory storage, or external services.
-type ExampleRepository interface {
-	// List returns all examples.
-	List(ctx context.Context) ([]domain.Example, error)
-
-	// Get returns an example by ID.
-	// Returns domain.ErrExampleNotFound if not found.
-	Get(ctx context.Context, id domain.ExampleID) (*domain.Example, error)
-
-	// Create stores a new example.
-	// The example must have a valid ID set.
-	Create(ctx context.Context, example *domain.Example) error
-
-	// Update modifies an existing example.
-	// Returns domain.ErrExampleNotFound if not found.
-	Update(ctx context.Context, example *domain.Example) error
-
-	// Delete removes an example by ID.
-	// Returns domain.ErrExampleNotFound if not found.
-	Delete(ctx context.Context, id domain.ExampleID) error
-
-	// ExistsByName checks if an example with the given name exists.
-	// Used for duplicate detection.
-	ExistsByName(ctx context.Context, name string) (bool, error)
-}

services/preferences-api/internal/port/preference.go

@@ -0,0 +1,18 @@
+package port
+
+import (
+	"context"
+
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
+)
+
+// PreferenceRepository defines the interface for preference persistence operations.
+type PreferenceRepository interface {
+	// Get returns preferences for a user.
+	// Returns nil, nil when no row exists for the given userID.
+	Get(ctx context.Context, userID string) (*domain.UserPreferences, error)
+
+	// Upsert creates or updates preferences for a user.
+	// Uses ON CONFLICT to handle both insert and update atomically.
+	Upsert(ctx context.Context, prefs *domain.UserPreferences) error
+}

services/preferences-api/internal/service/example.go

@@ -1,137 +0,0 @@
-// Package service provides business logic / use cases for the application.
-// Services orchestrate domain operations using port interfaces.
-package service
-
-import (
-	"context"
-	"errors"
-
-	"github.com/google/uuid"
-
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
-)
-
-// ExampleService handles example-related business logic.
-type ExampleService struct {
-	repo   port.ExampleRepository
-	logger *logging.Logger
-}
-
-// NewExampleService creates a new example service.
-func NewExampleService(repo port.ExampleRepository, logger *logging.Logger) *ExampleService {
-	return &ExampleService{
-		repo:   repo,
-		logger: logger.WithService("ExampleService"),
-	}
-}
-
-// List returns all examples.
-func (s *ExampleService) List(ctx context.Context) ([]domain.Example, error) {
-	return s.repo.List(ctx)
-}
-
-// Get returns an example by ID.
-// Returns domain.ErrExampleNotFound if not found.
-func (s *ExampleService) Get(ctx context.Context, id domain.ExampleID) (*domain.Example, error) {
-	return s.repo.Get(ctx, id)
-}
-
-// CreateInput contains the data needed to create an example.
-type CreateInput struct {
-	Name        string
-	Description string
-}
-
-// Create creates a new example with duplicate detection.
-// Returns domain.ErrDuplicateExample if name already exists.
-// Returns domain.ErrInvalidExampleName if name is invalid.
-func (s *ExampleService) Create(ctx context.Context, input CreateInput) (*domain.Example, error) {
-	// Check for duplicates
-	exists, err := s.repo.ExistsByName(ctx, input.Name)
-	if err != nil {
-		return nil, err
-	}
-	if exists {
-		return nil, domain.ErrDuplicateExample
-	}
-
-	// Generate new ID
-	id := domain.ExampleID(uuid.New().String())
-
-	// Create domain entity (validates name)
-	example, err := domain.NewExample(id, input.Name, input.Description)
-	if err != nil {
-		return nil, err
-	}
-
-	// Persist
-	if err := s.repo.Create(ctx, example); err != nil {
-		return nil, err
-	}
-
-	s.logger.Info("example created", "id", id, "name", input.Name)
-	return example, nil
-}
-
-// UpdateInput contains the data needed to update an example.
-type UpdateInput struct {
-	Name        string
-	Description string
-}
-
-// Update modifies an existing example.
-// Returns domain.ErrExampleNotFound if not found.
-// Returns domain.ErrDuplicateExample if new name conflicts with another example.
-// Returns domain.ErrInvalidExampleName if name is invalid.
-func (s *ExampleService) Update(ctx context.Context, id domain.ExampleID, input UpdateInput) (*domain.Example, error) {
-	// Fetch existing
-	example, err := s.repo.Get(ctx, id)
-	if err != nil {
-		return nil, err
-	}
-
-	// Check for name conflicts (only if name changed)
-	if example.Name != input.Name {
-		exists, err := s.repo.ExistsByName(ctx, input.Name)
-		if err != nil {
-			return nil, err
-		}
-		if exists {
-			return nil, domain.ErrDuplicateExample
-		}
-	}
-
-	// Update domain entity (validates name)
-	if err := example.Update(input.Name, input.Description); err != nil {
-		return nil, err
-	}
-
-	// Persist
-	if err := s.repo.Update(ctx, example); err != nil {
-		return nil, err
-	}
-
-	s.logger.Info("example updated", "id", id, "name", input.Name)
-	return example, nil
-}
-
-// Delete removes an example by ID.
-// Returns domain.ErrExampleNotFound if not found.
-func (s *ExampleService) Delete(ctx context.Context, id domain.ExampleID) error {
-	// Verify exists before delete
-	if _, err := s.repo.Get(ctx, id); err != nil {
-		if errors.Is(err, domain.ErrExampleNotFound) {
-			return domain.ErrExampleNotFound
-		}
-		return err
-	}
-
-	if err := s.repo.Delete(ctx, id); err != nil {
-		return err
-	}
-
-	s.logger.Info("example deleted", "id", id)
-	return nil
-}

services/preferences-api/internal/service/example_test.go

@@ -1,282 +0,0 @@
-package service
-
-import (
-	"context"
-	"sync"
-	"testing"
-
-	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
-	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
-)
-
-// mockExampleRepository implements port.ExampleRepository for testing.
-type mockExampleRepository struct {
-	mu       sync.RWMutex
-	examples map[domain.ExampleID]*domain.Example
-}
-
-var _ port.ExampleRepository = (*mockExampleRepository)(nil)
-
-func newMockExampleRepository() *mockExampleRepository {
-	return &mockExampleRepository{
-		examples: make(map[domain.ExampleID]*domain.Example),
-	}
-}
-
-func (m *mockExampleRepository) List(ctx context.Context) ([]domain.Example, error) {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-
-	result := make([]domain.Example, 0, len(m.examples))
-	for _, e := range m.examples {
-		result = append(result, *e)
-	}
-	return result, nil
-}
-
-func (m *mockExampleRepository) Get(ctx context.Context, id domain.ExampleID) (*domain.Example, error) {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-
-	e, ok := m.examples[id]
-	if !ok {
-		return nil, domain.ErrExampleNotFound
-	}
-	// Return a copy to avoid mutation
-	copy := *e
-	return &copy, nil
-}
-
-func (m *mockExampleRepository) Create(ctx context.Context, example *domain.Example) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	// Store a copy
-	copy := *example
-	m.examples[example.ID] = &copy
-	return nil
-}
-
-func (m *mockExampleRepository) Update(ctx context.Context, example *domain.Example) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if _, ok := m.examples[example.ID]; !ok {
-		return domain.ErrExampleNotFound
-	}
-	// Store a copy
-	copy := *example
-	m.examples[example.ID] = &copy
-	return nil
-}
-
-func (m *mockExampleRepository) Delete(ctx context.Context, id domain.ExampleID) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if _, ok := m.examples[id]; !ok {
-		return domain.ErrExampleNotFound
-	}
-	delete(m.examples, id)
-	return nil
-}
-
-func (m *mockExampleRepository) ExistsByName(ctx context.Context, name string) (bool, error) {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-
-	for _, e := range m.examples {
-		if e.Name == name {
-			return true, nil
-		}
-	}
-	return false, nil
-}
-
-func TestExampleService_Create(t *testing.T) {
-	repo := newMockExampleRepository()
-	svc := NewExampleService(repo, logging.Nop())
-
-	t.Run("creates example successfully", func(t *testing.T) {
-		example, err := svc.Create(context.Background(), CreateInput{
-			Name:        "Test Example",
-			Description: "A test description",
-		})
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
-		if example.Name != "Test Example" {
-			t.Errorf("expected name 'Test Example', got '%s'", example.Name)
-		}
-		if example.ID.IsZero() {
-			t.Error("expected non-empty ID")
-		}
-	})
-
-	t.Run("rejects duplicate name", func(t *testing.T) {
-		_, err := svc.Create(context.Background(), CreateInput{
-			Name:        "Test Example",
-			Description: "Another description",
-		})
-		if err != domain.ErrDuplicateExample {
-			t.Errorf("expected ErrDuplicateExample, got %v", err)
-		}
-	})
-
-	t.Run("rejects empty name", func(t *testing.T) {
-		_, err := svc.Create(context.Background(), CreateInput{
-			Name:        "",
-			Description: "Description",
-		})
-		if err != domain.ErrInvalidExampleName {
-			t.Errorf("expected ErrInvalidExampleName, got %v", err)
-		}
-	})
-}
-
-func TestExampleService_Get(t *testing.T) {
-	repo := newMockExampleRepository()
-	svc := NewExampleService(repo, logging.Nop())
-
-	// Create an example first
-	created, _ := svc.Create(context.Background(), CreateInput{
-		Name:        "Get Test",
-		Description: "Description",
-	})
-
-	t.Run("returns existing example", func(t *testing.T) {
-		example, err := svc.Get(context.Background(), created.ID)
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
-		if example.Name != "Get Test" {
-			t.Errorf("expected name 'Get Test', got '%s'", example.Name)
-		}
-	})
-
-	t.Run("returns not found for missing example", func(t *testing.T) {
-		_, err := svc.Get(context.Background(), "nonexistent-id")
-		if err != domain.ErrExampleNotFound {
-			t.Errorf("expected ErrExampleNotFound, got %v", err)
-		}
-	})
-}
-
-func TestExampleService_Update(t *testing.T) {
-	repo := newMockExampleRepository()
-	svc := NewExampleService(repo, logging.Nop())
-
-	// Create examples
-	example1, _ := svc.Create(context.Background(), CreateInput{
-		Name:        "Update Test 1",
-		Description: "Original",
-	})
-	_, _ = svc.Create(context.Background(), CreateInput{
-		Name:        "Update Test 2",
-		Description: "Other",
-	})
-
-	t.Run("updates example successfully", func(t *testing.T) {
-		updated, err := svc.Update(context.Background(), example1.ID, UpdateInput{
-			Name:        "Updated Name",
-			Description: "Updated description",
-		})
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
-		if updated.Name != "Updated Name" {
-			t.Errorf("expected name 'Updated Name', got '%s'", updated.Name)
-		}
-	})
-
-	t.Run("allows same name on same example", func(t *testing.T) {
-		_, err := svc.Update(context.Background(), example1.ID, UpdateInput{
-			Name:        "Updated Name",
-			Description: "Same name",
-		})
-		if err != nil {
-			t.Errorf("unexpected error updating with same name: %v", err)
-		}
-	})
-
-	t.Run("rejects name conflict", func(t *testing.T) {
-		_, err := svc.Update(context.Background(), example1.ID, UpdateInput{
-			Name:        "Update Test 2",
-			Description: "Conflict",
-		})
-		if err != domain.ErrDuplicateExample {
-			t.Errorf("expected ErrDuplicateExample, got %v", err)
-		}
-	})
-
-	t.Run("returns not found for missing example", func(t *testing.T) {
-		_, err := svc.Update(context.Background(), "nonexistent-id", UpdateInput{
-			Name:        "Anything",
-			Description: "",
-		})
-		if err != domain.ErrExampleNotFound {
-			t.Errorf("expected ErrExampleNotFound, got %v", err)
-		}
-	})
-}
-
-func TestExampleService_Delete(t *testing.T) {
-	repo := newMockExampleRepository()
-	svc := NewExampleService(repo, logging.Nop())
-
-	// Create an example first
-	created, _ := svc.Create(context.Background(), CreateInput{
-		Name:        "Delete Test",
-		Description: "To be deleted",
-	})
-
-	t.Run("deletes example successfully", func(t *testing.T) {
-		err := svc.Delete(context.Background(), created.ID)
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
-
-		// Verify deleted
-		_, err = svc.Get(context.Background(), created.ID)
-		if err != domain.ErrExampleNotFound {
-			t.Errorf("expected ErrExampleNotFound after delete, got %v", err)
-		}
-	})
-
-	t.Run("returns not found for missing example", func(t *testing.T) {
-		err := svc.Delete(context.Background(), "nonexistent-id")
-		if err != domain.ErrExampleNotFound {
-			t.Errorf("expected ErrExampleNotFound, got %v", err)
-		}
-	})
-}
-
-func TestExampleService_List(t *testing.T) {
-	repo := newMockExampleRepository()
-	svc := NewExampleService(repo, logging.Nop())
-
-	t.Run("returns empty list initially", func(t *testing.T) {
-		examples, err := svc.List(context.Background())
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
-		if len(examples) != 0 {
-			t.Errorf("expected 0 examples, got %d", len(examples))
-		}
-	})
-
-	// Create some examples
-	_, _ = svc.Create(context.Background(), CreateInput{Name: "List Test 1", Description: ""})
-	_, _ = svc.Create(context.Background(), CreateInput{Name: "List Test 2", Description: ""})
-
-	t.Run("returns all examples", func(t *testing.T) {
-		examples, err := svc.List(context.Background())
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
-		if len(examples) != 2 {
-			t.Errorf("expected 2 examples, got %d", len(examples))
-		}
-	})
-}

services/preferences-api/internal/service/preference.go

@@ -0,0 +1,133 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"golang.org/x/text/language"
+
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
+)
+
+// ValidationError carries per-field validation details.
+// It wraps domain.ErrInvalidPreferenceValue for errors.Is() matching.
+type ValidationError struct {
+	Details map[string]string
+}
+
+func (e *ValidationError) Error() string { return "invalid preference values" }
+func (e *ValidationError) Unwrap() error { return domain.ErrInvalidPreferenceValue }
+
+// validThemes is the set of allowed values for the "theme" preference.
+var validThemes = map[string]bool{
+	"light":  true,
+	"dark":   true,
+	"system": true,
+}
+
+// PreferenceService handles preference-related business logic.
+type PreferenceService struct {
+	repo   port.PreferenceRepository
+	logger *logging.Logger
+}
+
+// NewPreferenceService creates a new preference service.
+func NewPreferenceService(repo port.PreferenceRepository, logger *logging.Logger) *PreferenceService {
+	return &PreferenceService{
+		repo:   repo,
+		logger: logger.WithService("PreferenceService"),
+	}
+}
+
+// Get returns preferences for a user.
+// Returns nil when no preferences exist.
+func (s *PreferenceService) Get(ctx context.Context, userID string) (*domain.UserPreferences, error) {
+	return s.repo.Get(ctx, userID)
+}
+
+// UpsertInput contains the data needed to upsert preferences.
+type UpsertInput struct {
+	UserID      string
+	Preferences map[string]any
+}
+
+// Upsert validates and stores preferences for a user.
+// Known keys are validated; unknown keys are accepted as-is.
+// Incoming keys are merged on top of existing preferences.
+func (s *PreferenceService) Upsert(ctx context.Context, input UpsertInput) (*domain.UserPreferences, error) {
+	// Validate known preference keys
+	if err := validatePreferences(input.Preferences); err != nil {
+		return nil, err
+	}
+
+	// Fetch existing preferences for merge
+	existing, err := s.repo.Get(ctx, input.UserID)
+	if err != nil {
+		return nil, err
+	}
+
+	merged := make(map[string]any)
+	if existing != nil {
+		for k, v := range existing.Preferences {
+			merged[k] = v
+		}
+	}
+	for k, v := range input.Preferences {
+		merged[k] = v
+	}
+
+	now := time.Now().UTC()
+	prefs := &domain.UserPreferences{
+		UserID:      input.UserID,
+		Preferences: merged,
+		UpdatedAt:   now,
+	}
+	if existing != nil {
+		prefs.CreatedAt = existing.CreatedAt
+	} else {
+		prefs.CreatedAt = now
+	}
+
+	if err := s.repo.Upsert(ctx, prefs); err != nil {
+		return nil, err
+	}
+
+	s.logger.Info("preferences upserted", "user_id", input.UserID)
+	return prefs, nil
+}
+
+// validatePreferences checks known preference keys against their allowed values.
+func validatePreferences(prefs map[string]any) error {
+	details := make(map[string]string)
+
+	for key, value := range prefs {
+		switch key {
+		case "theme":
+			s, ok := value.(string)
+			if !ok || !validThemes[s] {
+				details[key] = "must be one of: light, dark, system"
+			}
+		case "language":
+			s, ok := value.(string)
+			if !ok {
+				details[key] = "must be a valid BCP-47 language tag"
+				continue
+			}
+			if _, err := language.Parse(s); err != nil {
+				details[key] = fmt.Sprintf("must be a valid BCP-47 language tag")
+			}
+		case "notifications_enabled":
+			if _, ok := value.(bool); !ok {
+				details[key] = "must be a boolean"
+			}
+		}
+	}
+
+	if len(details) > 0 {
+		return &ValidationError{Details: details}
+	}
+	return nil
+}

services/preferences-api/internal/service/preference_test.go

@@ -0,0 +1,268 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"testing"
+
+	"git.threesix.ai/jordan/slack5-1770606136/pkg/logging"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/domain"
+	"git.threesix.ai/jordan/slack5-1770606136/services/preferences-api/internal/port"
+)
+
+// mockPreferenceRepository implements port.PreferenceRepository for testing.
+type mockPreferenceRepository struct {
+	mu    sync.RWMutex
+	prefs map[string]*domain.UserPreferences
+}
+
+var _ port.PreferenceRepository = (*mockPreferenceRepository)(nil)
+
+func newMockPreferenceRepository() *mockPreferenceRepository {
+	return &mockPreferenceRepository{
+		prefs: make(map[string]*domain.UserPreferences),
+	}
+}
+
+func (m *mockPreferenceRepository) Get(ctx context.Context, userID string) (*domain.UserPreferences, error) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+
+	p, ok := m.prefs[userID]
+	if !ok {
+		return nil, nil
+	}
+	// Return a copy
+	cp := *p
+	cpPrefs := make(map[string]any)
+	for k, v := range p.Preferences {
+		cpPrefs[k] = v
+	}
+	cp.Preferences = cpPrefs
+	return &cp, nil
+}
+
+func (m *mockPreferenceRepository) Upsert(ctx context.Context, prefs *domain.UserPreferences) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	cp := *prefs
+	cpPrefs := make(map[string]any)
+	for k, v := range prefs.Preferences {
+		cpPrefs[k] = v
+	}
+	cp.Preferences = cpPrefs
+	m.prefs[prefs.UserID] = &cp
+	return nil
+}
+
+func TestPreferenceService_Get(t *testing.T) {
+	repo := newMockPreferenceRepository()
+	svc := NewPreferenceService(repo, logging.Nop())
+
+	t.Run("returns nil for non-existent user", func(t *testing.T) {
+		result, err := svc.Get(context.Background(), "user-1")
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if result != nil {
+			t.Error("expected nil result for non-existent user")
+		}
+	})
+
+	t.Run("returns existing preferences", func(t *testing.T) {
+		_, _ = svc.Upsert(context.Background(), UpsertInput{
+			UserID:      "user-2",
+			Preferences: map[string]any{"theme": "dark"},
+		})
+
+		result, err := svc.Get(context.Background(), "user-2")
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if result == nil {
+			t.Fatal("expected non-nil result")
+		}
+		if result.Preferences["theme"] != "dark" {
+			t.Errorf("expected theme 'dark', got '%v'", result.Preferences["theme"])
+		}
+	})
+}
+
+func TestPreferenceService_Upsert(t *testing.T) {
+	repo := newMockPreferenceRepository()
+	svc := NewPreferenceService(repo, logging.Nop())
+
+	t.Run("creates preferences for new user", func(t *testing.T) {
+		result, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-1",
+			Preferences: map[string]any{
+				"theme":    "dark",
+				"language": "en",
+			},
+		})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if result.Preferences["theme"] != "dark" {
+			t.Errorf("expected theme 'dark', got '%v'", result.Preferences["theme"])
+		}
+		if result.Preferences["language"] != "en" {
+			t.Errorf("expected language 'en', got '%v'", result.Preferences["language"])
+		}
+	})
+
+	t.Run("merges preferences with existing", func(t *testing.T) {
+		result, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-1",
+			Preferences: map[string]any{
+				"notifications_enabled": true,
+			},
+		})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		// Existing keys should be preserved
+		if result.Preferences["theme"] != "dark" {
+			t.Errorf("expected theme 'dark' preserved, got '%v'", result.Preferences["theme"])
+		}
+		if result.Preferences["language"] != "en" {
+			t.Errorf("expected language 'en' preserved, got '%v'", result.Preferences["language"])
+		}
+		// New key should be added
+		if result.Preferences["notifications_enabled"] != true {
+			t.Errorf("expected notifications_enabled true, got '%v'", result.Preferences["notifications_enabled"])
+		}
+	})
+
+	t.Run("overwrites existing key", func(t *testing.T) {
+		result, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-1",
+			Preferences: map[string]any{
+				"theme": "light",
+			},
+		})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if result.Preferences["theme"] != "light" {
+			t.Errorf("expected theme 'light', got '%v'", result.Preferences["theme"])
+		}
+		// Other keys preserved
+		if result.Preferences["language"] != "en" {
+			t.Errorf("expected language 'en' preserved, got '%v'", result.Preferences["language"])
+		}
+	})
+
+	t.Run("accepts unknown keys without validation", func(t *testing.T) {
+		result, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-2",
+			Preferences: map[string]any{
+				"custom_setting": "anything",
+				"sidebar_width":  42.0,
+			},
+		})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if result.Preferences["custom_setting"] != "anything" {
+			t.Errorf("expected custom_setting 'anything', got '%v'", result.Preferences["custom_setting"])
+		}
+	})
+
+	t.Run("rejects invalid theme", func(t *testing.T) {
+		_, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-3",
+			Preferences: map[string]any{
+				"theme": "neon",
+			},
+		})
+		if err == nil {
+			t.Fatal("expected error for invalid theme")
+		}
+		if !errors.Is(err, domain.ErrInvalidPreferenceValue) {
+			t.Errorf("expected ErrInvalidPreferenceValue, got %v", err)
+		}
+		var valErr *ValidationError
+		if !errors.As(err, &valErr) {
+			t.Fatal("expected ValidationError type")
+		}
+		if valErr.Details["theme"] == "" {
+			t.Error("expected details for theme key")
+		}
+	})
+
+	t.Run("rejects invalid language", func(t *testing.T) {
+		_, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-3",
+			Preferences: map[string]any{
+				"language": "not-a-language-!!!",
+			},
+		})
+		if err == nil {
+			t.Fatal("expected error for invalid language")
+		}
+		var valErr *ValidationError
+		if !errors.As(err, &valErr) {
+			t.Fatal("expected ValidationError type")
+		}
+		if valErr.Details["language"] == "" {
+			t.Error("expected details for language key")
+		}
+	})
+
+	t.Run("rejects non-boolean notifications_enabled", func(t *testing.T) {
+		_, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-3",
+			Preferences: map[string]any{
+				"notifications_enabled": "yes",
+			},
+		})
+		if err == nil {
+			t.Fatal("expected error for non-boolean notifications_enabled")
+		}
+		var valErr *ValidationError
+		if !errors.As(err, &valErr) {
+			t.Fatal("expected ValidationError type")
+		}
+		if valErr.Details["notifications_enabled"] == "" {
+			t.Error("expected details for notifications_enabled key")
+		}
+	})
+
+	t.Run("collects multiple validation errors", func(t *testing.T) {
+		_, err := svc.Upsert(context.Background(), UpsertInput{
+			UserID: "user-3",
+			Preferences: map[string]any{
+				"theme":                 "invalid",
+				"notifications_enabled": "not-bool",
+			},
+		})
+		if err == nil {
+			t.Fatal("expected error for multiple invalid values")
+		}
+		var valErr *ValidationError
+		if !errors.As(err, &valErr) {
+			t.Fatal("expected ValidationError type")
+		}
+		if len(valErr.Details) != 2 {
+			t.Errorf("expected 2 validation errors, got %d", len(valErr.Details))
+		}
+	})
+
+	t.Run("accepts valid BCP-47 tags", func(t *testing.T) {
+		validTags := []string{"en", "fr", "es", "de", "ja", "zh-Hans", "pt-BR"}
+		for _, tag := range validTags {
+			_, err := svc.Upsert(context.Background(), UpsertInput{
+				UserID: "user-lang-" + tag,
+				Preferences: map[string]any{
+					"language": tag,
+				},
+			})
+			if err != nil {
+				t.Errorf("expected no error for valid BCP-47 tag '%s', got %v", tag, err)
+			}
+		}
+	})
+}