diff --git a/internal/adapter/postgres/build_audit.go b/internal/adapter/postgres/build_audit.go
index 6dcfcdc..2f974af 100644
--- a/internal/adapter/postgres/build_audit.go
+++ b/internal/adapter/postgres/build_audit.go
@@ -83,6 +83,28 @@ func (r *BuildAuditRepository) Update(ctx context.Context, taskID string, result
 	return nil
 }
 
+// UpdateStatus updates the status and worker assignment when a task is claimed.
+func (r *BuildAuditRepository) UpdateStatus(ctx context.Context, taskID string, status domain.BuildStatus, workerID string) error {
+	res, err := r.db.ExecContext(ctx, `
+		UPDATE build_audit
+		SET status = $2, worker_id = $3
+		WHERE task_id = $1
+	`, taskID, status, nullString(workerID))
+	if err != nil {
+		return fmt.Errorf("update build audit status: %w", err)
+	}
+
+	rows, err := res.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("rows affected: %w", err)
+	}
+	if rows == 0 {
+		return domain.ErrBuildNotFound
+	}
+
+	return nil
+}
+
 // Get retrieves a specific audit entry by task ID.
 func (r *BuildAuditRepository) Get(ctx context.Context, taskID string) (*domain.BuildAuditEntry, error) {
 	rows, err := r.db.QueryContext(ctx, `
diff --git a/internal/adapter/postgres/build_audit_test.go b/internal/adapter/postgres/build_audit_test.go
index cb2818e..19866ad 100644
--- a/internal/adapter/postgres/build_audit_test.go
+++ b/internal/adapter/postgres/build_audit_test.go
@@ -181,6 +181,83 @@ func TestBuildAuditRepository_Update(t *testing.T) {
 	})
 }
 
+func TestBuildAuditRepository_UpdateStatus(t *testing.T) {
+	db := testutil.TestDB(t)
+	t.Cleanup(func() { cleanupTestBuildAudit(t, db) })
+
+	repo := NewBuildAuditRepository(db)
+	ctx := context.Background()
+
+	// Create initial entry
+	entry := &domain.BuildAuditEntry{
+		TaskID:    "test-task-status-1",
+		ProjectID: "test-project-1",
+		Spec:      domain.BuildSpec{Prompt: "Build"},
+		Status:    domain.BuildStatusPending,
+		StartedAt: time.Now(),
+	}
+	if err := repo.Record(ctx, entry); err != nil {
+		t.Fatalf("Record() error = %v", err)
+	}
+
+	t.Run("updates status and worker ID", func(t *testing.T) {
+		err := repo.UpdateStatus(ctx, "test-task-status-1", domain.BuildStatusRunning, "worker-123")
+		if err != nil {
+			t.Fatalf("UpdateStatus() error = %v", err)
+		}
+
+		got, err := repo.Get(ctx, "test-task-status-1")
+		if err != nil {
+			t.Fatalf("Get() error = %v", err)
+		}
+		if got.Status != domain.BuildStatusRunning {
+			t.Errorf("got status %q, want %q", got.Status, domain.BuildStatusRunning)
+		}
+		if got.WorkerID != "worker-123" {
+			t.Errorf("got worker_id %q, want %q", got.WorkerID, "worker-123")
+		}
+	})
+
+	t.Run("updates status with empty worker ID", func(t *testing.T) {
+		// Create another entry
+		entry := &domain.BuildAuditEntry{
+			TaskID:    "test-task-status-2",
+			ProjectID: "test-project-1",
+			WorkerID:  "old-worker",
+			Spec:      domain.BuildSpec{Prompt: "Build"},
+			Status:    domain.BuildStatusRunning,
+			StartedAt: time.Now(),
+		}
+		if err := repo.Record(ctx, entry); err != nil {
+			t.Fatalf("Record() error = %v", err)
+		}
+
+		err := repo.UpdateStatus(ctx, "test-task-status-2", domain.BuildStatusCompleted, "")
+		if err != nil {
+			t.Fatalf("UpdateStatus() error = %v", err)
+		}
+
+		got, err := repo.Get(ctx, "test-task-status-2")
+		if err != nil {
+			t.Fatalf("Get() error = %v", err)
+		}
+		if got.Status != domain.BuildStatusCompleted {
+			t.Errorf("got status %q, want %q", got.Status, domain.BuildStatusCompleted)
+		}
+		// WorkerID should be cleared when empty string is passed
+		if got.WorkerID != "" {
+			t.Errorf("got worker_id %q, want empty", got.WorkerID)
+		}
+	})
+
+	t.Run("returns error for nonexistent task", func(t *testing.T) {
+		err := repo.UpdateStatus(ctx, "test-task-nonexistent", domain.BuildStatusRunning, "worker-1")
+		if err == nil {
+			t.Error("expected error for nonexistent task")
+		}
+	})
+}
+
 func TestBuildAuditRepository_Get(t *testing.T) {
 	db := testutil.TestDB(t)
 	t.Cleanup(func() { cleanupTestBuildAudit(t, db) })
diff --git a/internal/handlers/builds_test.go b/internal/handlers/builds_test.go
index 8a2073c..241a698 100644
--- a/internal/handlers/builds_test.go
+++ b/internal/handlers/builds_test.go
@@ -66,6 +66,19 @@ func (m *mockBuildAudit) Update(_ context.Context, taskID string, result *domain
 	return nil
 }
 
+func (m *mockBuildAudit) UpdateStatus(_ context.Context, taskID string, status domain.BuildStatus, workerID string) error {
+	if m.err != nil {
+		return m.err
+	}
+	entry, ok := m.entries[taskID]
+	if !ok {
+		return domain.ErrBuildNotFound
+	}
+	entry.Status = status
+	entry.WorkerID = workerID
+	return nil
+}
+
 func (m *mockBuildAudit) Get(_ context.Context, taskID string) (*domain.BuildAuditEntry, error) {
 	if m.err != nil {
 		return nil, m.err
diff --git a/internal/port/build_audit.go b/internal/port/build_audit.go
index c248861..9211b17 100644
--- a/internal/port/build_audit.go
+++ b/internal/port/build_audit.go
@@ -19,6 +19,10 @@ type BuildAudit interface {
 	// Update modifies an existing entry when a build completes.
 	Update(ctx context.Context, taskID string, result *domain.BuildResult) error
 
+	// UpdateStatus updates the status and worker assignment when a task is claimed.
+	// This is called when a worker picks up a task to mark it as running.
+	UpdateStatus(ctx context.Context, taskID string, status domain.BuildStatus, workerID string) error
+
 	// Get retrieves a specific audit entry by task ID.
 	// Returns ErrBuildNotFound if the entry does not exist.
 	Get(ctx context.Context, taskID string) (*domain.BuildAuditEntry, error)
diff --git a/internal/service/mock_test.go b/internal/service/mock_test.go
index ce44967..ddf7363 100644
--- a/internal/service/mock_test.go
+++ b/internal/service/mock_test.go
@@ -130,6 +130,19 @@ func (m *mockBuildAudit) Update(ctx context.Context, taskID string, result *doma
 	return nil
 }
 
+func (m *mockBuildAudit) UpdateStatus(ctx context.Context, taskID string, status domain.BuildStatus, workerID string) error {
+	if m.err != nil {
+		return m.err
+	}
+	entry, ok := m.entries[taskID]
+	if !ok {
+		return domain.ErrBuildNotFound
+	}
+	entry.Status = status
+	entry.WorkerID = workerID
+	return nil
+}
+
 func (m *mockBuildAudit) Get(ctx context.Context, taskID string) (*domain.BuildAuditEntry, error) {
 	if m.err != nil {
 		return nil, m.err
diff --git a/internal/service/worker_service.go b/internal/service/worker_service.go
index 450a027..7316ae2 100644
--- a/internal/service/worker_service.go
+++ b/internal/service/worker_service.go
@@ -118,12 +118,14 @@ func (s *WorkerService) ClaimTask(ctx context.Context, workerID string) (*domain
 		)
 	}
 
-	// Update audit entry if available
+	// Update audit entry if available - persist status change to database
 	if s.audit != nil {
-		entry, _ := s.audit.Get(ctx, task.ID)
-		if entry != nil {
-			entry.WorkerID = workerID
-			entry.Status = domain.BuildStatusRunning
+		if err := s.audit.UpdateStatus(ctx, task.ID, domain.BuildStatusRunning, workerID); err != nil {
+			s.logger.Warn("failed to update audit status after claim",
+				"task_id", task.ID,
+				"worker_id", workerID,
+				"error", err,
+			)
 		}
 	}
 
diff --git a/internal/service/worker_service_test.go b/internal/service/worker_service_test.go
index 5ae8bad..1e728fb 100644
--- a/internal/service/worker_service_test.go
+++ b/internal/service/worker_service_test.go
@@ -174,6 +174,50 @@ func TestWorkerService_ClaimTask(t *testing.T) {
 			t.Error("expected nil task when queue is empty")
 		}
 	})
+
+	t.Run("updates audit status when claiming task", func(t *testing.T) {
+		registry := newMockWorkerRegistry()
+		registry.workers["worker-1"] = &domain.Worker{
+			ID:       "worker-1",
+			Hostname: "host-1",
+			Status:   domain.WorkerStatusIdle,
+		}
+
+		queue := newMockWorkQueue()
+		queue.tasks["task-1"] = &domain.WorkTask{
+			ID:        "task-1",
+			ProjectID: "project-1",
+			Type:      domain.WorkTaskTypeBuild,
+			Status:    domain.WorkTaskStatusPending,
+			CreatedAt: time.Now(),
+		}
+
+		audit := newMockBuildAudit()
+		audit.entries["task-1"] = &domain.BuildAuditEntry{
+			TaskID:    "task-1",
+			ProjectID: "project-1",
+			Status:    domain.BuildStatusPending,
+		}
+
+		svc := NewWorkerService(registry, queue, nil).WithBuildAudit(audit)
+
+		task, err := svc.ClaimTask(ctx, "worker-1")
+		if err != nil {
+			t.Fatalf("ClaimTask() error = %v", err)
+		}
+		if task == nil {
+			t.Fatal("expected task to be returned")
+		}
+
+		// Verify audit was updated
+		entry := audit.entries["task-1"]
+		if entry.Status != domain.BuildStatusRunning {
+			t.Errorf("got audit status %q, want %q", entry.Status, domain.BuildStatusRunning)
+		}
+		if entry.WorkerID != "worker-1" {
+			t.Errorf("got audit worker_id %q, want %q", entry.WorkerID, "worker-1")
+		}
+	})
 }
 
 func TestWorkerService_CompleteTask(t *testing.T) {
diff --git a/internal/worker/mock_test.go b/internal/worker/mock_test.go
index 5e074c8..be1c35d 100644
--- a/internal/worker/mock_test.go
+++ b/internal/worker/mock_test.go
@@ -221,6 +221,18 @@ func (m *mockBuildAudit) Update(_ context.Context, taskID string, result *domain
 	return nil
 }
 
+func (m *mockBuildAudit) UpdateStatus(_ context.Context, taskID string, status domain.BuildStatus, workerID string) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	entry, ok := m.entries[taskID]
+	if !ok {
+		return domain.ErrBuildNotFound
+	}
+	entry.Status = status
+	entry.WorkerID = workerID
+	return nil
+}
+
 func (m *mockBuildAudit) Get(_ context.Context, taskID string) (*domain.BuildAuditEntry, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -308,7 +320,7 @@ func newTestDeps() *testDeps {
 		WithBuildAudit(audit)
 	workSvc := service.NewWorkService(queue, service.WorkServiceConfig{})
 
-	buildExec := NewBuildExecutor(agentRegistry, nil, nil)
+	buildExec := NewBuildExecutor(agentRegistry, nil, nil, nil)
 
 	return &testDeps{
 		queue:     queue,