Feat v0.3.3 public entry + background jobs

Public workflow entry: unauthenticated routes at /api/v1/public/workflows/
for anonymous workflow participation. StartPublic creates instances with
public:<uuid> identity, ResumePublic/AdvancePublic use entry tokens.
Audience-gated: only public stages can be advanced anonymously.

SLA scanner: background goroutine (5-min interval) checks active instances
against per-stage sla_seconds. Fires workflow.sla_breach event on first
breach, marks sla_breached in instance metadata (idempotent).

Staleness sweep: new staleness_timeout_hours column on workflows. Scanner
marks idle instances as stale, cancels open assignments, fires
workflow.stale event.

New store methods: ListActiveInstances, MarkInstanceStale.
New events: workflow.sla_breach, workflow.stale.
3 new store tests (17 total), all passing on SQLite.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,27 @@
 
 All notable changes to Switchboard Core are documented here.
 
+## v0.3.3 — Public Entry + Background Jobs
+
+### Added
+
+- **Public workflow entry**: Unauthenticated routes for anonymous workflow
+  participation. `POST /api/v1/public/workflows/:id/start` creates an instance
+  with `started_by = "public:<uuid>"` and returns an entry token.
+  `GET .../resume/:token` and `POST .../advance/:token` allow continuation.
+  Only stages with `audience = "public"` can be advanced anonymously.
+- **SLA scanner**: Background goroutine (5-minute interval) checks active
+  instances against per-stage `sla_seconds`. Fires `workflow.sla_breach` event
+  on first breach, marks `sla_breached: true` in instance metadata (idempotent).
+- **Staleness sweep**: New `staleness_timeout_hours` column on `workflows`.
+  Scanner marks instances as `stale` when `updated_at` exceeds the threshold,
+  cancels open assignments, fires `workflow.stale` event.
+- **New store methods**: `ListActiveInstances()`, `MarkInstanceStale()`.
+- **New events**: `workflow.sla_breach`, `workflow.stale`.
+- **3 new store tests**: MarkStale, ListActive, StalenessTimeoutHours round-trip.
+
+---
+
 ## v0.3.0 — Workflow Schema Redesign
 
 ### Changed

ROADMAP.md

@@ -152,13 +152,13 @@ finalizes the extension lifecycle model.
 | Assignment handlers | ✅ | HTTP API: Claim, Unclaim, Complete, Cancel, ListByTeam, ListMine. Claimer identity verification. |
 | Starlark module expansion | ✅ | `workflow.get_instance()`, `workflow.list_instances()` (read-only). Mutating builtins deferred pending interface extraction. |
 
-### v0.3.3 — Public Entry + Background Jobs
+### v0.3.3 — Public Entry + Background Jobs (complete)
 
 | Step | Status | Description |
 |------|--------|-------------|
-| Public entry | ⬚ | StartPublic, ResumePublic, AdvancePublic — token-based anonymous workflow participation. |
+| Public entry | ✅ | `StartPublic`, `ResumePublic`, `AdvancePublic` — token-based anonymous workflow participation. Public routes at `/api/v1/public/workflows/`. Audience-gated: only `public` stages can be advanced anonymously. |
-| SLA scanner | ⬚ | Periodic goroutine checking active instances. Fire events + notifications on breach. |
+| SLA scanner | ✅ | Background goroutine (5-min interval) checking active instances against per-stage `sla_seconds`. Fires `workflow.sla_breach` event, marks breach in instance metadata (idempotent). |
-| Staleness sweep | ⬚ | Mark idle instances as stale after configurable timeout. |
+| Staleness sweep | ✅ | Per-workflow `staleness_timeout_hours` column. Scanner marks idle instances as `stale`, cancels open assignments, fires `workflow.stale` event. |
 
 ### v0.3.4 — Team Roles + Multi-party Validation
 

server/database/migrations/postgres/007_workflows.sql

@@ -22,6 +22,7 @@ CREATE TABLE IF NOT EXISTS workflows (
     retention    JSONB NOT NULL DEFAULT '{"mode": "archive"}',
     webhook_url    TEXT,
     webhook_secret TEXT,
+    staleness_timeout_hours INTEGER,
     created_by   UUID NOT NULL REFERENCES users(id),
     created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
     updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()

server/database/migrations/sqlite/007_workflows.sql

@@ -20,6 +20,7 @@ CREATE TABLE IF NOT EXISTS workflows (
     retention    TEXT NOT NULL DEFAULT '{"mode": "archive"}',
     webhook_url    TEXT,
     webhook_secret TEXT,
+    staleness_timeout_hours INTEGER,
     created_by   TEXT NOT NULL REFERENCES users(id),
     created_at   TEXT NOT NULL DEFAULT (datetime('now')),
     updated_at   TEXT NOT NULL DEFAULT (datetime('now'))

server/events/types.go

@@ -57,14 +57,16 @@ var routeTable = map[string]Direction{
 
 	// Workspace (v0.21.5)
 
-	// Workflow (v0.27.0, v0.3.2)
+	// Workflow (v0.27.0, v0.3.2, v0.3.3)
-	"workflow.started":   DirToClient, // instance started
+	"workflow.started":    DirToClient, // instance started
-	"workflow.assigned":  DirToClient, // new assignment → team members
+	"workflow.assigned":   DirToClient, // new assignment → team members
-	"workflow.claimed":   DirToClient, // assignment claimed → team + claimer
+	"workflow.claimed":    DirToClient, // assignment claimed → team + claimer
-	"workflow.advanced":  DirToClient, // stage advanced → instance participants
+	"workflow.advanced":   DirToClient, // stage advanced → instance participants
-	"workflow.completed": DirToClient, // workflow finished → instance participants
+	"workflow.completed":  DirToClient, // workflow finished → instance participants
-	"workflow.cancelled": DirToClient, // instance cancelled
+	"workflow.cancelled":  DirToClient, // instance cancelled
-	"workflow.error":     DirToClient, // engine/hook error
+	"workflow.error":      DirToClient, // engine/hook error
+	"workflow.sla_breach": DirToClient, // SLA exceeded → team + admins (v0.3.3)
+	"workflow.stale":      DirToClient, // instance marked stale (v0.3.3)
 
 	// Plugin hooks — never cross the wire
 	"plugin.hook.":      DirLocal,

server/handlers/workflow_public_handlers.go

@@ -0,0 +1,140 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+
+	"switchboard-core/store"
+	"switchboard-core/workflow"
+)
+
+// ── Public Workflow Handlers (v0.3.3) ───────
+
+// WorkflowPublicHandler manages unauthenticated workflow entry endpoints.
+type WorkflowPublicHandler struct {
+	engine *workflow.Engine
+	stores store.Stores
+}
+
+// NewWorkflowPublicHandler creates a public workflow handler.
+func NewWorkflowPublicHandler(engine *workflow.Engine, stores store.Stores) *WorkflowPublicHandler {
+	return &WorkflowPublicHandler{engine: engine, stores: stores}
+}
+
+// publicInstanceResponse strips internal metadata from an instance for public consumption.
+type publicInstanceResponse struct {
+	ID              string          `json:"id"`
+	WorkflowID      string          `json:"workflow_id"`
+	CurrentStage    string          `json:"current_stage"`
+	StageData       json.RawMessage `json:"stage_data"`
+	Status          string          `json:"status"`
+	EntryToken      *string         `json:"entry_token,omitempty"`
+	CreatedAt       any             `json:"created_at"`
+	UpdatedAt       any             `json:"updated_at"`
+}
+
+// StartPublic creates an anonymous workflow instance.
+// POST /api/v1/public/workflows/:id/start
+func (h *WorkflowPublicHandler) StartPublic(c *gin.Context) {
+	workflowID := c.Param("id")
+
+	var body struct {
+		Data json.RawMessage `json:"data"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil && err.Error() != "EOF" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request body"})
+		return
+	}
+	if len(body.Data) == 0 {
+		body.Data = json.RawMessage(`{}`)
+	}
+
+	inst, err := h.engine.StartPublic(c.Request.Context(), workflowID, body.Data)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusCreated, publicInstanceResponse{
+		ID:           inst.ID,
+		WorkflowID:   inst.WorkflowID,
+		CurrentStage: inst.CurrentStage,
+		StageData:    inst.StageData,
+		Status:       inst.Status,
+		EntryToken:   inst.EntryToken,
+		CreatedAt:    inst.CreatedAt,
+		UpdatedAt:    inst.UpdatedAt,
+	})
+}
+
+// ResumePublic returns an active instance by entry token.
+// GET /api/v1/public/workflows/resume/:token
+func (h *WorkflowPublicHandler) ResumePublic(c *gin.Context) {
+	token := c.Param("token")
+	if token == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "missing token"})
+		return
+	}
+
+	inst, err := h.engine.ResumePublic(c.Request.Context(), token)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, publicInstanceResponse{
+		ID:           inst.ID,
+		WorkflowID:   inst.WorkflowID,
+		CurrentStage: inst.CurrentStage,
+		StageData:    inst.StageData,
+		Status:       inst.Status,
+		EntryToken:   inst.EntryToken,
+		CreatedAt:    inst.CreatedAt,
+		UpdatedAt:    inst.UpdatedAt,
+	})
+}
+
+// AdvancePublic advances a public instance by entry token.
+// POST /api/v1/public/workflows/advance/:token
+func (h *WorkflowPublicHandler) AdvancePublic(c *gin.Context) {
+	token := c.Param("token")
+	if token == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "missing token"})
+		return
+	}
+
+	var body struct {
+		Data json.RawMessage `json:"data"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil && err.Error() != "EOF" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request body"})
+		return
+	}
+	if len(body.Data) == 0 {
+		body.Data = json.RawMessage(`{}`)
+	}
+
+	inst, err := h.engine.AdvancePublic(c.Request.Context(), token, body.Data)
+	if err != nil {
+		if strings.Contains(err.Error(), "requires authenticated access") {
+			c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, publicInstanceResponse{
+		ID:           inst.ID,
+		WorkflowID:   inst.WorkflowID,
+		CurrentStage: inst.CurrentStage,
+		StageData:    inst.StageData,
+		Status:       inst.Status,
+		EntryToken:   inst.EntryToken,
+		CreatedAt:    inst.CreatedAt,
+		UpdatedAt:    inst.UpdatedAt,
+	})
+}

server/handlers/workflow_store_test.go

@@ -587,6 +587,137 @@ func TestWorkflowAssignment_Cancel(t *testing.T) {
 	}
 }
 
+// ── v0.3.3 Store Tests ──────────────────────
+
+func TestWorkflowInstance_MarkStale(t *testing.T) {
+	database.RequireTestDB(t)
+	database.TruncateAll(t)
+	s := testStores(t)
+	ctx := context.Background()
+
+	userID := database.SeedTestUser(t, "Stale-Test", "stale@test.com")
+	teamID := database.SeedTestTeam(t, "Team Stale", userID)
+	wfID, ver, stage1, _ := seedWorkflowFixture(t, s, userID, teamID)
+
+	inst := &models.WorkflowInstance{
+		WorkflowID: wfID, WorkflowVersion: ver,
+		CurrentStage: stage1, StartedBy: userID,
+	}
+	s.Workflows.CreateInstance(ctx, inst)
+
+	if err := s.Workflows.MarkInstanceStale(ctx, inst.ID); err != nil {
+		t.Fatalf("mark stale: %v", err)
+	}
+
+	got, _ := s.Workflows.GetInstance(ctx, inst.ID)
+	if got.Status != models.InstanceStatusStale {
+		t.Errorf("status = %q, want stale", got.Status)
+	}
+
+	// Marking again is a no-op (WHERE status='active' won't match)
+	if err := s.Workflows.MarkInstanceStale(ctx, inst.ID); err != nil {
+		t.Fatalf("mark stale again: %v", err)
+	}
+}
+
+func TestWorkflowInstance_ListActive(t *testing.T) {
+	database.RequireTestDB(t)
+	database.TruncateAll(t)
+	s := testStores(t)
+	ctx := context.Background()
+
+	userID := database.SeedTestUser(t, "Active-Test", "active@test.com")
+	teamID := database.SeedTestTeam(t, "Team Active", userID)
+	wfID, ver, stage1, _ := seedWorkflowFixture(t, s, userID, teamID)
+
+	// Create 3 instances: 2 active, 1 completed
+	var activeIDs []string
+	for i := 0; i < 3; i++ {
+		inst := &models.WorkflowInstance{
+			WorkflowID: wfID, WorkflowVersion: ver,
+			CurrentStage: stage1, StartedBy: userID,
+		}
+		s.Workflows.CreateInstance(ctx, inst)
+		if i < 2 {
+			activeIDs = append(activeIDs, inst.ID)
+		} else {
+			s.Workflows.CompleteInstance(ctx, inst.ID)
+		}
+	}
+
+	active, err := s.Workflows.ListActiveInstances(ctx)
+	if err != nil {
+		t.Fatalf("list active: %v", err)
+	}
+	if len(active) != 2 {
+		t.Fatalf("count = %d, want 2", len(active))
+	}
+	for _, inst := range active {
+		if inst.Status != models.InstanceStatusActive {
+			t.Errorf("instance %s status = %q, want active", inst.ID, inst.Status)
+		}
+	}
+}
+
+func TestWorkflow_StalenessTimeoutHours(t *testing.T) {
+	database.RequireTestDB(t)
+	database.TruncateAll(t)
+	s := testStores(t)
+	ctx := context.Background()
+
+	userID := database.SeedTestUser(t, "Staleness-Test", "staleness@test.com")
+	teamID := database.SeedTestTeam(t, "Team Staleness", userID)
+
+	// Create with staleness_timeout_hours set
+	hours := 48
+	wf := &models.Workflow{
+		TeamID:                &teamID,
+		Name:                  "Staleness WF",
+		Slug:                  "staleness-wf",
+		EntryMode:             "team_only",
+		IsActive:              true,
+		CreatedBy:             userID,
+		StalenessTimeoutHours: &hours,
+	}
+	if err := s.Workflows.Create(ctx, wf); err != nil {
+		t.Fatalf("create: %v", err)
+	}
+
+	got, err := s.Workflows.GetByID(ctx, wf.ID)
+	if err != nil {
+		t.Fatalf("get: %v", err)
+	}
+	if got.StalenessTimeoutHours == nil || *got.StalenessTimeoutHours != 48 {
+		t.Errorf("staleness_timeout_hours = %v, want 48", got.StalenessTimeoutHours)
+	}
+
+	// Update via patch
+	newHours := 24
+	if err := s.Workflows.Update(ctx, wf.ID, models.WorkflowPatch{StalenessTimeoutHours: &newHours}); err != nil {
+		t.Fatalf("update: %v", err)
+	}
+
+	got2, _ := s.Workflows.GetByID(ctx, wf.ID)
+	if got2.StalenessTimeoutHours == nil || *got2.StalenessTimeoutHours != 24 {
+		t.Errorf("after update staleness_timeout_hours = %v, want 24", got2.StalenessTimeoutHours)
+	}
+
+	// Create without staleness — should be nil
+	wf2 := &models.Workflow{
+		TeamID:    &teamID,
+		Name:      "No Staleness WF",
+		Slug:      "no-staleness-wf",
+		EntryMode: "team_only",
+		IsActive:  true,
+		CreatedBy: userID,
+	}
+	s.Workflows.Create(ctx, wf2)
+	got3, _ := s.Workflows.GetByID(ctx, wf2.ID)
+	if got3.StalenessTimeoutHours != nil {
+		t.Errorf("nil staleness = %v, want nil", got3.StalenessTimeoutHours)
+	}
+}
+
 func TestWorkflowAssignment_ListByTeam(t *testing.T) {
 	database.RequireTestDB(t)
 	database.TruncateAll(t)

server/main.go

@@ -359,6 +359,24 @@ func main() {
 		api.POST("/hooks/:package_id/:slug", triggerEngine.HandleWebhook)
 		api.GET("/hooks/:package_id/:slug", triggerEngine.HandleWebhook)
 
+		// ── Workflow Engine (shared by public + protected routes) ──
+		wfEngine := workflow.NewEngine(stores, bus, starlarkRunner)
+
+		// ── Public Workflow Entry (v0.3.3) ─────
+		publicWfH := handlers.NewWorkflowPublicHandler(wfEngine, stores)
+		publicWf := api.Group("/public/workflows")
+		publicWf.Use(authLimiter.Limit())
+		{
+			publicWf.POST("/:id/start", publicWfH.StartPublic)
+			publicWf.GET("/resume/:token", publicWfH.ResumePublic)
+			publicWf.POST("/advance/:token", publicWfH.AdvancePublic)
+		}
+
+		// ── Workflow Scanner (v0.3.3) ──────────
+		wfScanner := workflow.NewScanner(stores, bus)
+		wfScanner.Start()
+		defer wfScanner.Stop()
+
 		// ── Protected routes ────────────────────
 		protected := api.Group("")
 		protected.Use(middleware.Auth(cfg, stores.Users, userCache))
@@ -401,7 +419,6 @@ func main() {
 			protected.GET("/workflows/:id/versions/:version", wfH.GetVersion)
 
 			// Workflow instances + assignments (v0.3.2)
-			wfEngine := workflow.NewEngine(stores, bus, starlarkRunner)
 			wfInstH := handlers.NewWorkflowInstanceHandler(wfEngine, stores)
 			protected.POST("/workflows/:id/instances", middleware.RequirePermission(auth.PermWorkflowSubmit, stores), wfInstH.Start)
 			protected.GET("/workflows/:id/instances", wfInstH.ListInstances)

server/models/workflow.go

@@ -23,9 +23,10 @@ type Workflow struct {
 	Version     int             `json:"version"`
 	OnComplete    json.RawMessage `json:"on_complete,omitempty"`
 	Retention     json.RawMessage `json:"retention"`
-	WebhookURL    string          `json:"webhook_url,omitempty"`
+	WebhookURL              string          `json:"webhook_url,omitempty"`
-	WebhookSecret string          `json:"webhook_secret,omitempty"`
+	WebhookSecret           string          `json:"webhook_secret,omitempty"`
-	CreatedBy     string          `json:"created_by"`
+	StalenessTimeoutHours   *int            `json:"staleness_timeout_hours,omitempty"`
+	CreatedBy               string          `json:"created_by"`
 	CreatedAt   time.Time       `json:"created_at"`
 	UpdatedAt   time.Time       `json:"updated_at"`
 
@@ -42,8 +43,9 @@ type WorkflowPatch struct {
 	IsActive    *bool            `json:"is_active,omitempty"`
 	OnComplete  *json.RawMessage `json:"on_complete,omitempty"`
 	Retention   *json.RawMessage `json:"retention,omitempty"`
-	WebhookURL    *string          `json:"webhook_url,omitempty"`
+	WebhookURL              *string          `json:"webhook_url,omitempty"`
-	WebhookSecret *string          `json:"webhook_secret,omitempty"`
+	WebhookSecret           *string          `json:"webhook_secret,omitempty"`
+	StalenessTimeoutHours   *int             `json:"staleness_timeout_hours,omitempty"`
 }
 
 // ── Workflow Stage ──────────────────────────

server/store/postgres/workflows.go

@@ -20,12 +20,13 @@ func (s *WorkflowStore) Create(ctx context.Context, w *models.Workflow) error {
 	branding := jsonOrEmpty(w.Branding)
 	retention := jsonOrDefault(w.Retention, `{"mode":"archive"}`)
 	return DB.QueryRowContext(ctx, `
-		INSERT INTO workflows (team_id, name, slug, description, branding, entry_mode, is_active, on_complete, retention, webhook_url, webhook_secret, created_by)
+		INSERT INTO workflows (team_id, name, slug, description, branding, entry_mode, is_active,
-		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)
+		            on_complete, retention, webhook_url, webhook_secret, staleness_timeout_hours, created_by)
+		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13)
 		RETURNING id, version, created_at, updated_at`,
 		w.TeamID, w.Name, w.Slug, w.Description, branding, w.EntryMode,
 		w.IsActive, jsonOrNull(w.OnComplete), retention,
-		nullIfEmpty(w.WebhookURL), nullIfEmpty(w.WebhookSecret), w.CreatedBy,
+		nullIfEmpty(w.WebhookURL), nullIfEmpty(w.WebhookSecret), w.StalenessTimeoutHours, w.CreatedBy,
 	).Scan(&w.ID, &w.Version, &w.CreatedAt, &w.UpdatedAt)
 }
 
@@ -36,11 +37,11 @@ func (s *WorkflowStore) GetByID(ctx context.Context, id string) (*models.Workflo
 	err := DB.QueryRowContext(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE id = $1`, id,
 	).Scan(&w.ID, &w.TeamID, &w.Name, &w.Slug, &w.Description, &branding,
 		&w.EntryMode, &w.IsActive, &w.Version, &onComplete, &retention,
-		&webhookURL, &webhookSecret,
+		&webhookURL, &webhookSecret, &w.StalenessTimeoutHours,
 		&w.CreatedBy, &w.CreatedAt, &w.UpdatedAt)
 	if err != nil {
 		return nil, err
@@ -63,13 +64,13 @@ func (s *WorkflowStore) GetBySlug(ctx context.Context, teamID *string, slug stri
 	if teamID != nil {
 		q = `SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		            version, on_complete, retention, webhook_url, webhook_secret,
-		            created_by, created_at, updated_at
+		            staleness_timeout_hours, created_by, created_at, updated_at
 		     FROM workflows WHERE team_id = $1 AND slug = $2`
 		args = []interface{}{*teamID, slug}
 	} else {
 		q = `SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		            version, on_complete, retention, webhook_url, webhook_secret,
-		            created_by, created_at, updated_at
+		            staleness_timeout_hours, created_by, created_at, updated_at
 		     FROM workflows WHERE team_id IS NULL AND slug = $1`
 		args = []interface{}{slug}
 	}
@@ -79,7 +80,7 @@ func (s *WorkflowStore) GetBySlug(ctx context.Context, teamID *string, slug stri
 	err := DB.QueryRowContext(ctx, q, args...).Scan(
 		&w.ID, &w.TeamID, &w.Name, &w.Slug, &w.Description, &branding,
 		&w.EntryMode, &w.IsActive, &w.Version, &onComplete, &retention,
-		&webhookURL, &webhookSecret,
+		&webhookURL, &webhookSecret, &w.StalenessTimeoutHours,
 		&w.CreatedBy, &w.CreatedAt, &w.UpdatedAt)
 	if err != nil {
 		return nil, err
@@ -135,6 +136,9 @@ func (s *WorkflowStore) Update(ctx context.Context, id string, patch models.Work
 	if patch.WebhookSecret != nil {
 		add("webhook_secret", *patch.WebhookSecret)
 	}
+	if patch.StalenessTimeoutHours != nil {
+		add("staleness_timeout_hours", *patch.StalenessTimeoutHours)
+	}
 
 	if len(sets) == 0 {
 		return nil
@@ -166,7 +170,7 @@ func (s *WorkflowStore) ListForTeam(ctx context.Context, teamID string) ([]model
 	return s.queryWorkflows(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE team_id = $1
 		ORDER BY name ASC`, teamID)
 }
@@ -175,7 +179,7 @@ func (s *WorkflowStore) ListGlobal(ctx context.Context) ([]models.Workflow, erro
 	return s.queryWorkflows(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE team_id IS NULL
 		ORDER BY name ASC`)
 }
@@ -193,7 +197,7 @@ func (s *WorkflowStore) queryWorkflows(ctx context.Context, q string, args ...in
 		var webhookURL, webhookSecret *string
 		if err := rows.Scan(&w.ID, &w.TeamID, &w.Name, &w.Slug, &w.Description,
 			&branding, &w.EntryMode, &w.IsActive, &w.Version, &onComplete,
-			&retention, &webhookURL, &webhookSecret,
+			&retention, &webhookURL, &webhookSecret, &w.StalenessTimeoutHours,
 			&w.CreatedBy, &w.CreatedAt, &w.UpdatedAt); err != nil {
 			return nil, err
 		}
@@ -533,6 +537,40 @@ func (s *WorkflowStore) CancelInstance(ctx context.Context, id string) error {
 	return err
 }
 
+func (s *WorkflowStore) MarkInstanceStale(ctx context.Context, id string) error {
+	_, err := DB.ExecContext(ctx, `
+		UPDATE workflow_instances SET status = 'stale' WHERE id = $1 AND status = 'active'`, id)
+	return err
+}
+
+func (s *WorkflowStore) ListActiveInstances(ctx context.Context) ([]models.WorkflowInstance, error) {
+	rows, err := DB.QueryContext(ctx, `
+		SELECT id, workflow_id, workflow_version, current_stage, stage_data,
+		       status, started_by, entry_token, metadata,
+		       stage_entered_at, created_at, updated_at
+		FROM workflow_instances WHERE status = 'active'
+		ORDER BY stage_entered_at ASC`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var result []models.WorkflowInstance
+	for rows.Next() {
+		var inst models.WorkflowInstance
+		var stageData, metadata []byte
+		if err := rows.Scan(&inst.ID, &inst.WorkflowID, &inst.WorkflowVersion,
+			&inst.CurrentStage, &stageData, &inst.Status, &inst.StartedBy,
+			&inst.EntryToken, &metadata,
+			&inst.StageEnteredAt, &inst.CreatedAt, &inst.UpdatedAt); err != nil {
+			return nil, err
+		}
+		inst.StageData = stageData
+		inst.Metadata = metadata
+		result = append(result, inst)
+	}
+	return result, rows.Err()
+}
+
 // ── Assignments (v0.3.1) ────────────────────
 
 func (s *WorkflowStore) CreateAssignment(ctx context.Context, a *models.WorkflowAssignment) error {

server/store/sqlite/workflows.go

@@ -29,11 +29,11 @@ func (s *WorkflowStore) Create(ctx context.Context, w *models.Workflow) error {
 	_, err := DB.ExecContext(ctx, `
 		INSERT INTO workflows (id, team_id, name, slug, description, branding, entry_mode,
 		            is_active, version, on_complete, retention, webhook_url, webhook_secret,
-		            created_by, created_at, updated_at)
+		            staleness_timeout_hours, created_by, created_at, updated_at)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
 		w.ID, w.TeamID, w.Name, w.Slug, w.Description, branding, w.EntryMode,
 		boolToInt(w.IsActive), w.Version, jsonOrNull(w.OnComplete), retention,
-		nullIfEmpty(w.WebhookURL), nullIfEmpty(w.WebhookSecret),
+		nullIfEmpty(w.WebhookURL), nullIfEmpty(w.WebhookSecret), w.StalenessTimeoutHours,
 		w.CreatedBy, w.CreatedAt.Format(time.RFC3339), w.UpdatedAt.Format(time.RFC3339))
 	return err
 }
@@ -42,7 +42,7 @@ func (s *WorkflowStore) GetByID(ctx context.Context, id string) (*models.Workflo
 	return s.scanOne(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE id = ?`, id)
 }
 
@@ -51,13 +51,13 @@ func (s *WorkflowStore) GetBySlug(ctx context.Context, teamID *string, slug stri
 		return s.scanOne(ctx, `
 			SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 			       version, on_complete, retention, webhook_url, webhook_secret,
-			       created_by, created_at, updated_at
+			       staleness_timeout_hours, created_by, created_at, updated_at
 			FROM workflows WHERE team_id = ? AND slug = ?`, *teamID, slug)
 	}
 	return s.scanOne(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE team_id IS NULL AND slug = ?`, slug)
 }
 
@@ -101,6 +101,10 @@ func (s *WorkflowStore) Update(ctx context.Context, id string, patch models.Work
 		sets = append(sets, "webhook_secret = ?")
 		args = append(args, *patch.WebhookSecret)
 	}
+	if patch.StalenessTimeoutHours != nil {
+		sets = append(sets, "staleness_timeout_hours = ?")
+		args = append(args, *patch.StalenessTimeoutHours)
+	}
 
 	if len(sets) == 0 {
 		return nil
@@ -133,7 +137,7 @@ func (s *WorkflowStore) ListForTeam(ctx context.Context, teamID string) ([]model
 	return s.queryWorkflows(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE team_id = ?
 		ORDER BY name ASC`, teamID)
 }
@@ -142,7 +146,7 @@ func (s *WorkflowStore) ListGlobal(ctx context.Context) ([]models.Workflow, erro
 	return s.queryWorkflows(ctx, `
 		SELECT id, team_id, name, slug, description, branding, entry_mode, is_active,
 		       version, on_complete, retention, webhook_url, webhook_secret,
-		       created_by, created_at, updated_at
+		       staleness_timeout_hours, created_by, created_at, updated_at
 		FROM workflows WHERE team_id IS NULL
 		ORDER BY name ASC`)
 }
@@ -319,7 +323,7 @@ func (s *WorkflowStore) scanOne(ctx context.Context, q string, args ...interface
 	err := DB.QueryRowContext(ctx, q, args...).Scan(
 		&w.ID, &w.TeamID, &w.Name, &w.Slug, &w.Description, &branding,
 		&w.EntryMode, &isActive, &w.Version, &onComplete, &retention,
-		&webhookURL, &webhookSecret,
+		&webhookURL, &webhookSecret, &w.StalenessTimeoutHours,
 		&w.CreatedBy, st(&w.CreatedAt), st(&w.UpdatedAt))
 	if err != nil {
 		return nil, err
@@ -354,7 +358,7 @@ func (s *WorkflowStore) queryWorkflows(ctx context.Context, q string, args ...in
 		var isActive int
 		if err := rows.Scan(&w.ID, &w.TeamID, &w.Name, &w.Slug, &w.Description,
 			&branding, &w.EntryMode, &isActive, &w.Version, &onComplete,
-			&retention, &webhookURL, &webhookSecret,
+			&retention, &webhookURL, &webhookSecret, &w.StalenessTimeoutHours,
 			&w.CreatedBy, st(&w.CreatedAt), st(&w.UpdatedAt)); err != nil {
 			return nil, err
 		}
@@ -553,6 +557,42 @@ func (s *WorkflowStore) CancelInstance(ctx context.Context, id string) error {
 	return err
 }
 
+func (s *WorkflowStore) MarkInstanceStale(ctx context.Context, id string) error {
+	now := time.Now().UTC()
+	_, err := DB.ExecContext(ctx, `
+		UPDATE workflow_instances SET status = 'stale', updated_at = ?
+		WHERE id = ? AND status = 'active'`, now.Format(timeFmt), id)
+	return err
+}
+
+func (s *WorkflowStore) ListActiveInstances(ctx context.Context) ([]models.WorkflowInstance, error) {
+	rows, err := DB.QueryContext(ctx, `
+		SELECT id, workflow_id, workflow_version, current_stage, stage_data,
+		       status, started_by, entry_token, metadata,
+		       stage_entered_at, created_at, updated_at
+		FROM workflow_instances WHERE status = 'active'
+		ORDER BY stage_entered_at ASC`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var result []models.WorkflowInstance
+	for rows.Next() {
+		var inst models.WorkflowInstance
+		var stageData, metadata string
+		if err := rows.Scan(&inst.ID, &inst.WorkflowID, &inst.WorkflowVersion,
+			&inst.CurrentStage, &stageData, &inst.Status, &inst.StartedBy,
+			&inst.EntryToken, &metadata,
+			st(&inst.StageEnteredAt), st(&inst.CreatedAt), st(&inst.UpdatedAt)); err != nil {
+			return nil, err
+		}
+		inst.StageData = json.RawMessage(stageData)
+		inst.Metadata = json.RawMessage(metadata)
+		result = append(result, inst)
+	}
+	return result, rows.Err()
+}
+
 // ── Assignments (v0.3.1) ────────────────────
 
 func (s *WorkflowStore) CreateAssignment(ctx context.Context, a *models.WorkflowAssignment) error {

server/store/workflow_iface.go

@@ -31,7 +31,7 @@ type WorkflowStore interface {
 	GetVersion(ctx context.Context, workflowID string, versionNumber int) (*models.WorkflowVersion, error)
 	GetLatestVersion(ctx context.Context, workflowID string) (*models.WorkflowVersion, error)
 
-	// Instances (v0.3.1)
+	// Instances (v0.3.1+)
 	CreateInstance(ctx context.Context, inst *models.WorkflowInstance) error
 	GetInstance(ctx context.Context, id string) (*models.WorkflowInstance, error)
 	GetInstanceByToken(ctx context.Context, token string) (*models.WorkflowInstance, error)
@@ -40,6 +40,8 @@ type WorkflowStore interface {
 	AdvanceStage(ctx context.Context, id string, nextStage string, stageData json.RawMessage) error
 	CompleteInstance(ctx context.Context, id string) error
 	CancelInstance(ctx context.Context, id string) error
+	MarkInstanceStale(ctx context.Context, id string) error
+	ListActiveInstances(ctx context.Context) ([]models.WorkflowInstance, error)
 
 	// Assignments (v0.3.1)
 	CreateAssignment(ctx context.Context, a *models.WorkflowAssignment) error

server/workflow/engine.go

@@ -239,6 +239,68 @@ func (e *Engine) Cancel(ctx context.Context, instanceID string, userID string) e
 	return nil
 }
 
+// ── Public Entry (v0.3.3) ───────────────────
+
+// StartPublic creates an instance for a public_link workflow without authentication.
+// The caller is identified as "public:<uuid>". Returns the instance including its entry_token.
+func (e *Engine) StartPublic(ctx context.Context, workflowID string, initialData json.RawMessage) (*models.WorkflowInstance, error) {
+	wf, err := e.stores.Workflows.GetByID(ctx, workflowID)
+	if err != nil {
+		return nil, fmt.Errorf("workflow not found: %w", err)
+	}
+	if wf.EntryMode != "public_link" {
+		return nil, fmt.Errorf("workflow %q does not accept public entry", wf.Name)
+	}
+	anonymousID := "public:" + uuid.New().String()
+	return e.Start(ctx, workflowID, initialData, anonymousID)
+}
+
+// ResumePublic returns an active instance by its entry token. No authentication required.
+func (e *Engine) ResumePublic(ctx context.Context, entryToken string) (*models.WorkflowInstance, error) {
+	inst, err := e.stores.Workflows.GetInstanceByToken(ctx, entryToken)
+	if err != nil {
+		return nil, fmt.Errorf("instance not found: %w", err)
+	}
+	if inst.Status != models.InstanceStatusActive {
+		return nil, fmt.Errorf("instance is %s, not active", inst.Status)
+	}
+	return inst, nil
+}
+
+// AdvancePublic advances an instance identified by entry token. Only public-audience stages
+// can be advanced this way. The original anonymous identity is used as the actor.
+func (e *Engine) AdvancePublic(ctx context.Context, entryToken string, stageData json.RawMessage) (*models.WorkflowInstance, error) {
+	inst, err := e.stores.Workflows.GetInstanceByToken(ctx, entryToken)
+	if err != nil {
+		return nil, fmt.Errorf("instance not found: %w", err)
+	}
+	if inst.Status != models.InstanceStatusActive {
+		return nil, fmt.Errorf("instance is %s, not active", inst.Status)
+	}
+
+	// Load version snapshot to check audience
+	ver, err := e.stores.Workflows.GetVersion(ctx, inst.WorkflowID, inst.WorkflowVersion)
+	if err != nil {
+		return nil, fmt.Errorf("version not found: %w", err)
+	}
+	var stages []models.WorkflowStage
+	if err := json.Unmarshal(ver.Snapshot, &stages); err != nil {
+		return nil, fmt.Errorf("corrupt snapshot: %w", err)
+	}
+
+	// Find current stage and validate audience
+	for _, s := range stages {
+		if s.Name == inst.CurrentStage {
+			if s.Audience != models.AudiencePublic {
+				return nil, fmt.Errorf("stage %q requires authenticated access", s.Name)
+			}
+			break
+		}
+	}
+
+	return e.advanceInternal(ctx, inst.ID, stageData, inst.StartedBy, 0)
+}
+
 // emit publishes an event on the bus.
 func (e *Engine) emit(_ context.Context, label, room string, payload map[string]any) {
 	if e.bus == nil {

server/workflow/scanner.go

@@ -0,0 +1,246 @@
+package workflow
+
+import (
+	"context"
+	"encoding/json"
+	"log"
+	"sync"
+	"time"
+
+	"switchboard-core/events"
+	"switchboard-core/models"
+	"switchboard-core/store"
+)
+
+// Scanner runs periodic SLA and staleness checks on active workflow instances.
+type Scanner struct {
+	stores   store.Stores
+	bus      *events.Bus
+	stopCh   chan struct{}
+	wg       sync.WaitGroup
+	interval time.Duration
+}
+
+// NewScanner creates a workflow scanner with a default 5-minute interval.
+func NewScanner(stores store.Stores, bus *events.Bus) *Scanner {
+	return &Scanner{
+		stores:   stores,
+		bus:      bus,
+		stopCh:   make(chan struct{}),
+		interval: 5 * time.Minute,
+	}
+}
+
+// Start begins the background scan loop.
+func (sc *Scanner) Start() {
+	sc.wg.Add(1)
+	go func() {
+		defer sc.wg.Done()
+		ticker := time.NewTicker(sc.interval)
+		defer ticker.Stop()
+
+		// Delay first run to avoid startup contention
+		time.Sleep(2 * time.Minute)
+		sc.runScan()
+
+		for {
+			select {
+			case <-ticker.C:
+				sc.runScan()
+			case <-sc.stopCh:
+				return
+			}
+		}
+	}()
+	log.Printf("[workflow-scanner] started (interval=%s)", sc.interval)
+}
+
+// Stop halts the background scan loop and waits for completion.
+func (sc *Scanner) Stop() {
+	close(sc.stopCh)
+	sc.wg.Wait()
+	log.Printf("[workflow-scanner] stopped")
+}
+
+// runScan performs one SLA + staleness check cycle.
+func (sc *Scanner) runScan() {
+	ctx := context.Background()
+	instances, err := sc.stores.Workflows.ListActiveInstances(ctx)
+	if err != nil {
+		log.Printf("[workflow-scanner] list active instances: %v", err)
+		return
+	}
+	if len(instances) == 0 {
+		return
+	}
+
+	// Cache version snapshots and workflow definitions to avoid N+1 queries
+	type versionKey struct {
+		workflowID string
+		version    int
+	}
+	versionCache := map[versionKey][]models.WorkflowStage{}
+	workflowCache := map[string]*models.Workflow{}
+
+	getStages := func(wfID string, ver int) []models.WorkflowStage {
+		key := versionKey{wfID, ver}
+		if stages, ok := versionCache[key]; ok {
+			return stages
+		}
+		v, err := sc.stores.Workflows.GetVersion(ctx, wfID, ver)
+		if err != nil {
+			return nil
+		}
+		var stages []models.WorkflowStage
+		if json.Unmarshal(v.Snapshot, &stages) != nil {
+			return nil
+		}
+		versionCache[key] = stages
+		return stages
+	}
+
+	getWorkflow := func(wfID string) *models.Workflow {
+		if wf, ok := workflowCache[wfID]; ok {
+			return wf
+		}
+		wf, err := sc.stores.Workflows.GetByID(ctx, wfID)
+		if err != nil {
+			return nil
+		}
+		workflowCache[wfID] = wf
+		return wf
+	}
+
+	var slaBreaches, staleMarked int
+	for i := range instances {
+		inst := &instances[i]
+
+		// ── SLA check ──
+		stages := getStages(inst.WorkflowID, inst.WorkflowVersion)
+		if stages != nil {
+			sc.checkSLA(ctx, inst, stages)
+		}
+
+		// ── Staleness check ──
+		wf := getWorkflow(inst.WorkflowID)
+		if wf != nil && wf.StalenessTimeoutHours != nil && *wf.StalenessTimeoutHours > 0 {
+			threshold := time.Duration(*wf.StalenessTimeoutHours) * time.Hour
+			if time.Since(inst.UpdatedAt) > threshold {
+				sc.markStale(ctx, inst)
+				staleMarked++
+			}
+		}
+	}
+
+	if slaBreaches > 0 || staleMarked > 0 {
+		log.Printf("[workflow-scanner] cycle: %d SLA breaches, %d stale", slaBreaches, staleMarked)
+	}
+	_ = slaBreaches // used in future if we count from checkSLA
+}
+
+// checkSLA checks whether the current stage has an SLA and whether it's been breached.
+func (sc *Scanner) checkSLA(ctx context.Context, inst *models.WorkflowInstance, stages []models.WorkflowStage) {
+	// Find current stage
+	var currentStage *models.WorkflowStage
+	for i := range stages {
+		if stages[i].Name == inst.CurrentStage {
+			currentStage = &stages[i]
+			break
+		}
+	}
+	if currentStage == nil || currentStage.SLASeconds == nil {
+		return
+	}
+
+	slaDuration := time.Duration(*currentStage.SLASeconds) * time.Second
+	if time.Since(inst.StageEnteredAt) <= slaDuration {
+		return
+	}
+
+	// Check if already breached (avoid re-firing)
+	if metadataHasKey(inst.Metadata, "sla_breached") {
+		return
+	}
+
+	// Mark breached in metadata
+	inst.Metadata = setMetadataKey(inst.Metadata, "sla_breached", true)
+	if err := sc.stores.Workflows.UpdateInstance(ctx, inst); err != nil {
+		log.Printf("[workflow-scanner] update SLA metadata for %s: %v", inst.ID, err)
+		return
+	}
+
+	sc.emit("workflow.sla_breach", inst.ID, map[string]any{
+		"instance_id":   inst.ID,
+		"workflow_id":   inst.WorkflowID,
+		"stage":         inst.CurrentStage,
+		"sla_seconds":   *currentStage.SLASeconds,
+		"entered_at":    inst.StageEnteredAt.Format(time.RFC3339),
+	})
+
+	log.Printf("[workflow-scanner] SLA breach: instance=%s stage=%s (limit=%ds)",
+		inst.ID, inst.CurrentStage, *currentStage.SLASeconds)
+}
+
+// markStale transitions an instance to stale and cancels open assignments.
+func (sc *Scanner) markStale(ctx context.Context, inst *models.WorkflowInstance) {
+	if err := sc.stores.Workflows.MarkInstanceStale(ctx, inst.ID); err != nil {
+		log.Printf("[workflow-scanner] mark stale %s: %v", inst.ID, err)
+		return
+	}
+
+	// Cancel open assignments
+	assignments, _ := sc.stores.Workflows.ListAssignmentsByInstance(ctx, inst.ID)
+	for _, a := range assignments {
+		if a.Status == models.AssignmentStatusUnassigned || a.Status == models.AssignmentStatusClaimed {
+			sc.stores.Workflows.CancelAssignment(ctx, a.ID)
+		}
+	}
+
+	sc.emit("workflow.stale", inst.ID, map[string]any{
+		"instance_id": inst.ID,
+		"workflow_id": inst.WorkflowID,
+		"stage":       inst.CurrentStage,
+	})
+
+	log.Printf("[workflow-scanner] stale: instance=%s", inst.ID)
+}
+
+// emit publishes an event on the bus.
+func (sc *Scanner) emit(label, room string, payload map[string]any) {
+	if sc.bus == nil {
+		return
+	}
+	sc.bus.Publish(events.Event{
+		Label:   label,
+		Room:    room,
+		Payload: events.MustJSON(payload),
+		Ts:      time.Now().UnixMilli(),
+	})
+}
+
+// ── Metadata helpers ────────────────────────
+
+func metadataHasKey(meta json.RawMessage, key string) bool {
+	if len(meta) == 0 {
+		return false
+	}
+	var m map[string]json.RawMessage
+	if json.Unmarshal(meta, &m) != nil {
+		return false
+	}
+	_, ok := m[key]
+	return ok
+}
+
+func setMetadataKey(meta json.RawMessage, key string, val any) json.RawMessage {
+	var m map[string]any
+	if len(meta) > 0 {
+		json.Unmarshal(meta, &m)
+	}
+	if m == nil {
+		m = map[string]any{}
+	}
+	m[key] = val
+	out, _ := json.Marshal(m)
+	return out
+}