Changeset 0.27.3 (#170)

CHANGELOG.md

@@ -1,5 +1,62 @@
 # Changelog
 
+## [0.27.3] — 2026-03-10
+
+### Summary
+
+Task chaining — webhooks for external integration, AI-spawnable sub-tasks,
+and workflow-to-workflow completion triggers. Also fixes a bug where the
+`workflow_advance` tool didn't fire `on_complete` chains.
+
+### Added
+
+#### Webhook Delivery (`server/webhook/`)
+- **`webhook.Deliver(url, secret, payload)`** — POST with HMAC-SHA256 signing.
+  3 retries with exponential backoff (1s, 5s, 25s), 10s timeout per attempt.
+  `X-Switchboard-Signature` header for verification.
+- **`webhook.GenerateSecret()`** — 32-byte hex random secret, auto-generated
+  on task creation when `webhook_url` is set.
+- **`webhook.Payload`** struct: task_id, task_name, workflow_id, channel_id,
+  status, completed_at, output, stage_data, error.
+
+#### Task Webhooks
+- Task executor fires webhook on completion, failure, and budget breach.
+  Runs in a goroutine — non-blocking.
+- `webhook_secret` column on tasks table (migration 027).
+- Secret auto-generated in task handler `Create` when `webhook_url` is provided.
+
+#### Workflow Webhooks
+- `webhook_url` and `webhook_secret` columns on workflows table (migration 027).
+- Webhook delivered on workflow completion (both handler and tool paths).
+
+#### `task_create` Tool
+- AI-invocable tool that spawns sub-tasks from workflow/team contexts.
+- **Predicates:** available in workflow channels and team channels only.
+  Blocked in service channels (prevents recursive task spawning).
+- **Scope inheritance:** created tasks inherit parent channel's team scope.
+- **Depth limit:** service channel check prevents tasks creating tasks.
+- Parameters: name, prompt, schedule (cron or "once"), persona, model,
+  max_tokens, system_prompt. Validates cron before creation.
+
+#### Workflow `on_complete` Chaining Extraction
+- `TriggerWorkflowOnComplete()` extracted to `tools/workflow.go` as shared
+  function. Used by both HTTP handler and `workflow_advance` tool.
+- Handles both `on_complete` chain config and webhook delivery.
+
+### Fixed
+- **`workflow_advance` tool completion path** now triggers `on_complete`
+  chaining. Previously only the HTTP `Advance` endpoint fired chains —
+  AI-driven stage advancement silently skipped them.
+
+### Changed
+- `Workflow` model gains `WebhookURL`, `WebhookSecret` fields.
+- `WorkflowPatch` gains `WebhookURL` field.
+- `Task` model gains `WebhookSecret` field.
+- `workflow_instances.go` `triggerOnComplete` method replaced with
+  one-line delegation to shared `tools.TriggerWorkflowOnComplete()`.
+
+
+
 ## [0.27.2] — 2026-03-10
 
 ### Summary