Knock

API keys are per-environment (development, production). Secret keys for server-side API calls (workflow triggers, user management). Publishable keys for client-side SDK access (feed reads, preference updates). Secret keys are passed via Authorization: Bearer header. The secret/publishable key split ensures client-side code can't trigger workflows. Environment isolation prevents development triggers from reaching production channels. User tokens (signed JWTs) authenticate individual users for client-side operations. For agents, using secret keys for server-side workflow triggers and publishable keys for client-side feed access provides appropriate separation. No OAuth for third-party integrations. Token signing uses the secret key.

Knock provides notification infrastructure that separates notification logic from application code. For agents, the model is: define notification workflows (multi-channel sequences with conditions, delays, and batching), then trigger workflows via API when events occur. Knock handles channel routing (email, push, in-app, SMS, Slack, Discord, WhatsApp), user preference management (users choose which channels they receive notifications on), and delivery orchestration. The key agent value: notification logic (which channels, what delays, batch/digest rules) is managed in Knock's dashboard, not in application code. This means agents can trigger a workflow and Knock handles the complexity of multi-channel, preference-respecting delivery. In-app notification feed components provide pre-built UI. For agents building products with sophisticated notification requirements, Knock reduces notification engineering to a single API call per event.

REST API at api.knock.app/v1/. Workflow triggering: POST /workflows/{key}/trigger with recipients (user IDs), actor (who caused the event), and data (template variables). User management: PUT /users/{id} with properties and channel data (push tokens, email addresses). Preferences: GET/PUT /users/{id}/preferences for channel and workflow preferences. In-app feed: GET /users/{id}/feeds/{feed_id}/items returns notification items for the in-app feed. Bulk operations: trigger workflows for multiple recipients in a single request. Object-based triggers enable notifications about entities (comments on a document, updates to a project). Tenant support enables multi-tenant notification scoping. The API is clean and well-designed — workflow triggering is a single endpoint, and Knock handles the orchestration complexity.

API errors return JSON with code and message. Standard HTTP status codes. Workflow execution errors are visible in the Knock dashboard with per-step status (sent, skipped, failed) and channel provider error messages. Rate limits are generous for workflow triggers. Message delivery status is tracked per-channel: sent, delivered, read, seen, archived. Batch and digest workflows aggregate notifications over configurable time windows — reducing notification noise. The debug log in the dashboard shows every workflow execution with step-by-step detail. Channel provider failures (SendGrid down, APNs error) are reported with the provider's error message. For agents, the workflow execution visibility eliminates black-box notification debugging — every step's outcome is inspectable.

Documentation at docs.knock.app is well-organized with API reference, concept guides, SDK documentation, and integration guides. The workflow concept documentation explains triggers, steps, channels, conditions, batching, and digests. SDK documentation covers server (Node, Python, Ruby, Go, PHP, Java, Elixir, .NET) and client (JavaScript, React, iOS, Android) libraries. The in-app feed component documentation includes pre-built React components with customization guides. Channel provider integration guides cover SendGrid, Postmark, SES, APNs, FCM, Slack, and more. For agents, the workflow triggering guide and the concept documentation are essential starting points. The documentation effectively communicates the mental model shift from per-channel notification code to workflow-based orchestration.