Workflow Engine

An event-sourced automation engine. Workflows are versioned definitions; instance state is folded from an append-only event stream at read time, so nothing can drift. Runs are idempotent, transitions are config-validated, and outbound webhooks are delivered with an HMAC signature, exponential backoff, and dead-lettering. A single POST /api/tick advances the scheduler and the delivery queue.

Responsibilities

• Versioned workflow definitions with config-validated transitions
• Append-only instances; current step and status derived at read time
• Idempotent runs; event, schedule, webhook and manual triggers
• Interval scheduler with no catch-up backfill
• Outbound webhooks with backoff and dead-lettering

API surface

• GET/POST /api/workflows · POST /api/workflows/:key/run
• GET/POST /api/triggers
• GET /api/instances/:id · POST /api/instances/:id/advance
• GET/POST/DELETE /api/webhooks · GET /api/deliveries
• POST /api/events · POST /api/tick

CONSUMED BY Any module that needs automation, scheduling or event fan-out. A Platform Service never depends on a Business Module.