Implement live webhook delivery dispatcher to drain webhook_outbox table

[Jagadeeshftw]

Description

The webhook_outbox table in PostgreSQL is populated when stream events occur, but the dispatcher that reads the outbox and performs actual HTTP delivery to consumer endpoints is not fully implemented in src/webhooks/service.ts. Rows accumulate in webhook_outbox indefinitely without being delivered. A polling dispatcher with at-least-once delivery semantics must be built and wired into the service startup lifecycle.

Requirements and context

• Implement a WebhookDispatcher class in src/webhooks/service.ts that polls webhook_outbox for unprocessed rows on a configurable WEBHOOK_POLL_INTERVAL_MS
• Use SELECT ... FOR UPDATE SKIP LOCKED to safely claim rows across concurrent workers without double-delivery
• Mark rows as processed by setting processed flag and delegating retries to src/webhooks/retry.ts on delivery failure
• Must be secure, tested, and documented
• Should be efficient and easy to review

Suggested execution

Fork the repo and create a branch

git checkout -b feature/webhook-outbox-dispatcher

Implement changes

• Update/Write: src/webhooks/service.ts — WebhookDispatcher with polling loop and FOR UPDATE SKIP LOCKED
• Update/Write: src/webhooks/retry.ts — integrate dispatcher failure path with retry scheduling
• Update/Write: src/shutdown.ts — gracefully drain in-flight deliveries on SIGTERM
• Write comprehensive tests: tests/webhooks/service.dispatcher.test.ts
• Add documentation: docs/webhooks.md — document outbox dispatcher lifecycle and delivery guarantees
• Include clear code comments and types
• Validate security assumptions

Test and commit

• Run tests: pnpm test (or pnpm test:coverage)
• Cover edge cases: empty outbox (no-op), successful delivery marks row processed, failed delivery enqueues retry, concurrent workers skip locked rows, graceful shutdown drains in-flight batch
• Include test output and security notes

Example commit message

feat: implement live webhook outbox dispatcher with at-least-once delivery

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours