Webhook Receiver Kit

Connectors are two-way streets: your agent calls APIs, but the world also calls you — Stripe payment events, GitHub push events, Slack interactivity callbacks. And webhook receivers are where integrations go to die quietly: unverified signatures (anyone can POST to your endpoint), duplicate deliveries processed twice (hello, double charges), no retry story (one 500 and the event is gone), no dead-lettering (failures vanish). This skill builds a webhook receiver that gets all of this right: signature verification per provider, idempotency keys, at-least-once processing with exactly-once effects, retries with backoff, dead-letter queue, and clean event routing to your agent's tools.

To produce a production webhook receiver for a given provider (or a generic multi-provider one): an HTTP endpoint that verifies authenticity, deduplicates deliveries, routes events to handlers, retries transient failures, parks poison events in a dead-letter queue, and logs everything with correlation IDs. The agent gets clean, trustworthy events; the human gets a dashboard-worthy audit trail.

• When building the inbound half of an agent connector (Stripe → agent, GitHub → agent, Slack events → agent).

• When an existing webhook endpoint is flaky, processes duplicates, or has no visibility into failures.

• When you need to receive webhooks from multiple providers through one endpoint with per-provider verification.

• When compliance or finance needs an audit trail of every inbound event and what the agent did with it.

• When the provider offers only polling (no webhooks) — use a scheduled poller instead; do not fake webhooks.

• When you need sub-second latency guarantees — webhooks are at-least-once with retries; design for seconds, not milliseconds.

• For outbound calls from your agent to APIs — that is mcp-server-scaffolder / rest-api-to-mcp-wrapper territory.

• When the event volume exceeds ~1000/sec sustained — this skill builds a single-service receiver; beyond that you need a streaming architecture (the skill will say so).