What problem does it solve? Cloudflare Queues deliver messages at-least-once, so any non-deterministic id or clock read in an agent core causes duplicate invoices, double-sent emails, and broken dedupe on redelivery. This Skill encodes the exact recipe that makes redelivery safe: deterministic ids derived from the trigger event, layered dedupe defenses, and a three-adapter port for every external vendor seam. ## Core Features & Use Cases - Deterministic id recipe: A domain-separated SHA-256 shaped into a v4-variant UUID for event ids, plus prefix_<16hex> shapes for shipment, party, and invoice ids, so a redelivered trigger reproduces identical primary keys. - Three-adapter port pattern: One Zod boundary with Deterministic, NotConfigured (loud, retriable rejection), and Live (raw fetch, injected secrets, no vendor SDK) adapters, selected only by the composition root. - Typed retriable error contract: SendError/ParseError carry retriable and status fields so the consumer routes retries without regexing provider error messages, and poison messages are acked with a loud log. - Use Case: When adding a new queue consumer in workers/agents/ or wiring a Resend/Anthropic/Stripe adapter, apply this recipe so redelivery fast-paths from committed events instead of re-judging or double-sending. ## Quick Start Use this skill to make my new queue consumer agent idempotent with deterministic event ids and a three-adapter port for its email sender.
