api-integration-engineering

Generates a typed API client from an OpenAPI/Swagger spec, with a hand-controlled transport wrapper for timeouts, auth, and typed errors. Use when integrating a REST API that ships an openapi.yaml/swagger.json, when generating or regenerating a client from a spec, or when a hand-written client keeps drifting from the upstream contract. Do NOT use when the task is the backoff/retry policy itself — use rate-limit-handler instead; do NOT use for cursor pagination or keeping a local copy in sync — use pagination-and-sync-engineer instead.

Produces an API version scheme (date-pinned header or URI), a breaking-vs-additive change policy, and a published deprecation/sunset timeline with translation shims. Use when removing or renaming a field or endpoint, tightening validation, cutting a "v2", binding a partner integration to a version, or planning how long an old version lives. Do NOT use when designing the resource shape, URLs, status codes, or pagination of a new endpoint — use REST API Design instead; this skill owns only the version scheme and deprecation path layered on top of that contract.

Wraps flaky upstream dependencies in circuit breakers, aggressive timeouts, and per-dependency bulkheads so a slow or failing service degrades gracefully instead of cascading into a full outage. Use when a slow or unavailable upstream is stalling your threads, outbound calls hang with no timeout, one dependency's outage is taking down unrelated traffic, or you are integrating a network call that can realistically be slow or down. Do NOT use when the goal is staying under a provider's request quota or handling 429s — use rate-limit-handler instead; do NOT use to size a database connection pool — use connection-pool-tuner instead.

Adds client-supplied idempotency keys and request deduplication so at-least-once delivery and client retries return the first result instead of double-charging or double-shipping. Use when building a write endpoint that triggers payments, orders, emails, or other non-reversible side effects, or before exposing any unsafe POST behind a retrying client or queue. Do NOT use for inbound third-party webhook handlers whose dedup is keyed on a provider event ID — handle those in your webhook receiver and reference this skill for the storage pattern instead.

Build correct cursor pagination and incremental delta sync against a paginated API, handling inserts, deletes, watermarks, resumability, and idempotency. Use when paging a list/changes endpoint, fetching a large dataset, or keeping a local copy in sync — especially when a sync skips or duplicates rows, you have an offset/page=N loop, or you are designing a cursor or updated_at watermark. Do NOT use when generating a typed API client or SDK from a spec — use api-client-generator instead.

Adds retry-with-backoff, Retry-After handling, and client-side throttling so a caller stays under an upstream API's rate limits instead of hammering it. Use when you call a rate-limited or quota-enforced third-party API, see 429 or 503 responses or Retry-After headers, or have a worker fleet that needs to share one upstream's quota. Do NOT use to fail fast when a dependency is down — use circuit-breaker-builder instead; do NOT use to scaffold the HTTP client itself — use api-client-generator instead.

Hardens an inbound webhook endpoint so it verifies the sender signature on the raw body, resists replays, and acknowledges fast by persisting-then-enqueueing before any processing. Use when building or reviewing a handler that receives webhooks from Stripe, GitHub, or any third party, when adding HMAC signature verification, or when a sender is replaying events or hammering you with retries after slow acks.

Design REST APIs that are consistent, discoverable, and easy to consume.