Topic
The discipline of designing APIs—REST, GraphQL, RPC—and their specifications like OpenAPI, covering request semantics, idempotency, and data contracts.
GitHub added an endpoint that returns up to 30 weeks of daily star counts in one request, with no stargazer identities attached. Its engineering post, headlined "From 2,500 requests to 24," says the old route needed about 2,511 calls for react/react.
Reality
A lost response looks exactly like a failed request from the client. That single ambiguity is why any API that moves money has to treat a duplicate submission as normal traffic.
Reality
The IETF published RFC 10008 in June 2026 and IANA registered QUERY as safe and idempotent, so a structured read no longer has to travel as a POST. Whether the response stays cacheable depends on the caches on the path.
Reality
In a dev.to walkthrough an agent refunds the wrong one of two identical charges, and because the refund service only sees an ID and an amount, the author's fix keys idempotency to the customer's intent instead of the HTTP request.
Reality
Two unauthenticated endpoints on the same store return different variant shapes. Getting the four inventory fields costs one request per product, and one of them answers 999,999 for goods nobody tracks.
Reality
A dev.to costing post puts internal APIs at £10,000 to £30,000 and public ones above £100,000 for much the same endpoints, with the difference sitting in token flows, sandboxes, docs and per-consumer tracing.
Reality
A dev.to walkthrough mints the key once per user intent, caches it on the order view model, and leaves the server to recognize repeats, because a disabled Buy button depends on a run loop that may not run in time.
Reality
The same platform ships regex and BM25 ranking in front of its tool catalog, while its memory store offers only depth, limit, page, path_prefix and view, so ranking memories is work the developer supplies.
Reality
A dev.to walkthrough separates content identity from operation identity: fingerprints catch a changed payload, idempotency keys catch the order created before the response died.
Reality
CircleCI's explainer puts MCP in front of the APIs you already run. The integration work is small; deciding which operations become agent-legible capabilities is not.
Reality