Integration is done and the partner asks for a link. Finish descriptions locally, verify real calls, and publish versioned hosted docs and MCP from the same workspace, with no doc-tool rollout attached.
Inventory APIs get consumed by developers reading docs and by agents discovering tools. Separate web docs, prompt pastes, and hand-written schemas guarantee drift; one OpenAPI file produces both.
A real integration walkthrough: import the vendor OpenAPI file once, let the assistant and your coding agent read the exact contract, and send real requests locally, with no more curl archaeology in chat windows.
The create call returned 200, the detail view 404s, and cancel accepts an illegal state. Scenario tests chain real calls, pass data between steps, and hand the agent evidence to fix with.
A concrete sprint diary: one OpenAPI file drove a local mock with latency and error overrides, a four-step checkout scenario with an HTML report, live docs, derived database tables and a hosted MCP endpoint while the real API did not exist yet.
Fake objects in components demo well and integrate badly. Agree on the coupon validation contract first, then let a spec-driven mock answer real HTTP while the service is still being built.
Generated screens fail on limit versus pageSize, data.records versus data.items, cents versus dollars. The fix is not a better prompt; it is letting the agent query the real contract and verify against real responses.
A request that runs is the start of a handoff, not the end of one. Import the curl, capture the missing context, and promote what you learned back into the specification.
Real systems are multi-protocol: REST at the edge, WebSockets for events, gRPC between services, GraphQL at the gateway. Powerduck debugs all of them from the same workspace and the same spec.
The field changed in code, in chat, and in the HTTP client while the docs waited for someone to care. A local OpenAPI file in version control gives the whole team one contract to diff, review, and trust.
Postman collections, mock servers, docs generators and MCP glue all drift the moment the spec stops being the source of truth. Powerduck keeps one local OpenAPI file at the center.
