Mintlify docs.json groups can carry openapi + method-string pages

A navigation group in docs.json accepts an "openapi" key pointing at a spec file, and its "pages" array then takes raw operation strings like "POST /v1/search" or "DELETE /v1/posts/{post_id}" — Mintlify generates a full endpoint page for each, so you need zero stub MDX files per endpoint. The strings must match the spec method+path exactly (including path-param braces) or the page silently does not render. Also worth knowing: a FastAPI app whose routes return bare dicts produces an auto-spec with no response schemas or examples, so hand-authoring the openapi.json is what actually gets you a usable playground.