OpenAPI Spec Designer

Generate an OpenAPI 3.0 YAML specification for the following endpoints: [ENDPOINT_LIST]. For each, define: 1) HTTP method and path, 2) Query/path parameters, 3) Request body schema (JSON), 4) Response schemas (200 success, 400 validation, 401 unauthorized, 500 error), 5) Security schemes (Bearer Token), 6) Example mock payloads.