Flatten an OpenAPI 3.x or Swagger 2.x spec into a structured list of callable endpoints — one row per operation with method, path, operationId, summary, tags, parameters (name / in / required / type), JSON-body flag, and documented response codes. Includes per-method and per-tag counts so an agent can pick what to call next without parsing the full spec. Output is sorted by path then method for stable, agent-friendly grouping. Pure CPU — deterministic, no network, no $ref dereferencing.