API Evangelist enhancements for the Machine Library API

overlay: 1.0.0
info:
  title: API Evangelist enhancements for the Machine Library API
  version: 2026-09-19
  x-generated: '2026-09-19'
  x-method: generated
  x-source: >-
    Generated from artifacts harvested in this repo (rate-limit headers observed live, the error envelope
    observed on a live 401, the x-service-info and llms.txt links the provider publishes, and the terms /
    pricing pages). Applied to openapi/machinelibrary-ai-openapi.yml; the original spec is never mutated.
extends: ../openapi/_original/machinelibrary-ai-openapi.yml
actions:
- target: $.info
  description: Add contact, terms and external docs the provider publishes elsewhere on its site.
  update:
    contact:
      name: Space Frontiers / Machine Library
      url: https://machinelibrary.ai/contacts
      email: contact@machinelibrary.ai
    termsOfService: https://machinelibrary.ai/terms-of-service
    x-pricing: https://api.machinelibrary.ai/v1/pricing
    x-llms-txt: https://machinelibrary.ai/llms.txt
- target: $
  description: Point at the interactive reference (Scalar) and record the well-known discovery surface.
  update:
    externalDocs:
      description: Machine Library API reference (Scalar)
      url: https://machinelibrary.ai/docs/api/reference
    x-well-known:
      api-catalog: https://machinelibrary.ai/.well-known/api-catalog
      oauth-protected-resource: https://machinelibrary.ai/.well-known/oauth-protected-resource
      oauth-authorization-server: https://api.spacefrontiers.org/.well-known/oauth-authorization-server
      agent-card: https://machinelibrary.ai/.well-known/agent-card.json
      mcp-server-card: https://machinelibrary.ai/.well-known/mcp/server-card.json
- target: $.tags
  description: Declare the Payments tag used by createMppBalanceTopUp but missing from the tag list.
  update:
  - name: Payments
    description: Prepaid-credit funding of the account balance through Stripe MPP payment challenges.
- target: $.components
  description: Name the shared error envelope observed live ({"detail":"Unauthorized","status":"error"}) and the rate-limit headers observed on every host.
  update:
    schemas:
      ErrorEnvelope:
        type: object
        required: [detail, status]
        properties:
          detail: {type: string}
          status: {type: string, enum: [error]}
    headers:
      X-RateLimit-Limit:
        description: Requests permitted in the current window (observed 12 on api.machinelibrary.ai unauthenticated, 60 on mcp.machinelibrary.ai, 120 on machinelibrary.ai/a2a).
        schema: {type: integer}
      X-RateLimit-Remaining:
        description: Requests remaining in the current window.
        schema: {type: integer}
      X-RateLimit-Reset:
        description: Seconds until the window resets (observed 0).
        schema: {type: integer}
      X-Request-Id:
        description: Per-request identifier returned by api.machinelibrary.ai and mcp.machinelibrary.ai.
        schema: {type: string, format: uuid}
- target: $.paths.*.*.responses.401
  description: Attach the observed JSON error envelope to every 401 that declares no content.
  update:
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/ErrorEnvelope'
        example: {detail: Unauthorized, status: error}
- target: $.paths.*.*.responses.402
  description: Note that 402 on non-payment operations means insufficient prepaid balance (top up at /payments or via createMppBalanceTopUp); on createMppBalanceTopUp it is the Stripe MPP challenge.
  update:
    x-remediation: Top up the prepaid USD balance at https://machinelibrary.ai/payments, or as an agent call POST /v2/payments/mpp/top-up (ACP checkout sessions also exist at /v2/acp/checkout_sessions).
- target: $.paths['/v1/recognitions'].post
  description: Surface the provider's own idempotency statement from the standalone Recognition spec.
  update:
    x-idempotent: Resubmitting identical content is idempotent and free (Machine Library Recognition API info.description).