API Evangelist enhancements for GPT55 Model Gateway API

overlay: 1.0.0
info:
  title: API Evangelist enhancements for GPT55 Model Gateway API
  version: 1.0.0
extends: openapi/558686-xyz-gpt55-model-gateway-openapi.json
x-generated: '2026-09-19'
x-method: generated
x-source: openapi/558686-xyz-gpt55-model-gateway-openapi.json
x-note: Overlay of API Evangelist enhancements; the original spec is never mutated. Actions target the spec verbatim
  as served by the provider on 2026-09-19.
actions:
- target: $.info
  update:
    x-apievangelist:
      catalog: https://apis.io/558686-xyz
      provider: gpt55-token-gateway
      maintainer: Kin Lane <kin@apievangelist.com>
      artifacts:
      - apis.yml
      - a2a/558686-xyz-a2a.yml
      - mcp/558686-xyz-mcp.yml
      - mcp/558686-xyz-tool-crosswalk.yml
      - conventions/558686-xyz-conventions.yml
      - errors/558686-xyz-problem-types.yml
      - rate-limits/558686-xyz-rate-limits.yml
      - plans/558686-xyz-plans-pricing.yml
      - lifecycle/558686-xyz-lifecycle.yml
      - conformance/558686-xyz-conformance.yml
      - authentication/558686-xyz-authentication.yml
      - well-known/558686-xyz-well-known.yml
      - skills/_index.yml
- target: $.components
  update:
    securitySchemes:
      x402Payment:
        type: apiKey
        in: header
        name: X-PAYMENT
        description: x402 v2 exact payment. Call without the header to receive HTTP 402 with a PAYMENT-REQUIRED
          header (base64 JSON) and a JSON body whose accepts[] carries scheme exact, network eip155:8453, asset
          USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, payTo 0x1f0130669ca6fd02e025a984cc038f139df19a2f, amount
          (atomic) and maxTimeoutSeconds 300; retry the SAME request with X-PAYMENT. Observed live 2026-09-20; documented
          at https://gpt55.558686.xyz/buyer-guide. A private Bearer token is an operator-only bypass (see authentication/558686-xyz-authentication.yml).
- target: $.info
  update:
    x-apievangelist-observed:
      rate_limit_headers:
      - 'ratelimit-limit: 120'
      - 'ratelimit-policy: 120;w=60'
      - ratelimit-remaining
      - ratelimit-reset
      exposed_headers:
      - PAYMENT-REQUIRED
      - X-PAYMENT-REQUIRED
      - PAYMENT-RESPONSE
      - X-PAYMENT-RESPONSE
      - x-x402-receipt-id
      - x-x402-receipt-url
      - x-x402-payment-response-omitted
      - x-x402-payment-response-recovery
      - Retry-After
      error_envelope: '{"error":{"message":string,"type":string}} on 400/404; x402 v2 body on 402'
      see:
      - rate-limits/558686-xyz-rate-limits.yml
      - errors/558686-xyz-problem-types.yml
      - conventions/558686-xyz-conventions.yml
- target: $.tags
  update:
  - name: gpt55-model-gateway
    description: Paid GPT model routes, prepaid call packs and model-backed text tools (x402 exact USDC on Base).
  - name: gpt55-retained-nonmodel
    description: 'Deterministic tools retained on the main host after the 2026-07 split: timestamp, query-parse,
      EVM wallet balance, x402 MCP integration kit, x402 Bazaar search, wallet payment activation.'
  - name: gpt55-retained-high-intent
    description: Wallet signing safety pack (GET quote / POST buy).
- target: $.paths.*[?(@.responses['402'])].responses['402']
  update:
    description: 'x402 payment required. Body: {x402Version: 2, error: "Payment required", resource {url, description,
      mimeType, serviceName, tags, category}, accepts [{scheme, network, amount, asset, payTo, maxTimeoutSeconds,
      extra}], extensions.bazaar {info {input, output}, schema}}. Header PAYMENT-REQUIRED carries the same envelope
      base64-encoded.'
    headers:
      PAYMENT-REQUIRED:
        schema:
          type: string
        description: base64 JSON x402 v2 payment requirements
      ratelimit-limit:
        schema:
          type: integer
      ratelimit-remaining:
        schema:
          type: integer
      ratelimit-reset:
        schema:
          type: integer
- target: $.paths['/v1/models'].get
  update:
    x-apievangelist-observed:
      anonymous: true
      status: 200
      note: Answers without payment; seven models with pricing and x402 endpoint metadata per model.