generated: '2026-07-19'
method: derived
source: openapi/gray-swan-cygnal-openapi.json + docs.grayswan.ai + trust.grayswan.ai
api: Cygnal
summary: >-
  Standards / cross-cutting conformance assertions for the Cygnal API, derived
  from the OpenAPI and enriched from the docs and trust center. Cygnal's design
  point is wire-compatibility with the major LLM provider request/response
  formats rather than classic web-API standards.
conformance:
  - id: openapi-3.1
    conforms: true
    evidence: Published spec is OpenAPI 3.1.0 at https://api.grayswan.ai/openapi.json
  - id: openai-chat-completions-compat
    conforms: true
    evidence: POST /cygnal/v1/chat/completions mirrors the OpenAI Chat Completions contract (drop-in base URL swap).
  - id: openai-responses-compat
    conforms: true
    evidence: POST /cygnal/responses mirrors the OpenAI Responses API.
  - id: anthropic-messages-compat
    conforms: true
    evidence: POST /cygnal/v1/messages mirrors the Anthropic Messages API.
  - id: gemini-generatecontent-compat
    conforms: true
    evidence: POST /cygnal/v1beta/models/{model}:generateContent mirrors Google Gemini generateContent.
  - id: rfc9457-problem-json
    conforms: false
    evidence: Errors use a custom StandardErrorResponse envelope, not application/problem+json.
  - id: oauth2
    conforms: false
    evidence: API-key auth only (grayswan-api-key header); no OAuth2 flows.
  - id: idempotency
    conforms: false
    evidence: No idempotency key/header documented.
compliance_programs:
  - name: SOC 2 Type 2
    evidence: https://trust.grayswan.ai/
  - name: Cyber Essentials
    evidence: https://trust.grayswan.ai/