Ironfang Authentication

generated: '2026-09-02'
method: searched
source: https://ironfang.uk/renderwolf/docs#auth
docs: https://ironfang.uk/renderwolf/docs#auth
derived_from: openapi/ironfang-openapi.yaml
summary:
  types:
    - http
    - oauth2
  note: >-
    Two distinct credentials serve two distinct surfaces. The REST API takes a long-lived
    bearer API key minted in the portal. The MCP server refuses API keys outright and takes
    only a short-lived OAuth 2.1 access token from id.ironfang.uk. Ironfang states each
    surface rejects the other's token.
schemes:
  - name: apiKey
    type: http
    scheme: bearer
    surface: REST
    description: 'An API key from the portal, sent as `Authorization: Bearer <key>`.'
    key_management:
      created_at: https://portal.ironfang.uk
      shown_once: true
      storage: hashed - a lost key is replaced, never recovered
      revocable: true
    scoped: true
    scope_note: >-
      Key scopes are chosen at creation and cannot be widened afterwards; broader access
      requires a new key. Keys minted before scopes existed carry no scopes and retain full
      access for backward compatibility. A call outside the key's scopes returns
      403 insufficient_scope naming the missing scope.
    failure_codes:
      - status: 401
        code: invalid_api_key
        meaning: missing or unrecognised key
      - status: 403
        code: insufficient_scope
        meaning: key does not carry the scope the operation needs
    sources:
      - openapi/ironfang-openapi.yaml
      - https://ironfang.uk/renderwolf/docs#auth
  - name: ironfangOAuth
    type: oauth2
    surface: MCP
    description: >-
      OAuth 2.1 authorization-code flow with PKCE (S256) against id.ironfang.uk, used only by
      MCP clients reaching https://mcp.ironfang.uk/mcp. The access token is audience-bound to
      the MCP resource; product calls are made with a separate two-minute delegated token
      minted per call.
    issuer: https://id.ironfang.uk
    flows:
      authorizationCode:
        authorizationUrl: https://id.ironfang.uk/oauth/authorize
        tokenUrl: https://id.ironfang.uk/oauth/token
        refreshUrl: https://id.ironfang.uk/oauth/token
    discovery:
      protected_resource: https://mcp.ironfang.uk/.well-known/oauth-protected-resource
      authorization_server: https://id.ironfang.uk/.well-known/oauth-authorization-server
      openid_configuration: https://id.ironfang.uk/.well-known/openid-configuration
      jwks_uri: https://id.ironfang.uk/oauth/jwks
      registration_endpoint: https://id.ironfang.uk/oauth/register
    client_identification:
      - Client ID Metadata Document (CIMD) - an HTTPS URL as the client id; preferred
      - public Dynamic Client Registration with PKCE
    grant_types:
      - authorization_code
      - refresh_token
      - client_credentials
      - 'urn:ietf:params:oauth:grant-type:token-exchange'
    pkce: S256
    resource_indicator: 'resource=https://mcp.ironfang.uk/mcp (RFC 8707)'
    token_lifetime: short-lived, rotating refresh token; revocation ends access within 30 seconds
    tenancy: one connection is one person, one organisation, one client
    live_scope_check: >-
      A scope is re-checked against the person's organisation permission on every call - losing
      a permission ends access the same minute.
    sources:
      - well-known/ironfang-oauth-protected-resource.json
      - well-known/ironfang-oauth-authorization-server.json
      - https://ironfang.uk/docs/mcp
signed_urls:
  description: >-
    A third, credential-free access path. POST /v1/sign mints a GET URL whose HMAC signature
    covers every parameter and the metering account, so it can be embedded in an <img> or
    og:image tag without exposing the API key.
  operations:
    - createSignedUrl
    - renderSignedUrl
  ttl: ttl_hours, 0 = never expires (REST); MCP refuses permanent links and caps at 24 hours
  failure_code: 403 bad_signature
x-findings:
  - id: key-prefix-disagreement
    detail: >-
      The published OpenAPI's info.description documents the key prefix as `rw_live_...`, while
      the API reference at ironfang.uk/renderwolf/docs and the renderwolf-cli README both
      document `if_live_...`. Recorded, not resolved - a consumer reading only the contract gets
      the wrong prefix.
    evidence:
      - https://api.ironfang.uk/openapi.yaml
      - https://ironfang.uk/renderwolf/docs
      - https://raw.githubusercontent.com/ironfang-ltd/renderwolf-cli/main/README.md
  - id: oauth-absent-from-contract
    detail: >-
      The OpenAPI declares only the apiKey bearer scheme. The OAuth 2.1 model that governs the
      MCP surface is documented in prose and in the two well-known documents, but appears in no
      machine-readable contract.