generated: '2026-09-19'
method: probed
source: probed /.well-known/ on the Signal AI API, MCP, auth and marketing hosts
notes: 'Signal AI serves NO /.well-known/ document from its API host or its marketing host — every path
  404s there. The real well-known surface is on the MCP host: https://mcp.signal-ai.com serves both RFC
  9728 OAuth protected-resource metadata and RFC 8414 authorization-server metadata anonymously, and answers
  an unauthenticated MCP call with a spec-correct `WWW-Authenticate: Bearer resource_metadata=...` challenge
  pointing at that document. The auth host (Keycloak) serves standard OIDC discovery.'
hosts:
- host: https://mcp.signal-ai.com
  documents:
  - path: /.well-known/oauth-protected-resource
    status: 200
    content_type: application/json
    file: signal-ai-oauth-protected-resource.json
    note: RFC 9728. Declares resource https://mcp.signal-ai.com, authorization server https://login.signal-ai.com/auth/realms/signal,
      and scopes_supported [openid, mcp:tools, offline_access].
  - path: /.well-known/oauth-authorization-server
    status: 200
    content_type: application/json
    file: signal-ai-oauth-authorization-server.json
    note: RFC 8414. Keycloak realm `signal`; grant types include client_credentials and authorization_code
      with PKCE (S256).
  - path: /.well-known/agent-card.json
    status: 401
    note: Not an A2A agent card — the host's blanket JWT gate answers every unmatched path with {"error":"Jwt
      is missing"}. No agent card asserted.
- host: https://login.signal-ai.com
  documents:
  - path: /auth/realms/signal/.well-known/openid-configuration
    status: 200
    file: signal-ai-openid-configuration.json
    note: Keycloak realm OIDC discovery backing the OAuth2 client-credentials flow.
  - path: /.well-known/oauth-authorization-server/auth/realms/signal
    status: 200
    file: signal-ai-login-oauth-authorization-server.json
    bytes: 6909
  path_echo_control: passed
- host: https://api.signal-ai.com
  documents:
  - path: /.well-known/security.txt
    status: 404
  - path: /.well-known/openid-configuration
    status: 404
  - path: /.well-known/oauth-authorization-server
    status: 404
  - path: /.well-known/api-catalog
    status: 404
  - path: /.well-known/agent-card.json
    status: 404
  - path: /.well-known/agent.json
    status: 404
  - path: /llms.txt
    status: 404
  - path: /openapi.json
    status: 200
    content_type: application/json
    file: ../openapi/_original/signal-ai-openapi-original.json
    note: The API self-publishes its full OpenAPI 3.1.0 at the host root instead of under /.well-known/.
- host: https://signal-ai.com
  documents:
  - path: /.well-known/security.txt
    status: 404
  - path: /.well-known/agent-card.json
    status: 404
  - path: /.well-known/agent.json
    status: 404
  - path: /llms.txt
    status: 200
    content_type: text/plain
    file: ../llms/signal-ai-llms.txt
    note: Provider-published llms.txt, saved verbatim. Not a /.well-known/ path but recorded here as part
      of the same discovery sweep.
x-mcp-probe:
  probed: '2026-09-19'
  issue: roadmap#321, roadmap#337
  documents:
  - host: https://login.signal-ai.com
    path: /.well-known/oauth-authorization-server/auth/realms/signal
    file: signal-ai-login-oauth-authorization-server.json
  validated_on: resource (RFC 9728) / issuer (RFC 8414, OIDC)
  negative_control: one per host; a 2xx JSON object at an impossible path discards the host
note: 'MCP-host OAuth discovery added 2026-09-19 (roadmap#321/#337): the harvest visits a provider''s
  primary hosts, and RFC 9728 protected-resource metadata lives on the MCP host, so these documents existed
  and were invisible to the scorer. Fetched live and validated on `resource`/`issuer`; one negative control
  per host.'