generated: '2026-08-13'
method: probed
source: https://substack.com/.well-known/oauth-authorization-server
docs: https://substack.com/oauth/.well-known/openid-configuration
note: >-
  Substack publishes no human-readable OAuth scope reference. Every scope below was
  read from the provider's own machine-readable discovery documents: the RFC 8414
  Authorization Server Metadata at the host root and the OpenID Connect Discovery
  document at /oauth/.well-known/openid-configuration. The two lists differ — the OIDC
  document additionally advertises apple_podcasts — so the union is recorded with the
  source of each. Descriptions marked derived are inferred from the scope name and the
  corresponding product surface; Substack does not document them.
schemes:
  - name: SubstackOAuth
    type: oauth2
    issuer: https://substack.com
    source: https://substack.com/.well-known/oauth-authorization-server
    flows:
      - flow: authorizationCode
        authorizationUrl: https://substack.com/oauth/auth
        tokenUrl: https://substack.com/oauth/token
        pkce: S256
      - flow: deviceCode
        deviceAuthorizationUrl: https://substack.com/oauth/device/auth
        tokenUrl: https://substack.com/oauth/token
        source: https://substack.com/oauth/.well-known/openid-configuration
      - flow: implicit
        authorizationUrl: https://substack.com/oauth/auth
        source: https://substack.com/oauth/.well-known/openid-configuration
        note: advertised in the OIDC document only; not in the RFC 8414 document
scopes:
  - scope: openid
    description: OpenID Connect authentication; issue an ID token for the signed-in Substack account.
    description_method: derived
    sources: [oauth-authorization-server, openid-configuration]
  - scope: profile
    description: Read the standard OIDC profile claims for the account.
    description_method: derived
    sources: [oauth-authorization-server, openid-configuration]
  - scope: email
    description: Read the account email claim.
    description_method: derived
    sources: [oauth-authorization-server, openid-configuration]
  - scope: offline_access
    description: Issue a refresh token so access can be renewed without re-consent.
    description_method: derived
    sources: [oauth-authorization-server, openid-configuration]
  - scope: mcp:read
    description: >-
      Read-only access through the official Substack MCP server at
      https://mcp.substack.com/api/v1/mcp. This is the only scope the MCP protected
      resource metadata declares as supported.
    description_method: probed
    sources: [oauth-authorization-server, openid-configuration, oauth-protected-resource]
    protected_resource: https://mcp.substack.com/api/v1/mcp
  - scope: notes.read
    description: Read access to Substack Notes.
    description_method: derived
    sources: [oauth-authorization-server, openid-configuration]
    note: >-
      Advertised by the authorization server but not reachable through any documented
      Substack surface — the MCP server's own documentation states it cannot access
      Notes activity, and there is no published Notes REST API. Recorded because the
      provider advertises it, not because a consumer-facing contract exists.
  - scope: notes.write
    description: Write access to Substack Notes.
    description_method: derived
    sources: [oauth-authorization-server, openid-configuration]
    note: >-
      Same as notes.read — advertised in discovery, with no published contract behind
      it. This is the only write scope Substack advertises anywhere.
  - scope: apple_podcasts
    description: Podcast-feed linkage for the Apple Podcasts integration.
    description_method: derived
    sources: [openid-configuration]
    note: present only in the OIDC discovery document, not in the RFC 8414 document
claims_supported:
  - sub
  - name
  - subscription
  - publication_role
  - email
  - publication_id
  - sid
  - auth_time
  - iss
x-evidence:
  - fetched: '2026-08-13'
    url: https://substack.com/.well-known/oauth-authorization-server
    http_status: 200
  - fetched: '2026-08-13'
    url: https://substack.com/oauth/.well-known/openid-configuration
    http_status: 200
  - fetched: '2026-08-13'
    url: https://mcp.substack.com/.well-known/oauth-protected-resource/api/v1/mcp
    http_status: 200