OAuth API methods

Generate and manage OAuth tokens.

Authorize a user

GET /oauth/authorize HTTP/1.1

Displays an authorization form to the user. If approved, it will create and return an authorization code, then redirect to the desired redirect_uri, or show the authorization code if urn:ietf:wg:oauth:2.0:oob was requested. The authorization code can be used while requesting a token to obtain access to user-level methods.

Returns: String (URL) or HTML response
OAuth: Public
Version history:
0.1.0 - added
2.6.0 - added force_login
3.5.0 - added lang 4.3.0 - added support for PKCE parameters

Request

Query parameters

response_type: required String. Should be set equal to code.
client_id: required String. The client ID, obtained during app registration.
redirect_uri: required String. Set a URI to redirect the user to. If this parameter is set to urn:ietf:wg:oauth:2.0:oob then the authorization code will be shown instead. Must match one of the redirect_uris declared during app registration.
scope: String. List of requested OAuth scopes, separated by spaces (or by pluses, if using query parameters). Must be a subset of scopes declared during app registration. If not provided, defaults to read.
state: String. Arbitrary value to passthrough to your server when the user authorizes or rejects the authorization request.
code_challenge: String. The PKCE code challenge for the authorization request.
code_challenge_method: String. Must be S256, as this is the only code challenge method that is supported by Mastodon for PKCE.
force_login: Boolean. Forces the user to re-login, which is necessary for authorizing with multiple accounts from the same instance.
lang: String. The ISO 639-1 two-letter language code to use while rendering the authorization form.

Response

200: OK

The authorization code will be returned as a query parameter named code.

Treat the code query parameter as if it were a password, you should ensure that it is not logged in request logs.

redirect_uri?code=qDFUEaYrRK5c-HNmTCJbAzazwLRInJ7VHFat0wcMgCU

If the state parameter was used, then this will also be present in the URI when the client is redirected.

redirect_uri?code=qDFUEaYrRK5c-HNmTCJbAzazwLRInJ7VHFat0wcMgCU&state=example

400: Client error

If the authorization code is incorrect or has been used already, the request will fail.

{
  "error": "invalid_grant",
  "error_description": "The provided authorization grant is invalid, expired, revoked, does not match the redirection URI used in the authorization request, or was issued to another client."
}

Obtain a token

POST /oauth/token HTTP/1.1

Obtain an access token, to be used during API calls that are not public.

Returns: Token
OAuth: Public
Version history:
0.1.0 - added 4.3.0 - added support for PKCE parameter

Request

Form data parameters

grant_type: required String. Set equal to authorization_code if code is provided in order to gain user-level access. Otherwise, set equal to client_credentials to obtain app-level access only.
code: required String. A user authorization code, obtained from the redirect after an Authorization request is approved. May alternatively be displayed to the user if urn:ietf:wg:oauth:2.0:oob is used as the redirect_uri.
client_id: required String. The client ID, obtained during app registration.
client_secret: required String. The client secret, obtained during app registration.
redirect_uri: required String. Must match the redirect_uri used during the Authorization request.
code_verifier: String. Required if PKCE is used during the authorization request. This is the code verifier which was used to create the code_challenge using the code_challenge_method for the authorization request.
scope: String. When grant_type is set to client_credentials, the list of requested OAuth scopes, separated by spaces (or pluses, if using query parameters). Must be a subset of the scopes requested at the time the application was created. If omitted, it defaults to read. Has no effect when grant_type is authorization_code.

Response

200: OK

Store this access_token for later use with methods that require authentication. The token should be passed as an HTTP Authorization header when making API calls, with the value Bearer <access_token>

Treat the access_token as if it were a password. We recommend you encrypt this value when storing in your cache, to prevent credential exposure.

Additionally, you should ensure that the code parameter is not logged.

{
  "access_token": "ZA-Yj3aBD8U8Cm7lKUp-lm9O9BmDgdhHzDeqsY8tlL0",
  "token_type": "Bearer",
  "scope": "read write follow push",
  "created_at": 1573979017
}

400: Client error

If you try to request a scope that was not included when registering the app, the request will fail.

{
  "error": "invalid_scope",
  "error_description": "The requested scope is invalid, unknown, or malformed."
}

401: Unauthorized

If client_id and client_secret do not match or are invalid, the request will fail.

{
  "error": "invalid_client",
  "error_description": "Client authentication failed due to unknown client, no client authentication included, or unsupported authentication method."
}

Revoke a token

POST /oauth/revoke HTTP/1.1

Revoke an access token to make it no longer valid for use.

Returns: Empty
OAuth: Public
Version history:
0.1.0 - added

Request

Form data parameters

client_id: required String. The client ID, obtained during app registration.
client_secret: required String. The client secret, obtained during app registration.
token: required String. The previously obtained token, to be invalidated.

Response

200: OK

If you own the provided token, the API call will provide an empty response. This operation is idempotent, so calling this API multiple times will still return OK.

{}

403: Forbidden

If you provide a token you do not own, or no token at all, the API call will return a 403 error.

{
  "error": "unauthorized_client",
  "error_description": "You are not authorized to revoke this token"
}

Discover OAuth Server Configuration

GET /.well-known/oauth-authorization-server HTTP/1.1

Returns the OAuth 2 Authorization Server Metadata for the Mastodon server, as defined by RFC 8414.

We include the additional non-standard property of app_registration_endpoint which refers to the POST /api/v1/apps endpoint, since we don’t currently support the standard registration_endpoint endpoint for Dynamic Client Registration.

The properties exposed by this endpoint can help you better integrate with the Mastodon API, such as allowing for negotiation of scopes across different versions of Mastodon.

Example: You want to use the profile scope, but also want to support older Mastodon servers that don’t have that scope and would need read:accounts instead. You could discover whether a server supports that scope by making a request to this endpoint.

Returns: JSON as per the above description
OAuth: Public
Version history:
4.3.0 - added

Response

200: OK

{
  "issuer": "https://social.example/",
  "service_documentation": "https://docs.joinmastodon.org/",
  "authorization_endpoint": "https://social.example/oauth/authorize",
  "token_endpoint": "https://social.example/oauth/token",
  "app_registration_endpoint": "https://social.example/api/v1/apps",
  "revocation_endpoint": "https://social.example/oauth/revoke",
  "scopes_supported": [
    "read",
    "write",
    "write:accounts",
    "write:blocks",
    "write:bookmarks",
    "write:conversations",
    "write:favourites",
    "write:filters",
    "write:follows",
    "write:lists",
    "write:media",
    "write:mutes",
    "write:notifications",
    "write:reports",
    "write:statuses",
    "read:accounts",
    "read:blocks",
    "read:bookmarks",
    "read:favourites",
    "read:filters",
    "read:follows",
    "read:lists",
    "read:mutes",
    "read:notifications",
    "read:search",
    "read:statuses",
    "follow",
    "push",
    "profile",
    "admin:read",
    "admin:read:accounts",
    "admin:read:reports",
    "admin:read:domain_allows",
    "admin:read:domain_blocks",
    "admin:read:ip_blocks",
    "admin:read:email_domain_blocks",
    "admin:read:canonical_email_blocks",
    "admin:write",
    "admin:write:accounts",
    "admin:write:reports",
    "admin:write:domain_allows",
    "admin:write:domain_blocks",
    "admin:write:ip_blocks",
    "admin:write:email_domain_blocks",
    "admin:write:canonical_email_blocks"
  ],
  "response_types_supported": ["code"],
  "response_modes_supported": ["query", "fragment", "form_post"],
  "code_challenge_methods_supported": [
    "S256"
  ],
  "grant_types_supported": [
    "authorization_code",
    "client_credentials"
  ],
  "token_endpoint_auth_methods_supported": [
    "client_secret_basic",
    "client_secret_post"
  ]
}

Older Mastodon Versions – 404: Not Found

On Mastodon versions before 4.3.0, requesting this endpoint will result in a 404 Not Found error.

Instead, you will need to “guess” what that server supports, instead of discovering supported OAuth 2 endpoints, grant flows & scopes dynamically.

You may want to fallback to the Instance Metadata endpoint to try to discover what Mastodon version the server is running by parsing the version field; however, this is very brittle and not recommended.

OAuth API methods

Authorize a user

Request

Query parameters

Response

200: OK

400: Client error

Obtain a token

Request

Form data parameters

Response

200: OK

400: Client error

401: Unauthorized

Revoke a token

Request

Form data parameters

Response

200: OK

403: Forbidden

Discover OAuth Server Configuration

Response

200: OK

Older Mastodon Versions – 404: Not Found

See also