OAuth 2.0
Casdoor issues access tokens for authenticating clients. This page describes how to get a token via the API, verify it, and use it. Alternatively use Casdoor SDKs to handle the flow.
Supported grant types:
| Grant Type | RFC | Use Case |
|---|---|---|
| Authorization Code | RFC 6749 §4.1 | Default; web/mobile apps with a backend. Enabled by default. |
| Implicit | RFC 6749 §4.2 | Frontend-only apps without a backend. |
| Resource Owner Password | RFC 6749 §4.3 | Apps with no frontend redirect; user credentials sent directly. |
| Client Credentials | RFC 6749 §4.4 | Service-to-service calls with no user involved. |
| Refresh Token | RFC 6749 §6 | Renew an access token without re-authenticating. |
| Device Authorization | RFC 8628 | Devices with limited input or no browser. |
| Token Exchange | RFC 8693 | Swap an existing token for one with different scope or audience. |
| JWT Bearer | RFC 7523 | Service auth using a signed JWT assertion instead of a client secret. |
Enable non-default grant types on the application edit page.

Authorization code grant
Redirect the user to:
https://<CASDOOR_HOST>/login/oauth/authorize?
client_id=CLIENT_ID&
redirect_uri=REDIRECT_URI&
response_type=code&
scope=openid&
state=STATE
Scopes
| Scope | Descrição |
|---|---|
| openid (default) | sub, iss, aud |
| profile | name, displayName, avatar |
| email address | |
| address | address (OIDC object in JWT-Standard; see OIDC address claim) |
| phone | phone number |
%20:https://<CASDOOR_HOST>/login/oauth/authorize?
client_id=...&
scope=openid%20email
See the OIDC spec for details.
After the user signs in, Casdoor redirects to:
https://REDIRECT_URI?code=CODE&state=STATE
Exchange the code for tokens with a POST to:
https://<CASDOOR_HOST>/api/login/oauth/access_token
Request body:
{
"grant_type": "authorization_code",
"client_id": ClientId,
"client_secret": ClientSecret,
"code": Code,
}
Example response:
{
"access_token": "eyJhb...",
"id_token": "eyJhb...",
"refresh_token": "eyJhb...",
"token_type": "Bearer",
"expires_in": 10080,
"scope": "openid"
}
Casdoor supports PKCE (Proof Key for Code Exchange) for enhanced security. To enable PKCE, add two parameters when requesting the authorization code:
&code_challenge_method=S256&code_challenge=YOUR_CHALLENGE
The code challenge should be a Base64-URL-encoded SHA-256 hash of your randomly generated code verifier (43-128 characters). When requesting the token, include the original code_verifier parameter. With PKCE enabled, client_secret becomes optional, but if provided, it must be correct.
For OAuth providers configured in Casdoor (like Twitter and custom providers with PKCE enabled), Casdoor automatically generates unique code verifiers for each authentication flow, so you don't need to manually implement PKCE.
Binding Tokens to Specific Services
When your application needs to call multiple backend services, you might want tokens that are explicitly bound to a specific service. This prevents security issues where a token meant for one service could accidentally be used with another.
Casdoor supports RFC 8707 Resource Indicators, which lets you specify the intended service when requesting authorization. Add the resource parameter with an absolute URI identifying your service:
https://<CASDOOR_HOST>/login/oauth/authorize?
client_id=CLIENT_ID&
redirect_uri=REDIRECT_URI&
response_type=code&
scope=openid&
state=STATE&
resource=https://api.example.com
When you exchange the authorization code for tokens, include the same resource parameter:
{
"grant_type": "authorization_code",
"client_id": ClientId,
"client_secret": ClientSecret,
"code": Code,
"resource": "https://api.example.com"
}
The resulting access token will have its aud (audience) claim set to your resource URI instead of the client ID. Your backend service can then verify that tokens were issued specifically for it by checking the audience claim. The resource must match exactly between the authorization and token requests.
The resource parameter is preserved through browser-based login flows. If a user needs to complete an interactive login (e.g. password entry, MFA, or WebAuthn), the parameter is carried through the entire redirect chain and included when the authorization code is issued.
provider_hint parameter
To skip the Casdoor login page and send the user directly to a specific OAuth provider, add provider_hint=<provider-name> to the authorize URL:
https://<CASDOOR_HOST>/login/oauth/authorize?
client_id=CLIENT_ID&
redirect_uri=REDIRECT_URI&
response_type=code&
scope=openid&
state=STATE&
provider_hint=github
Casdoor serves a lightweight redirect page (without loading the full React app) that immediately bounces the user to that provider's OAuth flow. This reduces time-to-redirect on constrained devices or slow connections.
Signup Flow with OAuth
When users sign up through the OAuth authorization flow, they are automatically redirected to your application's callback URL with the authorization code, just like the sign-in flow. Previously, users had to manually click through intermediate pages after creating their account. Now the signup process matches the streamlined experience of signing in—once registration completes, Casdoor immediately generates the authorization code and redirects to your redirect_uri.
Your application doesn't need any changes to support this. The authorization parameters (client_id, response_type, redirect_uri, etc.) are automatically passed through the signup process when users choose to create a new account during OAuth authorization.
Implicit Grant
For apps without a backend, use Implicit Grant. Enable it on the application, then redirect users to:
The Implicit Grant token endpoint requires a valid username and password. Pure OAuth users (accounts created exclusively via a third-party provider with no local password set) cannot use this flow and will receive invalid_grant. Use the Authorization Code flow for social-login users.
https://<CASDOOR_HOST>/login/oauth/authorize?client_id=CLIENT_ID&redirect_uri=REDIRECT_URI&response_type=token&scope=openid&state=STATE
Após seu usuário se autenticar com o Casdoor, o Casdoor irá redirecioná-lo para:
https://REDIRECT_URI/#access_token=ACCESS_TOKEN
O Casdoor também suporta o id_token como response_type, que é um recurso do OpenID.
Device Grant
For devices with limited input or no browser, use Device Grant. Enable it on the application, request device_authorization_endpoint from OIDC discovery, then show verification_uri (e.g. via QR or text) so the user can complete login.
Second, you should request token endpoint to get Access Token with parameter define in rfc8628.
Resource Owner Password Credentials Grant
Se sua aplicação não tem um frontend que redireciona os usuários para o Casdoor, então você pode precisar disso.
Enable Password Credentials Grant on the application, then send a POST request to:
https://<CASDOOR_HOST>/api/login/oauth/access_token
{
"grant_type": "password",
"client_id": ClientId,
"client_secret": ClientSecret,
"username": Username,
"password": Password,
}
Example response:
{
"access_token": "eyJhb...",
"id_token": "eyJhb...",
"refresh_token": "eyJhb...",
"token_type": "Bearer",
"expires_in": 10080,
"scope": "openid"
}
Client Credentials Grant
Use Client Credentials Grant when the application has no frontend.
Enable Client Credentials Grant on the application and send a POST request to https://<CASDOOR_HOST>/api/login/oauth/access_token:
{
"grant_type": "client_credentials",
"client_id": ClientId,
"client_secret": ClientSecret,
}
Example response:
{
"access_token": "eyJhb...",
"id_token": "eyJhb...",
"refresh_token": "eyJhb...",
"token_type": "Bearer",
"expires_in": 10080,
"scope": "openid"
}
É importante notar que o AccessToken obtido desta forma difere dos três primeiros, pois corresponde à aplicação e não ao usuário.
Refresh Token
To refresh the access token, use the refreshToken obtained above.
Set the Refresh Token expiration in the application (default 0 hours), then send a POST request to https://<CASDOOR_HOST>/api/login/oauth/refresh_token
{
"grant_type": "refresh_token",
"refresh_token": REFRESH_TOKEN,
"scope": SCOPE,
"client_id": ClientId,
"client_secret": ClientSecret,
}
Example response:
{
"access_token": "eyJhb...",
"id_token": "eyJhb...",
"refresh_token": "eyJhb...",
"token_type": "Bearer",
"expires_in": 10080,
"scope": "openid"
}
Token Exchange Grant
Token Exchange (RFC 8693) lets you swap an existing token for a new one with different characteristics—particularly useful when one service needs to call another on behalf of a user, or to narrow a token's scope for a specific downstream service.
To exchange a token, send a POST request to https://<CASDOOR_HOST>/api/login/oauth/access_token:
{
"grant_type": "urn:ietf:params:oauth:grant-type:token-exchange",
"client_id": ClientId,
"client_secret": ClientSecret,
"subject_token": SubjectToken,
"subject_token_type": "urn:ietf:params:oauth:token-type:access_token",
"scope": "openid email"
}
The subject_token is the token you want to exchange—typically an access token or JWT you already have. If you want to narrow the permissions in the new token, specify a scope that's a subset of the original token's scope. When you omit scope, the new token inherits the same scope as the subject token.
Casdoor supports three token types for subject_token_type:
urn:ietf:params:oauth:token-type:access_token(default)urn:ietf:params:oauth:token-type:jwturn:ietf:params:oauth:token-type:id_token
The response returns a new token tied to the same user as your subject token:
{
"access_token": "eyJhb...",
"id_token": "eyJhb...",
"refresh_token": "eyJhb...",
"token_type": "Bearer",
"expires_in": 10080,
"scope": "openid email"
}
For example, an API gateway might exchange a broad-scoped access token for a narrower one before forwarding requests to a downstream microservice. This pattern—called scope downscoping—ensures each service gets only the permissions it needs, rather than inheriting full access from the original token.
JWT Bearer Grant
JWT Bearer (RFC 7523) allows a client to obtain an access token by presenting a signed JWT assertion instead of a client secret. This is useful for service-to-service calls where the client holds a private key and wants to authenticate without sharing a long-lived secret.
Enable JWT Bearer on the application, then upload the client's certificate in the Client cert field under the Security tab. Casdoor uses the public key from that certificate to verify the JWT assertion.
Send a POST request to https://<CASDOOR_HOST>/api/login/oauth/access_token:
{
"grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
"client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
"client_assertion": "<signed-JWT>",
"client_id": "CLIENT_ID"
}
The JWT assertion (client_assertion) must be signed with the client's private key and contain:
| Claim | Description |
|---|---|
iss | Issuer — the client_id of the application |
sub | Subject — the client_id of the application |
aud | Audience — the Casdoor token endpoint URL |
exp | Expiry time (Unix timestamp) |
Casdoor verifies the signature against the public key in the application's Client cert, checks the standard JWT claims, and—if valid—returns an access token tied to the application (same behavior as the Client Credentials grant).
Example response:
{
"access_token": "eyJhb...",
"token_type": "Bearer",
"expires_in": 10080,
"scope": "openid"
}
Como Verificar Access Token
O Casdoor atualmente suporta o endpoint de introspecção de token. Este endpoint é protegido por Autenticação Básica (ClientId:ClientSecret).
POST /api/login/oauth/introspect HTTP/1.1
Host: CASDOOR_HOST
Accept: application/json
Content-Type: application/x-www-form-urlencoded
Authorization: Basic Y2xpZW50X2lkOmNsaWVudF9zZWNyZXQ=
token=ACCESS_TOKEN&token_type_hint=access_token
Example response:
{
"active": true,
"client_id": "c58c...",
"username": "admin",
"token_type": "Bearer",
"exp": 1647138242,
"iat": 1646533442,
"nbf": 1646533442,
"sub": "7a6b4a8a-b731-48da-bc44-36ae27338817",
"aud": [
"c58c..."
],
"iss": "http://localhost:8000"
}
Como Usar AccessToken
Use the access token to call Casdoor APIs that require authentication.
Por exemplo, existem duas maneiras diferentes de solicitar /api/userinfo.
Tipo 1: Parâmetro de consulta
https://CASDOOR_HOST/api/userinfo?accessToken=your_access_token
Tipo 2: Token Bearer HTTP
https://CASDOOR_HOST/api/userinfo with the header: "Authorization: Bearer your_access_token"
O Casdoor irá analisar o access_token e retornar as informações do usuário correspondentes de acordo com o scope. The response has the same shape:
{
"sub": "7a6b4a8a-b731-48da-bc44-36ae27338817",
"iss": "http://localhost:8000",
"aud": "c58c..."
}
If you expect more user information, add scope when obtaining the AccessToken in step Authorization code grant.
Accessing OAuth Provider Tokens
When users sign in via OAuth providers (GitHub, Google, etc.), the provider's access token is available to call the third-party API on their behalf; it is stored in the user's originalToken field.
The token is available through the /api/get-account endpoint:
{
"status": "ok",
"data": {
"name": "user123",
"originalToken": "ya29.a0AfH6SMBx...",
...
}
}
The originalToken is visible only when the user requests their own account or when the requester is an admin. For other requests, it is masked for privacy.
This allows your application to interact with third-party APIs (e.g., GitHub API, Google Drive API) using the provider's access token without requiring additional OAuth flows.
Diferenças entre as APIs userinfo e get-account
-
/api/userinfo: Esta API retorna informações do usuário como parte do protocolo OIDC. Ela fornece informações limitadas, incluindo apenas as informações básicas definidas nos padrões OIDC. For a list of available scopes supported by Casdoor, see the Scopes section. -
/api/get-account: Esta API recupera o objeto do usuário para a conta atualmente logada. It is a Casdoor-specific API that allows you to obtain all the information of the user in Casdoor, including the OAuth provider's access token when applicable.