Client Credentials Grant¶
This grant is suitable for machine-to-machine authentication or for a client making requests to an API that does not require the user’s permission. This grant should be allowed for use only by trusted clients.
The client can request an access token using only its client credentials with this grant type. It is similar to the resource owner password credentials grant type except in this case, only the client’s credentials are used to authenticate a request for an access token.
The diagram below illustrates the client credentials grant flow.
The cURL commands below can be used to try this grant type.
curl -v -X POST -H "Authorization: Basic <base64 encoded client id:client secret value>" -k -d "grant_type=client_credentials" -H "Content-Type:application/x-www-form-urlencoded" https://localhost:9443/oauth2/token
curl -u <client id>:<client secret> -k -d "grant_type=client_credentials" -H "Content-Type:application/x-www-form-urlencoded" https://localhost:9443/oauth2/token
You will receive a response similiar to the format below.
Support for refresh token grant - No
This grant type doesn't issue a refresh token, which can be used to obtain new access tokens using the refresh token grant.
See the Try Client Credentials Grant topic to try out a sample of the resource owner password credentials grant with WSO2 Identity Server and WSO2 OAuth2 Playground.