WSO2 Identity server supports all grant types those are defined in oAuth2 core specification Four grant types: Authorization Code Grant Implicit Grant Resource Owner Password Credentials Grant (password) Client Credentials Grant We cannot use curl command directly to get an access token for Authorization code grant type and Implicit grant type. I'm going through other two grant types one by one and provide the curl command to get access token. 3. Get access token using password grant type curl -k -d "grant_type=password&username=admin&password=admin" -H "Authorization: Basic ME5fbXdWRXpTVnhfalJIbDV2cmc4RHIycHZBYTp0RmZjcHVFRFM5V1d2eFFEc1ZCd0tWVGd0dE1h, Content-Type: application/x-www-form-urlencoded" https://localhost:9443/oauth2/token ME5fbXdWRXpTVnhfalJIbDV2cmc4RHIycHZBYTp0RmZjcHVFRFM5V1d2eFFEc1ZCd0tWVGd is the encoded value of 0N_mwVEzSVx_jRHl5vrg8Dr2pvAa:tFfcpuEDS9WWvxQDsVBwKVTgttMa (<client_id>:<client_secret>). these