[SOLVED] Request oAuth token with POST and json body in authlib possible?

Request oAuth token with POST and json body in authlib possible?

My oAuth2 Service requires me to request the Access Token not via GET, but POST and sending the client_id, client_secret and token_endpoint in a JSON body.

According to the docs, authlib seems to support POST authentication requests. However, the following code does still return "invalid request" (while a manually formed request with postman succeeds):

session = OAuth2Session(
    settings.SECURE_M2M_CLIENT_ID, settings.SECURE_M2M_CLIENT_SECRET,
    token_endpoint_auth_method="client_secret_post"
)
token = session.fetch_token(settings.SECURE_M2M_TOKEN_ENDPOINT, verify=False)

Solution

A standard client_secret_post will send in form-encoded body. Your case can be done with a custom authenticate method, you can learn from here: https://docs.authlib.org/en/latest/client/oauth2.html?highlight=token_endpoint_auth_method#client-authentication

e.g. you can call your method: client_secret_json_post.