We think we’ve seen a change in behaviour of the Create Client endpoint in the management API sometime over the last few days. We have a fix on our side but would like to check with you that our hypothesis about what’s happened are correct.
We’re creating Auth0 non-interactive clients which we expose to end-users as “API Clients” so they can access our public API. This was working fine, but sometime in the last few days new clients that were created didn’t have a client_credentials grant type. This resulted in the following error when users tried to do a client credentials exchange:
“error_description”: “Grant type ‘client_credentials’ not allowed for the client.”
We’re using the Auth0 .net library to access the management API for creation of the clients. We were calling this with just the client name and type, like this:
var res = await auth0ApiClient.Clients.CreateAsync(new ClientCreateRequest
Name = apiClientName,
ApplicationType = ClientApplicationType.NonInteractive
From a combination of network tracing and code review, we discovered that the library is also setting this property: `token_endpoint_auth_method":“none”.
If we set that property to POST on the call above, using TokenEndpointAuthMethod = TokenEndpointAuthMethod.ClientSecretPost then we get the client_credentials grant type and the credentials exchange works fine.
We can’t see anything we’ve changed in this area, and have never had to set this property to create clients that can do successful credentials exchanges. Our hypothesis is that you’ve changed something to be stricter and not allow credentials exchanges if the create_credentials grant type is not present.
Please could you confirm whether this is true and whether we’re missing anything else we should be specifying so we don’t get caught out again?