We’ve just enabled SAML SSO for our org and now our internal tools are getting locked out. The docs say programmatic access should work fine via the standard OAuth2 client credentials grant, but I’m hitting a wall.
POST /oauth/token
Host: api.mypurecloud.com
Authorization: Basic <base64(client_id:client_secret)>
Content-Type: application/x-www-form-urlencoded
grant_type=client_credentials&scope=admin:queue:read
I get a 401 Unauthorized back. The error payload just says "error": "invalid_grant" with no useful details. I’ve double-checked the client ID and secret in the Admin UI > Integrations > OAuth Apps section. They match. The app has the admin:queue:read scope assigned.
Is there a specific flag I need to toggle in the SAML configuration to allow machine-to-machine auth? Or did we break something in the trust chain? I’m not trying to log in as a user, just get a token for a service account. This was working perfectly before the SAML switch. Now it’s dead.
I’ve been down this exact rabbit hole with a hybrid setup last month. The 401 isn’t always about the credentials being wrong. It’s often the scope definition in the OAuth client config that gets silently ignored after SAML is toggled on, or the client was created before the SAML trust was established and needs a refresh.
Check the OAuth client in the admin console. Make sure the client_type is set to confidential and that the specific scopes you’re requesting (admin:queue:read in your case) are explicitly checked in the client’s scope list, not just assumed from the user’s role. SAML doesn’t care about user roles for machine-to-machine auth, so if the scope isn’t bound to the client, the token endpoint rejects it.
Also, verify you’re using the correct environment endpoint. If your SAML setup points to a specific region (like api.ca..com), ensure your curl host matches that exactly. A mismatch there throws a 401 because the token service can’t validate the client ID against the expected region metadata.
Here’s a slightly more verbose curl that helps debug the exact error message Genesys returns, which is usually more helpful than just “Unauthorized”:
curl -X POST "https://api.mypurecloud.com/oauth/token" \
-H "Authorization: Basic $(echo -n 'YOUR_CLIENT_ID:YOUR_CLIENT_SECRET' | base64)" \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "grant_type=client_credentials&scope=admin:queue:read" \
-v
Look at the WWW-Authenticate header in the verbose output. If it mentions invalid_scope, you need to update the client config. If it’s invalid_client, check your base64 encoding. I had an issue where a trailing newline in the secret broke the encoding. Double check that.
The 401 usually means the client secret got rotated during the SAML switch. Check the Admin console under Integrations > OAuth Clients. If the client_type is still confidential but the secret is stale, regenerate it. I had to do this last week after forcing SAML. The token endpoint doesn’t give a clear error for expired secrets.