403 forbidden when calling an AI skill form a MCP client (Postman or MS Copilot)

[arielgritti]

Hi community,

I'm running a 403 forbidden error when trying to use an AI skill (incident summarization) published by a ServiceNow MCP server.

Scenario:
OAuth Client Credentials (with an integration user with ITIL role)
AI Skill (OOTB) requires ITIL role

Token is generated OK
I'm able to "connect" from both MCP clients (Postman and MS Copilot)
The "tool" is available

When trying to execute, 403 forbidden is the error.

Any idea? Any help is welcome.

Thanks,
Ariel

[Tanushree Maiti]

Probable cause could  be:

1. If your ServiceNow instance has IP filtering, and your client (Postman/Copilot) is running from an un-whitelisted IP address, it will return a 403.

2.   Impersonate the integration user and try to run the REST query directly via the ServiceNow REST API Explorer to identify which table ACL is denying access.

   - Give the proper role to Integration user