MCP Troubleshooting

If you can’t connect to the Criteo MCP server, can’t see the tools you expect, or get odd results from a report, start here.

Don’t paste secrets, API keys, access tokens or Authorization headers into tickets, screenshots or chat. An MCP URL with ?api-key=... in it is a credential too: anyone who has the URL has your access.

Before you start

Use the MCP URL Criteo gave you, including the flavor in the path if there is one.
Make sure your organization is approved for MCP access. If Criteo supplied your credentials, it already is.
If you use OAuth, register the redirect URIs your client asks for on your application. See Access Flows.

Common problems

What you see	Why	What to do
`401` “Invalid credentials: a valid Authorization or x-api-key header, or an api-key query parameter, is required.”	The server received no usable credentials.	Check your auth method, and that your client sends credentials with every request.
`401` “The provided token is invalid, expired or revoked.”	Your access token has expired or been revoked.	Disconnect, reconnect and consent again.
`401` “Organization with id: … is not allowed to access the MCP server.”	Your organization isn’t approved for MCP access.	Ask your Criteo representative to approve your API organization.
`403` “The access token is missing scopes to access MCP Flavor ’…’”	Your application doesn’t have the scopes this flavor needs.	Create a new application with the right scopes. You can’t add scopes to an existing one.
`404` “MCP Flavor ’…’ not found”	The flavor in your MCP URL is wrong.	Use the exact URL Criteo gave you.
Redirect URI error	The callback URL isn’t registered on your application, or doesn’t match exactly.	Register the redirect URI your client shows, then disconnect and reconnect.
Connected, but tools are missing	Your client hasn’t refreshed its tool list, or your application lacks the scopes for the flavor.	Reconnect. If the tools still don’t show, create a new application with the right scopes.
A report returns an ID but no data	Reports run asynchronously.	Ask your client to check the report status and fetch the output.

If you use Claude, register both of these callback URIs:

https://claude.ai/api/mcp/auth_callback
https://claude.com/api/mcp/auth_callback

Dynamic Client Registration isn’t supported yet, so you need to register your client yourself.

Reports

Report and catalog exports don’t return results straight away. The client starts the export, checks its status until it finishes, then downloads the output. The Tool Reference lists the tools for each step.

Still stuck?

Contact your Criteo representative. Include the MCP URL (with secrets removed), your organization and application IDs, the exact error message, and the report ID and time if a report is involved.

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Before you start

Common problems

Reports

Still stuck?

​Before you start

​Common problems

​Reports

​Still stuck?

Before you start

Common problems

Reports

Still stuck?