# ChatGPT Setup

Official source: https://developers.openai.com/apps-sdk/build/auth

ChatGPT connects to Core through a remote MCP connector. This is configured in ChatGPT settings, not by editing local files.

Core MCP server URL:

```text
https://core.gradien.ai/mcp
```

## Setup

1. Open ChatGPT.
2. Open Settings.
3. Go to Apps, Connectors, or Developer Mode, depending on the current ChatGPT UI.
4. Add a custom app, custom connector, or remote MCP connector.
5. Choose Server URL, not Tunnel.
6. Paste `https://core.gradien.ai/mcp`.
7. Choose OAuth for authentication.
8. Approve Core when ChatGPT opens the login or consent screen.

Use Tunnel only for a private/local MCP server such as `localhost`, a dev machine, or a server hidden behind a firewall. Hosted Core uses the public HTTPS Server URL path.

## If Connection Fails

ChatGPT may show a generic error if the OAuth handshake fails. The most common causes are:

- OAuth scopes requested by ChatGPT are not allowed by the provider.
- The ChatGPT redirect URI is not accepted by the authorization server.
- Dynamic Client Registration or the equivalent client registration path is not available.
- The issued access token is rejected by the Core MCP server because the token audience, resource, issuer, expiry, or organization claims do not match.

For production Core, do not switch to No Authentication. Core contains user memory and should be protected by OAuth. No Authentication is only appropriate for a separate disposable smoke-test server.

## Verify

After ChatGPT says the connector is connected, start a fresh chat and check whether Core tools are available. ChatGPT may expose compatibility tools such as search/fetch as well as standard Core MCP tools, depending on current ChatGPT connector support.