# Troubleshooting Tariff Code Compliance connections

Use this guide when Tariff Code Compliance will not connect, open sign-in, or complete a request from Claude, ChatGPT, or another MCP client.

## Start here

1. Confirm that your client is using the exact production MCP endpoint:

```text
https://api.prod.tariffcodecompliance.com/tariff-code-compliance/v1/mcp
```

2. Open your existing Tariff Code Compliance connection and choose **Connect** or **Reconnect** first. Avoid duplicate connections. If `invalid_client` persists after reconnecting, confirm which connection is failing before removing and recreating only that custom connection.
3. Retry in a normal browser window and allow pop-ups for your client and Auth0 so sign-in and consent can finish.
4. Never paste an access token, password, or other credential into a chat or support request.

## Claude

- **You cannot find connector settings:** from Claude's home screen, choose **Customize**, then **Connectors**.
- **The connector is unavailable in a Team or Enterprise workspace:** ask an Owner or Primary Owner to add or enable it for the workspace.
- **A Free account cannot add another custom connector:** Anthropic currently limits Free accounts to one custom connector. Remove the unused connector or use the official Tariff Code Compliance connector.

Return to [Tariff Code Compliance for Claude](/docs/claude) for the illustrated setup paths.

## ChatGPT

- **Developer mode or app creation is unavailable:** look under **Settings → Security and login → Developer mode**, then **Plugins → Add (+) → Create MCP App**. Some interfaces open **New Plugin** directly or say **Create app**. Check your account and workspace policy against OpenAI's [connection guide](https://developers.openai.com/plugins/deploy/connect-chatgpt).
- **The app does not open sign-in:** confirm the endpoint above, allow the authorization window, then use **Connect** or **Reconnect** on the existing connection before recreating it.
- **The wrong app is selected:** distinguish the public Tariff Code Compliance plugin from your developer-mode connection. Give the latter a unique name such as `TCC MCP Prod`, then explicitly select it in a new conversation.
- **Sign-in works but research fails:** request `get_account_status` to check verification, access, balance, and recharge state. It remains available at zero balance. Follow the returned account or billing link yourself; do not put credentials in chat or ask the agent to authorize a payment.
- **A new tool is missing:** `tools/list` describes the connected server catalog, not guaranteed published-plugin visibility. Refresh a developer-mode connection and start a new chat. Published plugins use OpenAI review for tool updates; updated imported skills require a new version. Do not delete a working public installation merely because source documentation mentions a newer tool.
- **A search returns nothing:** preserve the selected returned tariff version and inspect coverage and filters. An empty result is not proof that no relevant law or classification exists. See the [HTS search reference](/docs/mcp/tools).

Return to [Tariff Code Compliance for ChatGPT](/docs/chatgpt) for the illustrated setup path.

## MCP clients and cURL

- **OAuth does not open:** confirm that the endpoint is exact and that the client supports remote Streamable HTTP OAuth connectors.
- **A request returns HTTP 400:** confirm that `Mcp-Method` matches the JSON-RPC method and that `Mcp-Name` matches `params.name` for `tools/call`.
- **A request returns HTTP 401 or 403:** reconnect through OAuth instead of reusing an expired token, and confirm that the grant includes `tcc.knowledge_graph.read` and the current Tariff Code Compliance Explorer MCP entitlement.

Return to [Tariff Code Compliance Explorer with MCP](/docs/mcp) for endpoint, protocol, discovery, and cURL details.

## Still need help

If your issue is not described here, [contact support](/contact?intent=SUPPORT). Include the client you are using, the step that failed, and the visible error message. Do not include passwords, tokens, or other credentials.