Connect Tariff Code Compliance to ChatGPT with a Custom App

You do not need to leave ChatGPT to use Tariff Code Compliance for tariff research. The public Tariff Code Compliance plugin is now the recommended customer path. This article preserves the developer-mode custom app method for teams that need to validate the same hosted, read-only MCP service directly.

For both installation methods, use the canonical ChatGPT guide. For the public release, current listing screenshots, and a complete classification example, read Tariff Code Compliance for ChatGPT Is Live.

1. Enable Developer mode

1. Open ChatGPT on the web and open your profile menu.
2. Choose Settings, then Plugins.
3. Follow the Developer mode link. ChatGPT opens Security and login at the Developer mode setting.
4. Turn on Developer mode and review the risk notice.

Developer mode allows unverified MCP servers, so connect only services you trust. OpenAI keeps its current eligibility, safety, and platform notes in the official Developer mode and MCP apps guide.

2. Create the Tariff Code Compliance app connection

ChatGPT now uses a shared Plugins directory. The Create app control opens a New Plugin form for the underlying custom app. Older instructions may call the same kind of MCP integration a custom connector.

1. Open Plugins in ChatGPT and choose Create app.
2. In the New Plugin form, use Tariff Code Compliance as the name.
3. Keep Server URL selected for the connection and OAuth selected for authentication.
4. Paste this exact value into MCP Server URL:

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

5. Review ChatGPT's unverified-server warning, confirm that you want to continue, and choose Create.

3. Create your Tariff Code Compliance Explorer account and approve access

ChatGPT opens the normal Tariff Code Compliance authorization window. If you are new to Tariff Code Compliance, create your Tariff Code Compliance Explorer account; that is the default path. If you already have an account, sign in instead.

Review the requested read access to the Tariff Code Compliance Explorer knowledge graph, then approve the connection. Tariff Code Compliance Explorer tools accessed through MCP read tariff evidence; they do not write to your catalog. Never paste a Tariff Code Compliance Explorer password, access token, authorization code, or other credential into ChatGPT or the plugin form. Authentication belongs only in the Tariff Code Compliance Explorer sign-up or sign-in window.

4. Verify the connection

Open a new chat, add Tariff Code Compliance from the Plugins control, and send this small connection check:

Use Tariff Code Compliance to list the tariff systems available right now. Include each system's exact active version.

A successful result names the tariff systems returned at runtime and their exact versions. That proves ChatGPT can reach Tariff Code Compliance without turning this setup check into a product classification.

What to try next

The next useful step is to see how Tariff Code Compliance evidence changes a real tariff-research conversation:

• Start with the flannel-shirt classification walkthrough for a complete example built from a thin ecommerce listing.
• Follow how Claude researches a U.S. HTS code for a cotton T-shirt to see the facts, hierarchy, alternatives, and uncertainty in a complete example.
• Read what Claude can and cannot do with HS codes for the workflows where current Tariff Code Compliance evidence helps and the boundaries that still require judgment.

Those articles use Claude screenshots, but the Tariff Code Compliance Explorer with MCP research approach is the same. They do not depict the ChatGPT interface.

Deeper documentation

• Review the illustrated Tariff Code Compliance for ChatGPT guide.
• Read Tariff Code Compliance Explorer with MCP for the current endpoint, OAuth, and protocol reference.
• Use the MCP tools reference and connection troubleshooting guide for detailed behavior and errors.