ChatGPT

ChatGPT Desktop & Web

Entry point

• ChatGPT web (chatgpt.com): Open Plugins from the left sidebar, then click '+' New Plugin.
• ChatGPT Desktop: Does not support creation/configuration of MCP plugins. Use Web interface to create and configure Baselayer plugin and it will be reflected and usable in the Desktop.

Add Baselayer as a connector

1. Open Plugins from the left sidebar, then click '+' New Plugin.

   Note: Don't use the separate MCPs tab's "Connect to a custom MCP" quick-add form — that form only supports Bearer-token or header authentication, has no OAuth fields at all, and cannot be used for this integration.

2. Fill in the form:

   Field	Value
   Name	Baselayer
   Description	Search and verify businesses with Baselayer
   Connection	Server URL
   	https://api.baselayer.com/mcp
   Authentication	OAuth

3. Expand Advanced OAuth settings.

4. Under Registration method, select User-Defined OAuth Client.

5. Enter the following values

   Field	Value
   OAuth Client ID	chatgpt-connector
   OAuth Client Secret	(leave empty)
   Token endpoint auth method	none

6. Leave the remaining advanced OAuth Settings unchanged

7. Check I understand and want to continue

8. Click Create.

9. A popup will appear. Click Sign in with Baselayer

10. Sign in with your Baselayer credentials. If you do not have an account, use the Sign up link on that page.

11. Allow on the consent screen ("Search and verify businesses with Baselayer on your behalf"). The browser returns you to the Baselayer plugin's detail page, showing it connected with its tools listed.

Click Try in chat to start a new conversation with Baselayer enabled and try it with one of the Example Prompts below!

Remove Baselayer as a connector

To sign out without deleting your configuration, open Plugins, find Baselayer, click the '⋯' menu, and choose Disconnect. This revokes your session but keeps the connector's configuration.

To remove the connector entirely — required before you can change the Registration method or other stored OAuth settings — use the same '⋯' menu and choose Manage instead. This opens the plugin's settings page. Click the '⋯' menu there and choose Delete.

Codex CLI

Codex CLI is not supported yet. It registers with the identity provider using a mechanism Baselayer's provider does not accept today; support arrives with an upstream fix and needs no change on your side.

Until then, use Claude Code for terminal workflows.

Example prompts

• "Verify Acme Holdings LLC at 500 Main St, Austin TX 78701 and tell me whether the EIN 12-3456789 matches."
• "Run a full KYB on Acme Holdings LLC with website analysis and industry classification, then summarize the risk signals."
• "Screen Jane Doe against OFAC and PEP."
• "Check for UCC filings, tax liens, litigation, and bankruptcies against Acme Holdings LLC in Texas."
• "Find Ray's Famous Pizza's website and social profiles and summarize what customers say in reviews."

ChatGPT chooses the right tool from the tool list. Tools that start paid work, such as a new search, ask for your confirmation before running unless you approve them for the conversation; read tools run without a prompt.

Organization and application

ChatGPT does not let you attach headers to a connector, so tool calls always run in your default organization's production application. If you belong to several organizations, or want sandbox data, use Claude Code or the REST API instead.

Troubleshooting

"Your admin has not enabled developer mode," with the Developer mode toggle greyed out. Your ChatGPT workspace is on Business, Enterprise, or Edu, and a workspace admin has not turned on Developer mode for members yet — you cannot enable this yourself. Ask your workspace admin to turn it on, then return to Settings → Security and login.

"Client not found" or a login error after entering the URL. The OAuth Client ID was mistyped, or something was entered in the Client Secret field — that field must stay empty. Re-enter Client ID chatgpt-connector exactly and leave Client Secret blank.

"We are sorry... Client Metadata fetch failed" on the Baselayer sign-in page. Go back and double check steps 3–4 (Connection URL and Authentication method) are correct, then open the plugin's Advanced OAuth settings and set Registration method to User-Defined OAuth Client with Client ID chatgpt-connector, secret blank, and Token endpoint auth method none, as described above.

Sign-in completes but the connector shows an error. Your account must belong to an organization with at least one enabled application. Sign in to the Console to confirm, then reconnect.

A tool returns "Caller lacks the required permission". Your role does not include that product. The permissions table names the permission each tool needs; an organization admin can grant it in the Console under Members.

For anything else, email [email protected].