Guide · Clients

Wire ChatGPT to Munin.

ChatGPT’s custom MCP apps (previously called Connectors) let you point it at any remote MCP server. Add Munin and the assistant can search the KB, look up contacts, read deals, draft replies, and publish CMS entries — gated by the scopes on the key you mint.

Availability

Custom MCP apps require Developer Mode, which ships on ChatGPT Plus, Pro, Business, Enterprise, and Edu. Plus and Pro accounts get read/fetch tools only; write-capable tools require Business, Enterprise, or Edu.

1 · Mint an API key

From the dashboard, go to Settings → API keys and create one. Scope it to what ChatGPT should be allowed to do. The token starts with mn_admin_ and is shown once.

2 · Enable Developer Mode

Open Settings → Connectors → Advanced (workspace admins use Workspace Settings → Permissions & Roles) and turn Developer Mode on. The option to add a custom MCP app only appears after this is enabled.

3 · Add the custom app

Back in Settings → Connectors, click Create. Fill in:

Name: Munin (or anything you want to see in the tool picker).
Description: Optional. Helps your team disambiguate if you operate multiple Munin orgs.
MCP server URL: http://localhost:3001/mcp
Authentication: No authentication is the default for the form, but Munin requires a bearer token. Pick Custom and add an Authorization header with value Bearer mn_admin_….
I trust this application: ChatGPT requires explicit confirmation before letting you save a custom app. Tick the box once you’ve verified the URL is correct.

Save. ChatGPT runs the MCP handshake immediately and lists the tools it discovered. If the handshake fails it surfaces the error verbatim — usually a 401 (wrong token), a 404 (wrong path — it’s /mcp, not /v1/mcp), or a TLS issue.

4 · Enable per conversation

Adding the app doesn’t auto-attach it to every chat. In the composer, open the tools menu and toggle Muninon. ChatGPT will then call Munin tools when it decides they’re relevant — or you can name a tool directly in the prompt.

5 · Tighten scope

Issue a separate Munin key per ChatGPT user or workspace, with the smallest scope that gets the job done. Revocations take effect on the next request — no need to remove the app on the ChatGPT side.