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ToolsConnectors

Custom MCP servers

Bring an internal or niche MCP server in as a Connector

Register a remote MCP server as a Connector when the catalog doesn’t cover a system you need. Its tools then reach employees through Tool Packs and Groups like any other Connector. You operate the server; Merge proxies calls to it.

Requirements

  • A public HTTPS URL that completes an MCP initialize handshake. Merge supports protocol revisions 2025-03-26 and 2024-11-05.
  • No auth, or one static bearer token or API key shared by all employees. Per-employee OAuth 2.0 with PKCE is available on request from Merge.
  • Local servers (such as npx <package>) are not supported

Register a server

  1. In Connectors, click Add new
  2. Enter a Name (unique, and not the name of any Connector Merge ships), the Remote MCP server address, and the Authorization token
  3. Save. Merge discovers the server’s tools.

If discovery fails, the Connector is created with zero tools and an error. Check that the endpoint is reachable, the token format is right, and the server completes initialize.

Then add it to a Tool Pack. It reaches nobody until you do.

OAuth servers start with no tools

A server that uses OAuth lists its tools only to someone signed in, so its Connector starts empty. To fill it in, open the Connector and either:

  • Click Fetch tools and sign in yourself
  • Click Get setup link and send the link to whoever should sign in. The link works for 24 hours, and anyone who opens it can complete it

The tools also fill in the first time any employee signs in to the Connector. Once a Connector has tools, a later sign-in doesn’t replace them.

Manage a server

  • Tools: Merge refreshes the tool list periodically. Click Resync to refresh now. New tools reach nobody until added to a Tool Pack.
  • Token rotation: replace the token under Application Credentials when you rotate it on your server. Calls fail while Merge holds the old one.
  • Delete: removes the Connector from every Tool Pack, and employees lose its tools immediately. Check its Tool Packs tab first.