Custom MCP Servers
Add any remote MCP server to a project in Settings → MCP Servers, and Frontend configures it in Claude Code, Codex and OpenCode alongside the built-in servers.
Add a server
Section titled “Add a server”Click Add MCP Server and enter:
- Name — how the server is labelled in the agents, for example
Linear. - URL — the server’s Streamable HTTP endpoint.
- Headers — any headers it needs, usually
Authorization.
New servers are on by default. Use the switch next to a server to turn it off without removing it; the switch works for the built-in servers too.
Keep keys in environment variables
Section titled “Keep keys in environment variables”URLs and header values can reference the project’s environment variables as ${NAME}, so an API key lives in one place instead of being copied into the server’s settings:
| Header | Value |
|---|---|
Authorization | Bearer ${LINEAR_API_KEY} |
If a referenced variable isn’t set, Frontend leaves that server out rather than starting it without its key.
Replacing a built-in server
Section titled “Replacing a built-in server”A server you add for the same service as a built-in one, such as your own GitHub server with a personal access token, replaces the built-in server.