Guide

How to add an MCP server to Claude Code

The claude mcp add command, in every shape you'll need it

Claude Code is Anthropic's terminal CLI for Claude. Unlike Claude Desktop, it manages MCP servers with a command (claude mcp) rather than a JSON config file.

Add a local (stdio) MCP server

Most published MCP servers ship as npm packages. Add one with:

claude mcp add filesystem \
  -- npx -y @modelcontextprotocol/server-filesystem /path/to/dir

The -- separates the CLI's flags from the command that launches the server. Anything after -- is executed as the server process.

Add a remote (HTTP) MCP server

For a hosted MCP server that speaks Streamable HTTP — like Muninn — use the --transport http flag:

claude mcp add --transport http muninn \
  https://muninn.ferbutech.no/mcp

The first time you call a tool from this server, Claude Code opens an OAuth window to authorize the connection.

Scope: project vs user

By default the server is stored in project scope, so it's only available inside the current repo. To make it available everywhere, add -s user:

claude mcp add -s user muninn \
  --transport http https://muninn.ferbutech.no/mcp

Project-scoped servers are the right choice for repo-specific tools (a database bridge that only makes sense on this codebase). User-scoped is right for anything you always want available, like a notes workspace.

Verify and manage

claude mcp list — show every registered server.
claude mcp get <name> — show one server's config.
claude mcp remove <name> — delete it.

Troubleshooting

"Could not connect to MCP server." Run the server command yourself in a terminal. If it doesn't start on its own, Claude Code can't start it either. For HTTP servers, curl the URL — you should get a JSON-RPC response.
Tools don't appear in a session. Start a new claude session; existing ones don't reload the server list.
OAuth loop for remote servers. Sign in to the underlying service in your default browser first, then retry.