MCP Setup

Help users configure MCP servers so external tools (e.g. Linear, GitHub, Notion) become available in conversations.

CLI Commands

All commands use assistant mcp. Run list, add, and remove via the bash tool — they just read/write config and don't need host access. Run auth via host_bash because it binds a localhost OAuth callback server that the user's host browser must redirect back to.

List servers

assistant mcp list

Shows all configured servers with connection status, transport type, and URL.

Add a server

assistant mcp add <name> -t <transport-type> -u <url> [-r <risk>] [--disabled]

• <name> - unique identifier (e.g. linear, github)
• -t - transport type: stdio, sse, or streamable-http
• -u - server URL (required for sse/streamable-http)
• -c - command (required for stdio), -a for args
• -r - risk level: low, medium, or high (default: high)

Examples:

assistant mcp add linear -t streamable-http -u https://mcp.linear.app/mcp
assistant mcp add context7 -t streamable-http -u https://mcp.context7.com/mcp -r low
assistant mcp add local-db -t stdio -c npx -a -y @my/mcp-server

Authenticate (OAuth)

assistant mcp auth <name>

Opens the user's browser for OAuth authorization. Only works for sse/streamable-http servers that require authentication. After the user completes login in the browser, tokens are saved automatically.

Use this when:

• A server shows ! Needs authentication in assistant mcp list
• An MCP tool call fails with an auth/token error
• Setting up a new OAuth-protected server for the first time

Remove a server

assistant mcp remove <name>

Removes the server config and cleans up any stored OAuth credentials.

After Changes

After adding, removing, or authenticating a server, the user must quit and relaunch the Vellum app for changes to take effect. The app runs its own assistant process - assistant daemon restart only restarts the CLI assistant, which is a separate process.

Tell the user: "Please quit and relaunch the Vellum app, then start a new conversation."

When to Use

• User asks to connect/set up an external service via MCP
• User asks "what MCP servers do I have?"
• An MCP tool returns an auth error - offer to run assistant mcp auth <name>
• User wants to remove an MCP integration