Document · Krew · 7 min read

Using MCP Servers with Kaptain

Kaptain can connect to external MCP servers and make their tools available through the Krew tool system.

What MCP adds

MCP servers expose external tools. When connected and enabled, those tools can become part of the Kaptain Krew tool set. Kaptain routes calls through its dispatcher rather than asking a model to operate the external service directly.

Before connecting

Kaptain does not install every MCP server runtime for you. Install whatever the chosen MCP server requires first: Docker, Node/npx, Python, Go, a local binary, network access, API credentials, or service-specific setup.

Security note: Only connect MCP servers you understand and trust. A tool can expose powerful actions depending on the server.

Connection flow

  1. Open Krew Tools.
  2. Select Connect MCP Server.
  3. Choose stdio for a local command or HTTP/SSE for a running endpoint.
  4. Enter the command or endpoint.
  5. Add environment variables or headers if the server requires credentials.
  6. Connect and let Kaptain discover tool names.
  7. Enable the server and use Kaptain normally.

Will Kaptain call MCP tools automatically?

When the MCP server is connected, enabled, and discovered, its tools can be included in the Krew tool set for tool-capable runs. If the active model selects one of those tools, Kaptain calls the MCP server.

You can also ask explicitly, for example: Use the GitHub MCP tool to list open pull requests.

Agent tool scope

Team members may have scoped tool access. If an agent has a restricted tool list, allow that Krew tool in the team-member edit panel before expecting the agent to use it. If no per-member scope is set, globally enabled Krew tools are available.

Examples

Generic stdio server:

npx -y some-mcp-server

Generic HTTP/SSE endpoint:

https://example.com/mcp

Headers can be used when the server requires authentication:

Authorization=Bearer ...