noumen — coding agents are products. This is the library.

Connect to external MCP servers for additional tools, or expose your agent's tools as an MCP server.

noumen supports the Model Context Protocol (MCP) for both consuming external tools and exposing internal tools. This enables interoperability with the growing ecosystem of MCP-compatible tools and clients.

MCP client

Connect to external MCP servers to give your agent access to their tools:

const code = new Code({
  aiProvider,
  virtualFs,
  virtualComputer,
  options: {
    mcpServers: {
      filesystem: {
        command: "npx",
        args: ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"],
      },
      github: {
        command: "npx",
        args: ["-y", "@modelcontextprotocol/server-github"],
        env: { GITHUB_TOKEN: process.env.GITHUB_TOKEN! },
      },
    },
  },
});

await code.init(); // connects to MCP servers and discovers tools

After init(), tools from MCP servers are available to the agent alongside built-in tools.

Server config formats

{
  command: "npx",
  args: ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"],
  env: { SOME_VAR: "value" },
}

Stdio servers are launched as child processes. The agent communicates with them over stdin/stdout using the MCP protocol.

{
  type: "http",
  url: "https://mcp.example.com/sse",
  headers: { Authorization: "Bearer ..." },
}

HTTP servers use the Streamable HTTP transport for remote MCP connections.

Tool naming

MCP tools are named using the convention mcp__serverName__toolName. For example, a read_file tool from a server named filesystem becomes mcp__filesystem__read_file. Special characters in server and tool names are normalized to underscores.

Cleanup

Always close MCP connections when done:

await code.close(); // disconnects all MCP servers

MCP server

Expose your agent's tools (built-in + custom) as an MCP server so external clients can use them:

import { createMcpServer, ToolRegistry } from "noumen";

const registry = new ToolRegistry();

await createMcpServer({
  tools: registry.listTools(),
  toolContext: {
    fs: virtualFs,
    computer: virtualComputer,
    cwd: "/working/dir",
  },
});

This starts a stdio-based MCP server that handles tools/list and tools/call requests. Any MCP client (Claude Desktop, other agents, etc.) can connect and use the tools.

McpClientManager API

For advanced usage, you can use McpClientManager directly:

import { McpClientManager } from "noumen";

const manager = new McpClientManager({
  mcpServers: {
    myServer: { command: "node", args: ["server.js"] },
  },
});

await manager.connect();
const tools = await manager.getTools(); // Tool[] compatible with noumen
await manager.close();