How We Got Local MCP Servers Working in Claude Cowork (The Missing Guide)

TL;DR: Everyone says "MCP doesn't work in Cowork." We solved it using supergateway + pm2. It worked on the first try. Here's the full setup. The Problem Claude Code's Cowork mode runs inside a sandboxed VM. This means local stdio MCP servers — which run as child processes on your machine — simply can't connect. The VM has no access to your local processes. The community response has been universal: "MCP is not supported in Cowork." But that's not entirely true. The Solution: Two Layers We discovered that Cowork actually supports MCP through two different mechanisms — and by combining them, we got 18+ MCP servers working reliably in production. Layer 1: Claude Desktop SDK Bridge (Built-in, Undocumented) What most people don't realize: if you configure MCP servers in your claude_desktop_config.json , Claude Desktop automatically bridges them into the Cowork VM via its SDK layer. // claude_desktop_config.json (on your local machine) { "mcpServers" : { "outlook-mcp" : { "command" : "node"