![\"Willow\"](\"https://icons.withwillow.ai/willow/full-logo-green.svg\"){kind=icon}
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\n withwillow.ai\n · \n Documentation\n
\n\n# Willow STDIO Library\n\n`@mcp-s/mcp` is the Willow STDIO library: a local MCP server that speaks stdio\nto your AI client and connects it to your [Willow](https://withwillow.ai/)\nbasecamp.\n\n## What is Willow?\n\n[Willow](https://withwillow.ai/) is the identity and access layer for AI agents\nat work. Instead of every employee wiring their own MCP servers with personal\nAPI keys, Willow gives an organization one control plane: admins connect tools\nonce (1000+ connectors, plus API-to-MCP conversion for internal endpoints),\nscope them by identity with least-privilege permissions, and get a full audit\ntrail of every action an agent takes — with approvals, guardrails, and a kill\nswitch when something goes wrong.\n\n## What this library does\n\nThis package is the client-side half of that: the piece that runs on your\nmachine so your AI client can reach the tools your admin approved.\n\n- **Runs as a stdio MCP server.** Any MCP client that can spawn a process\n (Cursor, Claude Desktop, Claude Code, VS Code, and others) can use it.\n- **Serves your whole Willow basecamp.** Tools, resources and prompts from\n every integration connected in Willow show up in your client, scoped to what\n your identity is allowed to use.\n- **Handles authentication for you.** No API keys to copy around. The first run\n opens a browser sign-in through your organization's identity provider; the\n session is cached in `~/.willow` and refreshed when it expires.\n- **Proxies local MCP servers.** Servers your organization configured to run\n locally are spawned and bridged through the same connection, so a single entry\n in your client config covers everything.\n- **Logs and audits.** Every tool call is reported back to Willow's audit trail,\n and everything the server does is written to a local log file for debugging.\n\n## Installation\n\nAdd Willow to your client's MCP configuration:\n\n```json\n{\n \"mcpServers\": {\n \"Willow\": {\n \"command\": \"npx\",\n \"args\": [\"-y\", \"@mcp-s/mcp\"],\n \"env\": {\n \"ORG\": \"