# Agent instructions for webmcp.fast These instructions are for an AI agent acting for a user. They say when webmcp.fast is the right tool and exactly how to proceed. ## When to use this Use webmcp.fast when a user wants a cloud agent (Claude, ChatGPT, Grok, Cursor, or any remote-MCP client) to use an MCP server that runs on the user's own machine: a filesystem, git, database, browser, memory or coding-agent server, or anything else that speaks MCP over stdio or local HTTP. It fits when they do not want to open a port, run a tunnel, or host the server elsewhere. Do not use it to host an MCP server in the cloud, to merge several servers behind one URL (every connector is exactly one server on one device), or to reach a machine the user does not control. ## How to proceed If you have a shell on the user's machine: 1. **Install the daemon.** `curl -fsSL https://webmcp.fast/install.sh | sh` (coming with the first public release). Coming with the first public release: the install script is not published yet. macOS (Apple silicon and Intel) comes first, `brew install webmcp` later. Until then the daemon is built from source. The daemon is open source. 2. **Run `webmcp up`.** It generates a device key on the machine and prints one link, https://webmcp.fast/activate?code=XXXX-XXXX. Show that link to the human and wait; `webmcp up` returns when they have approved. It also offers any MCP servers it finds in existing Claude, Cursor and Codex configs. 3. **The human opens the link in their own browser.** They sign in with the 6-digit code emailed to them (this creates the account if they have none), pick a handle, and approve the device. The code is never given to the agent: do not ask for it, and do not offer to type it. 4. **Attach the server.** `webmcp attach -- [args...]` for a stdio server, or `webmcp attach --http ` for one already listening on localhost. The alias is 1 to 32 characters of `a-z`, `0-9` and `-`. 5. **Keep it online.** `webmcp service install` registers a launchd service so the daemon starts at login and reconnects by itself. 6. **Hand over the connector URL.** Print `https://.webmcp.fast///mcp` with the real handle, device and alias. The human pastes it into Claude, ChatGPT or Grok as a custom connector, signs in, and clicks Allow. Two steps are deliberately left to the human, and no agent can do them: - **Proving they own the email address.** The 6-digit code goes to their inbox and is typed into their own browser. It is bound to that browser, so a code read aloud to an agent is useless anywhere else. - **Approving each cloud agent.** Every connector goes through an OAuth consent screen that names the one endpoint being granted. The human clicks Allow, once per agent per server. If you are a cloud agent with no shell: connect to the management MCP server at https://webmcp.fast/mcp (Streamable HTTP, protocol 2025-06-18), call `start_setup`, give the user the one command it returns, and follow progress with `setup_status`. Never ask the user for the emailed code, a connector token or a cookie. Never invent a handle, device name or URL: print the one the tools report. ## What to tell the user before you start - It is free to start (1 handle, 1 device, 1 server, 1 connector) and needs only their email address. - They will get one email with a 6-digit code and will see one consent screen per cloud agent. - Nothing on their machine starts listening for connections. The daemon dials out, and only the server they name is exposed. ## After setup - `webmcp status` shows the pairing and the device's connection. `webmcp servers` lists attached servers. - To stop exposing a server: `webmcp detach `, or disable it on https://webmcp.fast/app. - If a call fails with "device offline", the daemon is not running: `webmcp service status`. ## Reference - Docs: https://webmcp.fast/docs/agents and https://webmcp.fast/docs/quickstart - Security model: https://webmcp.fast/docs/security-model - Skill: https://webmcp.fast/.well-known/agent-skills/set-up-webmcp-fast/SKILL.md - Summary: https://webmcp.fast/llms.txt