Hostbeam MCP server

Hostbeam sends a screenshot from your Mac to a server over SSH and puts the remote path on your clipboard, so you can paste it to a coding agent running there.

This MCP server runs on that server, next to the agent. The agent can ask for the screenshot you just beamed and read it, without you pasting the path.

Install

On the server your agent runs on, not on your Mac. Node 18 or later.

For Claude Code:

claude mcp add -s user hostbeam -- npx -y @hostbeam/mcp

-s user makes it available in every project on that server.

For Codex:

codex mcp add hostbeam -- npx -y @hostbeam/mcp

For other MCP clients, in their JSON config:

{
  "mcpServers": {
    "hostbeam": {
      "command": "npx",
      "args": ["-y", "@hostbeam/mcp"]
    }
  }
}

If the server can't reach npm, copy hostbeam-mcp.mjs to it and run that instead. It has no dependencies.

claude mcp add -s user hostbeam -- node /path/to/hostbeam-mcp.mjs

Hostbeam beams to /tmp/hostbeam unless you changed the folder for that host. If you did, give the server the same folder: -e HOSTBEAM_DIR=/your/folder for Claude Code, --env HOSTBEAM_DIR=/your/folder for Codex, or "env": { "HOSTBEAM_DIR": "/your/folder" } in JSON.

Tools

• latest_screenshot returns the most recent beam as images, with how long ago it arrived. If you beamed several files at once, it returns all of them, up to six, and names the rest.
• list_screenshots lists recent beams with file names, sizes and times. No image data.
• read_screenshot returns one file by name.

What it reads

Only files Hostbeam delivered: names starting with hostbeam- with an image extension, in that one folder. It doesn't look in subfolders, and it refuses a name with a path in it. It never writes, moves or deletes anything.

It skips symlinks, and it won't read a folder that belongs to another user or that any user can write to, because a file there may not be one you beamed.

JPEG, PNG, GIF and WebP come back as images, up to 3.75 MB each. Other formats and larger files come back as a path instead: models only accept those four formats, and model APIs refuse bigger images. When a beam holds several files, latest_screenshot includes images up to 7.5 MB in total and names the rest.

Check it by hand

It speaks newline-delimited JSON-RPC on stdin and stdout:

printf '%s\n' \
  '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' \
  '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"list_screenshots"}}' \
  | npx -y @hostbeam/mcp

License

MIT