Arc Control (macOS) MCP Server

What the code does

We read the source, 5 d ago · rules 995398eba69f

What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.

    const child = execFile(

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Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

claude mcp add arc-control-mcp -- npx -y arc-control-mcp

{
  "mcpServers": {
    "arc-control-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "arc-control-mcp"
      ]
    }
  }
}

[mcp_servers.arc-control-mcp]
command = "npx"
args = ["-y", "arc-control-mcp"]

{
  "mcpServers": {
    "arc-control-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "arc-control-mcp"
      ]
    }
  }
}

{
  "servers": {
    "arc-control-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "arc-control-mcp"
      ]
    }
  }
}

Optional settings from the registry entry, left out of the block above: ARC_MCP_LABEL (Names this agent's tab ownership. Two agents with different labels never see each other's owned tabs. Defaults to "default"), ARC_MCP_SPACE (With ARC_MCP_WINDOW=space, the Arc space new tabs open into, when a space with that name exists. Arc will not let a script create a space, so make it by hand. Defaults to "Agent"), ARC_MCP_STATE_DIR (Directory where per-session tab ownership is recorded, so a restarted agent can clean up the tabs its previous run left behind. Defaults to ~/Library/Application Support/arc-control-mcp), ARC_MCP_WINDOW ("dedicated" keeps agent tabs in one separate agent window, never the user's own. "space" puts them in the Agent space of the user's window. Defaults to "dedicated"), ARC_MCP_WINDOW_PLACEMENT (Where the agent window goes once, at creation: "auto" (largest non-main display, else where Arc puts it), "second-display", "minimized" (experimental) or "none". Needs Accessibility. Defaults to "auto"), ARC_MCP_IDLE_MS (How many milliseconds the user must have been idle before the server does anything visible. 0 turns the activity gate off. Defaults to 1500), ARC_MCP_IDLE_WAIT_MS (How many milliseconds to wait for that pause before failing with userActive true. Defaults to 15000), ARC_MCP_ARC_DATA_DIR (Directory the local data tools (sidebar_tree, find_stale_tabs, search_archive, search_history) read Arc's files from. Defaults to ~/Library/Application Support/Arc), ARC_MCP_ALLOW_HISTORY (Set to 1 to let search_history run. Off by default, and any other value leaves it off), ARC_MCP_CDP (Set to 0 to disable the DevTools engine (trusted input, screenshots, console and network capture). On by default, and inert until Arc is launched with --remote-debugging-port), ARC_MCP_CDP_PORT (The DevTools port to probe on 127.0.0.1. The host is fixed. Defaults to 9222), ARC_MCP_ALLOWED_ORIGINS (Guardrail. Comma list of origins the agent may touch (host, *.host, scheme://host[:port], file://, about:). Anything not listed is refused. Unset means no allow list), ARC_MCP_BLOCKED_ORIGINS (Guardrail. Comma list of origins the agent may not touch. Wins over the allow list. Unset means no block list), ARC_MCP_BLOCK_READS (Set to 1 to apply the origin lists to read tools as well as changing ones. Off by default), ARC_MCP_READ_ONLY (Set to 1 to expose only the read-only tools. Off by default), ARC_MCP_AUDIT_LOG (Path of a file that gets one JSON line per changing call (time, tool, tab, origin, ok, error), never typed values or script code. Unset means no audit log).