line-desktop-mcp

Unofficial community project. Not affiliated with, endorsed by, or supported by LINE Corporation or LY Corporation. Uses your own logged-in account through the LINE Chrome Extension. Read tools are side-effect free; clear_session is the only destructive tool and needs explicit confirmation.

FastMCP server for LINE Desktop automation. Wraps line-ext-msg>=1.2 (LINE Chrome Extension reader) as MCP tools.

LINE tools

Read tools are side-effect free (no files written, no media downloaded). Every result uses an ok/data/error envelope; failures carry a next field telling the AI what to ask the user to do. Session tools live in their own domain: probe_session is safe to call any time, clear_session wipes the login and always needs a fresh QR scan afterwards.

First run opens a separate Chrome profile: call line_status, log in with QR/email in the window that opens, then call wait_login. Chrome runs headless by default and pops a visible window only for the QR scan; the login normally survives restarts. Only clear_session forces a fresh login every time. Room ref accepts index, data-mid, or name substring (prefer data-mid or name: index shifts when rooms reorder). Dates use YYYY-MM-DD. search_messages never scans all rooms: pass candidates from list_rooms first. Message reads backfill by scrolling up to limit (bounded ~8s); pass scroll=false for fast on-screen-only reads. When login looks flaky, call probe_session first; call clear_session with confirm=true only after the user agrees to log out. wait_login accepts up to 600 seconds and always covers it without cutting off early. After a QR login it settles briefly and proves headless reuse inside the same call, so ok:true means later tools can call right away with no manual waiting. search_messages skips refs that match no room (returned as RoomNotFound entries) instead of failing the whole call. Image bubbles are text-only by default; pass include_media=true to get_messages when the AI needs to see pictures.

Tests

uv run python -m unittest discover -s tests -v

Browser-free unit tests only (room resolving, envelopes, login wait, session gate, CLI defaults). No Chrome needed.

Run (dev)

uv sync
uv run line-desktop-mcp --help
uv run line-desktop-mcp

Run with HTTP transport for remote access:

uv run line-desktop-mcp --transport http --port 8000

Run via FastMCP CLI:

uv run fastmcp run src/line_desktop_mcp/server.py:mcp

Use without cloning (after PyPI release)

uvx line-desktop-mcp --help
pipx install line-desktop-mcp
pipx run line-desktop-mcp --help

Test a local wheel before release:

uv build
uvx --from ./dist/line_desktop_mcp-1.1.0-py3-none-any.whl line-desktop-mcp --help

Claude Desktop config

{
  "mcpServers": {
    "line-desktop": {
      "command": "uvx",
      "args": ["line-desktop-mcp"]
    }
  }
}

For a local checkout use uv:

{
  "mcpServers": {
    "line-desktop": {
      "command": "uv",
      "args": ["--directory", "D:/path/to/line-desktop-mcp", "run", "line-desktop-mcp"]
    }
  }
}

Structure

src/line_desktop_mcp/
  server.py        # FastMCP("line-desktop-mcp") wiring only
  cli.py           # argparse + mcp.run(), installed as `line-desktop-mcp`
  tools/line_msg.py # LINE tools (status, login wait, rooms, messages, search)
  tools/session.py  # Session tools (probe_session read-only, clear_session destructive)

Add a new tool domain by creating tools/<domain>.py with a register_<domain>_tools(mcp) function, then calling it from server.py.

Publish

uv build
uv publish

Requires requires-python = ">=3.10" and the line-desktop-mcp console script defined in pyproject.toml.