Monaco Editor Assets

A Python package that provides easy access to Monaco Editor assets. Assets are automatically downloaded on first use, eliminating the need to bundle large files with the package. Optionally, the assets can be served by a local webserver on a custom port (MonacoServer); the required fastapi and uvicorn packages are installed together with monaco-assets.

Installation

python3 -m pip install monaco-assets
# or
uv pip install monaco-assets

Quick Start

import monaco_assets
server = monaco_assets.MonacoServer(port=8000)

Now, you can use http://localhost:8000/min/vs/loader.js in a webbrowser to see, e.g., loader.js. Please note that there are no directory listings, one has to directly address the file(s).

Cache Management

import monaco_assets

# Clear cache to free space before uninstalling the package
monaco_assets.clear_cache()

# Check whether the assets are already cached (no download needed)
if monaco_assets.has_cached_assets():
    ...
else:
    # a download will take place; e.g. show a progress indicator
    assets_path = monaco_assets.get_path(progress_callback=show_progress)

Download Progress

On a cold cache, get_path() downloads the Monaco Editor assets (~100 MB extracted). You can report the download progress in real time by passing a progress_callback that receives (bytes_downloaded, total_bytes):

import monaco_assets


def show_progress(done: int, total: int | None) -> None:
    if total is not None:
        print(f"\r{done / total:.0%} of {total / 2**20:.1f} MiB", end="", flush=True)
    else:
        print(f"\r{done / 2**20:.1f} MiB", end="", flush=True)


assets_path = monaco_assets.get_path(progress_callback=show_progress)

Notes:

• The callback is only invoked if a download actually takes place; on a warm cache get_path() returns immediately without calling it. If you build progress UI around the call, check has_cached_assets() first to avoid showing it unnecessarily.
• total_bytes is None if the server does not send a Content-Length header. The first chunk is always reported; further calls are throttled to at most one per 0.5 seconds, plus a final call when the download completes.
• If you call get_path() from a background thread yourself, make the callback thread-safe accordingly.

Cache Locations

Assets are cached in platform-appropriate directories using the platformdirs library

How It Works

1. First Use: When get_path() is called for the first time, the package:

   • Downloads Monaco Editor from npmjs.org
   • Verifies the download integrity with SHA1 hash
   • Extracts assets to the user cache directory
   • Returns the path to the assets

2. Subsequent Uses: The package checks the cache and returns the existing assets path immediately.

Download Issues

If asset download fails:

1. Check internet connectivity
2. Verify firewall settings allow access to registry.npmjs.org
3. Check disk space in cache directory

Cache Issues

Clear and re-download if corrupted.

monaco_assets.clear_cache()
assets_path = monaco_assets.get_path()

Version Correspondence

Version correspondence will be ensured after initial bugfixes.

Requirements

• Python 3.10+
• Internet connection (only for initial asset download)
• ~100MB disk space for Monaco Editor assets

License

MIT License - see LICENSE file for details.

Monaco Editor is licensed under the MIT License by Microsoft Corporation.