validated-packages.md

Validated Packages

This is the full list of Python packages that have been tested with umo. These packages compile and run successfully in Node.js/TypeScript.

Note: We validate that packages work with basic functionality tests, but we don't maintain full test suite translations from the original Python packages.

Pure Python Packages (componentize-py)

These packages compile to WASM using componentize-py and run without an external runtime.

Web & HTTP

Package	Description
flask	Web microframework
httpx	HTTP client library
jinja2	Template engine

Data & Parsing

Package	Description	Notes
beautifulsoup4	HTML/XML parsing	Import as bs4
simplejson	JSON encoding/decoding
toml	TOML config files
markdown	Markdown to HTML

Database

Package	Description
sqlalchemy	SQL toolkit and ORM

CLI & Display

Package	Description
click	CLI framework
colorama	Terminal colors
tabulate	Table formatting
pygments	Syntax highlighting

Date & Time

Package	Description	Notes
arrow	Date/time handling
python-dateutil	Date utilities	Import as dateutil

Strings & Text

Package	Description
humanize	Human-readable formatting
inflection	String transformations
slugify	URL slug generation
text-unidecode	Unicode to ASCII
chardet	Charset detection
inflect	Pluralization, ordinals

Data Structures

Package	Description
redblacktree	Self-balancing binary search tree
cachetools	Caching utilities (LRU, TTL)

Utilities

Package	Description
attrs	Class decorators
toolz	Functional programming
wrapt	Decorators
pydash	Python utility library (lodash-style)
six	Python 2/3 compatibility
certifi	SSL certificates

Native Extension Packages (Pyodide)

These packages require C/Rust extensions and use the Pyodide runtime instead of componentize-py. They have slightly larger bundle sizes but support the full package functionality.

Package	Description
pandas	Data analysis and manipulation
networkx	Graph/network analysis
numpy	Numerical computing

Known Incompatible Packages

These packages cannot currently be compiled due to fundamental limitations:

Package	Reason
requests	Requires _ssl native module
pydantic	Rust-based core (pydantic_core)
pyyaml	C extension (yaml._yaml)
jsonschema	Rust extension (rpds)
rich	Requires mmap native module
pillow	Case sensitivity issues (PIL vs pil)
aiohttp	Complex async handling

Testing a New Package

To test if a package works:

# Install the package
umo pip-install <package-name>

# Create a test file
echo 'import { someFunction } from "./umo_modules/<package>/index.js";
console.log(someFunction());' > test.mjs

# Run it
node test.mjs

If you find a package that works well, please open a PR to add it to this list!