Installation¶

p2w is a Python package that produces WebAssembly text. Running what it produces needs two more tools: wasm-tools, which assembles the text into a binary module, and a JavaScript engine with WebAssembly GC support.

Requirements¶

Tool	Version	Needed for
Python	3.12 or later	the compiler itself
uv	recent	installing and running p2w
wasm-tools	recent	assembling WAT into WASM (`p2w -r`, the test suite)
Node.js	22 or later	running a compiled module (`p2w -r`, the test suite)
A browser with WASM GC	recent Chrome or Firefox	running a module in a page

wabt's wat2wasm does not support the GC proposal, so it cannot assemble p2w's output: use wasm-tools.

Installing p2w¶

Install p2w from its repository:

git clone https://git.sr.ht/~sfermigier/p2w
cd p2w
uv sync

uv sync installs p2w and its development tools into .venv. The p2w and p2w-benchmark commands are then available through uv run.

A sibling checkout

p2w depends on abilian-astero, which pyproject.toml takes from a sibling directory, ../astero. Clone it next to p2w before running uv sync.

Installing the tools¶

macOSAny platform, with Cargo

brew install wasm-tools node

cargo install wasm-tools

Then install Node.js 22 or later from nodejs.org or your package manager.

Checking the installation¶

wasm-tools --version
node --version          # v22 or later
echo 'print("hello")' > hello.py
uv run p2w -r hello.py  # prints: hello

Node.js versions before 22 do not enable WebAssembly GC by default, and fail to load p2w's modules.