This means we can now take any C/Rust/whatever extension for Python, compile that as a `.wasm` extension, and then load it directly in browser Pyodide projects using:
await micropip.install("package-on-pypi")
import package_name
import micropip
await micropip.install("pydantic_core")
import pydantic_core
You can tell that it's got compiled code in (and not just Python) by running:
pydantic_core._pydantic_core
<module 'pydantic_core._pydantic_core' from '/lib/python3.14/site-packages/pydantic_core/_pydantic_core.cpython-314-wasm32-emscripten.so'>Here's the package: https://pypi.org/project/luau-wasm/
import micropip
await micropip.install("luau-wasm")
import luau_wasm
print(luau_wasm.execute(r'''
local animals = {"fox", "owl", "frog", "rabbit"}
table.sort(animals, function(a, b) return #a < #b end)
for i, name in animals do print(i .. ". " .. name .. " (" .. #name .. ")") end
'''))
Wrote about this in more detail on my blog: https://simonwillison.net/2026/Jun/13/publishing-wasm-wheels...
Something as little as the runtime can just get exploited (which that as happened.) and cause a sandbox escape on the client side. There was a Chrome 0day at the runtime level which allowed untrusted code to run and escape the sandbox in the WASM runtime.
This complete worship of WASM (and their runtimes) as this magical silver bullet reminds me of the days and failures of Native Client (NaCL), Java Applets and Flash all over again.