Programming Language
- Python
- Python :: 3
- Python :: 3.9
- Python :: 3.10
- Python :: 3.11
- Python :: 3.12
- Python :: 3.13
- Python :: 3.14
- Python :: Implementation :: CPython
- Python :: Implementation :: PyPy
- Rust
Topic
- Software Development :: Compilers
- Software Development :: Interpreters
Installation
To install wasmtime-py, run this command in your terminal:
$ pip install wasmtime
The package currently supports 64-bit builds of Python 3.9+ on Windows, macOS, and Linux, for x86_64 and arm64 architectures.
Versioning
wasmtime-py follows the Wasmtime versioning scheme, with a new major version being
released every month. As with Wasmtime itself, new major versions of wasmtime-py
can contain changes that break code written against the previous major version.
Since every installed Python package needs to agree on a single version of
wasmtime-py, to use the upper bound on the major version in the dependency
requirement should be bumped reguarly, ideally as soon as a new wasmtime-py
version is released. To automate this process it is possible to use
the whitequark/track-pypi-dependency-version script. YoWASP/runtime is
an example of a project that automatically publishes releases on PyPI once a new
version of wasmtime-py is released if it passes the testsuite.
Usage
In this example, we compile and instantiate a WebAssembly module and use it from Python:
from wasmtime import Store, Module, Instance, Func, FuncType
store = Store()
module = Module(store.engine, """
(module
(func $hello (import "" "hello"))
(func (export "run") (call $hello))
)
""")
def say_hello():
print("Hello from Python!")
hello = Func(store, FuncType([], []), say_hello)
instance = Instance(store, module, [hello])
run = instance.exports(store)["run"]
run(store)
Be sure to check out the examples directory, which has other usage patterns
as well as the full API documentation of the wasmtime-py package.
Components
Components are also supported in wasmtime-py. For more information see the
documentation of
wasmtime.component.
Using a component is similar to using core wasm modules, and for examples see
the tests/component/ directory.
Contributing
See CONTRIBUTING.md.
