ast-serialize

Python bindings for mypy AST serialization

ast-serialize Permissive license MIT Active ★ 9 v0.8.0 released 2026-08-07

Install

ast-serialize on PyPI

pip

pip install ast-serialize

uv

uv add ast-serialize

poetry

poetry add ast-serialize

Package facts

License	MIT (permissive)
Python support	supports the current Python release (>=3.7)
Install friction	medium — platform-specific wheel
Runtime dependencies	none
Maintenance	actively maintained — 6 days since the last release
Last repo commit	2026-08-12
First released	2026-01-28
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: ast_serialize-0.8.0-cp314-cp314-pyemscripten_2026_0_wasm32.whl; ast_serialize-0.8.0-cp314-cp314t-macosx_10_12_x86_64.whl; ast_serialize-0.8.0-cp314-cp314t-macosx_11_0_arm64.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_17_s390x.manylinux2014_s390x.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_17_x86_64.manylinux2014_x86_64.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_31_riscv64.whl; ast_serialize-0.8.0-cp314-cp314t-manylinux_2_5_i686.manylinux1_i686.whl; ast_serialize-0.8.0-cp314-cp314t-musllinux_1_2_aarch64.whl; ast_serialize-0.8.0-cp314-cp314t-musllinux_1_2_armv7l.whl; ast_serialize-0.8.0-cp314-cp314t-musllinux_1_2_i686.whl; ast_serialize-0.8.0-cp314-cp314t-musllinux_1_2_ppc64le.whl; ast_serialize-0.8.0-cp314-cp314t-musllinux_1_2_riscv64.whl; ast_serialize-0.8.0-cp314-cp314t-musllinux_1_2_x86_64.whl; ast_serialize-0.8.0-cp314-cp314t-win32.whl; ast_serialize-0.8.0-cp314-cp314t-win_amd64.whl; ast_serialize-0.8.0-cp314-cp314t-win_arm64.whl; ast_serialize-0.8.0-cp315-abi3.abi3t-macosx_10_12_x86_64.whl

Development Status :: 3 - AlphaEnvironment :: ConsoleIntended Audience :: DevelopersProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.15Programming Language :: Python :: 3.9Programming Language :: RustTopic :: Software DevelopmentTyping :: Typed

About ast-serialize

from the package's own PyPI description — quoted content, verbatim

ast_serialize - Python Parser and AST Serializer

This is a fast Python extension for parsing Python files and serializing the AST using the native binary format used by mypy. This will eventually replace the current mypy parser, which uses the Python stdlib ast module for parsing.

This is work in progress.

Development

Prerequisites:

Recent Rust toolchain
Python 3.10+ (3.13t or 3.14t for free-threaded builds)
maturin: pip install maturin
Checkout of mypy repo for testing

Development build (fast compilation, unoptimized):

maturin develop

Optimized development build:

maturin develop --release

Testing

Rust unit tests:

cargo test

Python integration tests: Run end-to-end parser and serialization/deserialization tests using mypy's test suite in the new-parser branch:

cd ~/src/mypy  [or wherever you have mypy]
pytest mypy -k NativeParser

Add new test cases to test-data/unit/native-parser.test (in the mypy repository). See the main parser test cases in parse.test for the expected output format.

Note: Run `maturin...

Read as markdown · JSON record · Source repository · Homepage

AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

A fast Python extension that parses Python source files and serializes their abstract syntax trees using mypy's native binary format, intended to eventually replace mypy's stdlib-based parser.

Medium install friction due to compiled wheels for multiple Python versions and architectures; actively maintained with a release 6 days ago and recent commits, though the project is marked as alpha (Development Status 3) and explicitly noted as work in progress.

MIT license permits commercial and private use with minimal restrictions, making it suitable for integration into type checkers and development tools.

Usage

pip install ast-serialize==0.8.0
import ast_serialize
# Parse and serialize Python code using mypy's native format
result = ast_serialize.parse("x = 1")

Requires Python 3.7+; free-threaded builds (3.13t, 3.14t) need the corresponding CPython free-threaded interpreter installed.

Verdict: A young but actively maintained Rust-based parser designed for mypy integration, offering performance gains over stdlib ast. Zero known vulnerabilities and permissive licensing make it safe to evaluate, but alpha status and tight coupling to mypy's development cycle mean it is not yet a general-purpose replacement for standard parsing.

Needs verification

Whether ast_serialize's output format is stable across versions or subject to breaking changes during alpha development.
Performance benchmarks comparing ast_serialize to stdlib ast module for typical use cases.
Whether the package can be used independently of mypy or is primarily intended as an internal mypy component.

python ast parser serializermypy native parserfast python parsingast binary serializationpython code analysismypy ast formatrust python parser