abi3info 2025.11.29

A library for abi3 and other CPython API information

abi3info

abi3info exposes information about CPython's "limited API" (including the stable ABI, called abi3) as a Python library.

Installation

abi3info is available via pip:

$ pip install abi3info

Usage

abi3info exposes limited API and stable ABI information in the form of a set of top-level dictionaries, namely:

import abi3info

abi3info.FEATURE_MACROS
abi3info.MACROS
abi3info.STRUCTS
abi3info.TYPEDEFS
abi3info.FUNCTIONS
abi3info.DATAS

Each of these is a mapping of a name (either as str or Symbol) to a data model describing the kind of item (e.g. FeatureMacro or Function).

See the generated documentation for more details, including comprehensive type hints and explanations of each data model.

See also the stable_abi.toml file, taken from the CPython sources, which describes each model and their semantics.

Examples

Get information about a particular function:

from abi3info import FUNCTIONS
from abi3info.models import Symbol

func = FUNCTIONS[Symbol("_Py_NegativeRefcount")]
print(func.symbol, func.added, func.ifdef, func.abi_only)

Get information about the feature macros that control the limited API:

from abi3info import FEATURE_MACROS

print(fm for fm in FEATURE_MACROS.values())

Licensing

abi3info is licensed under the MIT license.

abi3info is partially generated from metadata retrieved from the CPython sources, which is licensed under the PSF license.