abi3info
A library for abi3 and other CPython API information
Decision gist · record as of 2026-08-14
Yes, if you work with CPython's C API or stable ABI. It eliminates the need to manually parse CPython sources or maintain your own ABI metadata. No runtime dependencies, low friction, permissive license, and actively maintained. Not relevant for pure-Python projects.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later.
- Low friction: pure Python wheel with no runtime dependencies.
- Actively maintained as of 2026-06-10, with production-stable status and consistent release cadence since 2022-09-19.
License · maintenance · safety
MIT (permissive) — MIT license (permissive) with metadata derived from CPython sources under the PSF license. You can use this library freely in commercial or proprietary projects.
last release 2025-11-29 (258 days) · last repo commit 2026-06-10 · 9 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 439,597 downloads/mo, #6,653 on PyPI
Alternatives
Verify before relying
pip install abi3info
from abi3info import FUNCTIONS
from abi3info.models import Symbol
func = FUNCTIONS[Symbol("_Py_NegativeRefcount")]
print(func.symbol, func.added, func.ifdef, func.abi_only)- Whether the stable_abi.toml metadata is updated with each CPython release or on a different schedule.
- Performance characteristics when iterating over large numbers of symbols or querying frequently.
What it is and what it does
abi3info is a reference library that makes CPython's stable ABI (abi3) metadata programmatically accessible. It parses and exposes information about the limited API—the subset of CPython's C API that remains stable across minor versions—as a set of top-level dictionaries mapping symbol names to structured data models. Each dictionary (FUNCTIONS, MACROS, STRUCTS, TYPEDEFS, DATAS, FEATURE_MACROS) holds metadata about the corresponding API element, including when it was added, any preprocessor guards, and whether it's ABI-only.
This is useful for developers working with CPython's C extension interface, particularly those building or analyzing tools that depend on the stable ABI. Rather than parsing CPython's source files directly, you can query abi3info to check whether a symbol exists, what Python version introduced it, and what conditions govern its availability. The library is actively maintained and draws its data from CPython's own stable_abi.toml metadata file.
Use it for
- Check which stable ABI symbols are available in a target Python version before writing C extension code.
- Validate that a C extension only uses symbols from the stable ABI to ensure forward compatibility.
- Generate documentation or reports about the stable ABI surface and its evolution across CPython releases.
- Analyze feature macros to understand which optional API features are available in a given build.
- Inspect symbol metadata (added version, ifdef guards) to determine compatibility constraints for extension projects.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you work with CPython's C API or stable ABI.
It eliminates the need to manually parse CPython sources or maintain your own ABI metadata. No runtime dependencies, low friction, permissive license, and actively maintained. Not relevant for pure-Python projects.
Install
abi3info on PyPI
Before you install
Low friction: pure Python wheel with no runtime dependencies. Actively maintained as of 2026-06-10, with production-stable status and consistent release cadence since 2022-09-19.
Requires Python 3.10 or later.
License in practice
MIT license (permissive) with metadata derived from CPython sources under the PSF license. You can use this library freely in commercial or proprietary projects.
Quickstart
pip install abi3info
from abi3info import FUNCTIONS
from abi3info.models import Symbol
func = FUNCTIONS[Symbol("_Py_NegativeRefcount")]
print(func.symbol, func.added, func.ifdef, func.abi_only)Verify before relying
- Whether the stable_abi.toml metadata is updated with each CPython release or on a different schedule.
- Performance characteristics when iterating over large numbers of symbols or querying frequently.
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.10 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 258 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 439,597 / month, #6,653 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyTopic :: Security |
Evidence: abi3info-2025.11.29-py3-none-any.whl
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Install only if maintaining existing code that already depends on it, and plan a migration.
See also abi3audit · cxxfilt · pyclibrary · itanium-demangler · pyobjc-framework-Symbols · faster-eth-abi · pydemumble · keysymdef · openbb-imf