The missing PEP 517 build backend for C extensions.
You know how to build your project. just-buildit knows how to package it. That's the whole deal.
The problem
Every existing Python build backend either wants to own your build system, assumes you're using setuptools extensions, or drags in a dependency tree bigger than your project. There's no option that just says:
"Here are your C files. Build them however you want. I'll ship the result."
just-buildit is that option.
Installation
pip install just-buildit
Quickstart
Flat layouts, nested packages, multiple extensions across subdirectories, mixed pure Python and C — whatever your build produces.
Zero config — a single C extension in src/mylib/:
[build-system]
requires = ["just-buildit"]
build-backend = "just_buildit"
[project]
name = "mylib"
version = "0.1.0"
Run pip install . and just-buildit finds src/mylib/, compiles every .c
file it contains, and ships the result.
Custom build command — Make, CMake, Meson, Bazel, or anything else:
[tool.just-buildit]
command = "make"
just-buildit sets environment variables, calls your command, and packages
everything written to $JUST_BUILDIT_OUTPUT_DIR.
Need a project scaffold? just-makeit generates a CMake-based C extension project pre-wired for just-buildit — see the examples.
CLI
uvx just-buildit inspect # dry-run: show config and what would be built
uvx just-buildit build # build wheel into dist/
uvx just-buildit sdist # build source distribution into dist/
# For a project deriving its version from git tags, the number CI cannot
# read out of a file, because there is no longer a file carrying it:
uvx just-buildit --next-version # -> 1.1.4 (the tag a release would push)
Documentation
| Environment variables | What just-buildit sets before calling your command |
| Examples | Make, CMake, Meson, Bazel, mixed Python + C, nested packages |
| Configuration | Full config reference, wheel repair, editable installs |
| Contributing | Running tests, platform support, bootstrapping |
Requirements
- Python 3.8+
- A compiler (you already have one)
uvfor wheel repair (uvx auditwheel/uvx delocate-wheel/uvx delvewheel)
Authors
Matthew T. Hunter, Ph.D. and Claude Code
License
MIT
1 maintainer
Release files for just-buildit 0.5.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| just_buildit-0.5.0.tar.gz | 195.3 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| just_buildit-0.5.0-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 233.0 kB
Release files / just_buildit-0.5.0.tar.gz
| Download URL | just_buildit-0.5.0.tar.gz |
|---|---|
| Size | 195.3 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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|
|
BLAKE2b-256 checksum How to use checksums |
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| Upload date | |
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Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
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Provenance
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Signed by GitHub Actions, verified by PyPI on Sep 9, 2026.
Transparency logRelease files / just_buildit-0.5.0-py3-none-any.whl
| Download URL | just_buildit-0.5.0-py3-none-any.whl |
|---|---|
| Size | 37.7 kB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
d52dbd16a2374387f0091310a8598dc10f3122506bfb48ed788677400a656c5e
|
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BLAKE2b-256 checksum How to use checksums |
d0914f5a2552b978f99418cb17160838096653c90b280b5329d3a6295e1a3d23
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Sep 9, 2026.
Transparency log
