
Research
/Security News
Fake imToken Chrome Extension Steals Seed Phrases via Phishing Redirects
Mixed-script homoglyphs and a lookalike domain mimic imToken’s import flow to capture mnemonics and private keys.
check-sdist
Advanced tools
Have you ever shipped broken SDists with missing files or possibly dirty SDists
with files that shouldn't have been there? Have you noticed that standards
compliant tools aren't making the same SDist that flit build is? Is hatchling
adding .DSStore files when you ship from your macOS? No matter what
build-backend you use, check-sdist can help!
Check-sdist builds an SDist and compares the contents with your Git repository contents. It can even temporarily inject common junk files (like pycache files or OS specific files) and help verify that those aren't getting bundled into your SDist. If you are getting files you didn't expect or missing files you did expect, consult your build backend's docs to see how to include or exclude files.
To run with pipx:
$ pipx run check-sdist[uv]
Or, if you like uv instead (faster):
$ uvx check-sdist
You can add --no-isolation to disable build isolation (faster, but must
preinstall build dependencies), --source-dir to select a different source
directory to check, and --inject-junk to temporarily inject some common junk
files while running. You can select an installer for build to use with
--installer=, choices are uv, pip, or uv|pip, which will use uv if
available (the default).
If you need the latest development version:
$ pipx run --spec git+https://github.com/henryiii/check-sdist check-sdist
$ uvx --from git+https://github.com/henryiii/check-sdist check-sdist
To use the pre-commit integration, put this in your
.pre-commit-config.yaml:
- repo: https://github.com/henryiii/check-sdist
rev: v1.4.0
hooks:
- id: check-sdist
args: [--inject-junk]
additional_dependencies: [] # list your build deps here
This requires your build dependencies, but in doing so, it can cache the
environment, making it quite fast. The installation is handled by pre-commit;
see pre-commit-uv if you want to try to
optimize the initial setup. You can also use prek,
which is a Rust pre-commit compatible runner that uses uv. If uv is present
(including in your additional_dependencies), the build will be slightly
faster, as uv is used to do the build. If you don't mind slower runs and don't
want to require a build dependency listing:
- repo: https://github.com/henryiii/check-sdist
rev: v1.4.0
hooks:
- id: check-sdist-isolated
args: [--inject-junk]
This one defaults to including uv in additional_dependencies; you shouldn't
have to specify anything else.
To configure, these options are supported in your pyproject.toml file:
[tool.check-sdist]
sdist-only = []
git-only = []
default-ignore = true
recurse-submodules = true
mode = "git"
build-backend = "auto"
You can add .gitignore style lines here, and you can turn off the default
ignore list, which adds some default git-only files.
By default, check-sdist recursively scans the contents of Git submodules, but you can disable this behavior (e.g. to support older Git versions that don't have this capability).
You can also select mode = "all", which will instead check every file on your
system. Be prepared to ignore lots of things manually, like *.pyc files, if
you use this.
You can tell check-sdist to look for exclude lists for a specific build backend
with build-backend, or "none" to only use it's own exclude list. Build
backends supported are "flit_core.buildapi", "hatchling.build",
"scikit_build_core.build", "pdm.backend", "maturin", and
"poetry.core.masonry.api". The default, "auto", will try to detect the build
backend if build-system.build-backend is set to a known value.
check-sdist will ignore *.dist-info in SDists, since those are generated. If
the build backend is clearly setuptools and default-ignore is on, it will also
ignore *.egg-info and setup.cfg, as setuptools can generate this. If you've
wrapped your build backend, you'll need to add this to the sdist-only ignore
list manually.
If default-ignore is on, a few common generated file settings will be read and
included in sdist-only:
version_file in pyproject.toml only,
write_to is not supported)generate featureFAQs
Check the contents of an SDist vs. git
We found that check-sdist demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Research
/Security News
Mixed-script homoglyphs and a lookalike domain mimic imToken’s import flow to capture mnemonics and private keys.

Security News
Latio’s 2026 report recognizes Socket as a Supply Chain Innovator and highlights our work in 0-day malware detection, SCA, and auto-patching.

Company News
Join Socket for live demos, rooftop happy hours, and one-on-one meetings during BSidesSF and RSA 2026 in San Francisco.