Skip to main content
Pre-release

This release is a pre-release and may not be stable for production use.

Pyrefly: A fast type checker and language server for Python with powerful IDE features

pyrefly PyPI VS Code Open VSX Discord License: MIT

Pyrefly is a type checker and language server for Python, which provides lightning-fast type checking along with IDE features such as code navigation, semantic highlighting, and code completion. It is available as a command-line tool and an extension for popular IDEs and editors such as VSCode, Neovim, Zed, and more.

See the Pyrefly website for full documentation and how to add Pyrefly to your editor of choice.

Pyrefly's current development status is stable.

Key Features

  • Fast. Pyrefly checks over 1.85 million lines of code per second, type checking projects like PyTorch 15x faster than Mypy and Pyright. In the IDE, rechecks typically complete in under 10 milliseconds after saving a file.
  • Production-proven at scale. Pyrefly is the default type checker for Instagram's 20-million-line Python codebase at Meta, and has been adopted by large open source projects including PyTorch and JAX.
  • Full-featured language server. Code navigation, autocomplete, hover information, inlay hints, semantic highlighting, and more, with consistent results across the CLI and your editor of choice.
  • Understands real-world Python. Built-in support for frameworks and tools like Pydantic, Django, and pytest, with model validation, field types, fixture navigation, and autocomplete that work out of the box.
  • Adoption-ready. Migrate from Mypy or Pyright with pyrefly init, silence existing errors with pyrefly suppress, and generate type annotations with pyrefly infer. Start with one file and expand at your own pace.

Getting Started

Version Policy

Pyrefly releases new minor versions (1.x.0) monthly and patch versions in between as-needed for critical fixes. Pyrefly does not follow strict semantic versioning: minor versions contain more significant changes than patch versions, but any version may introduce new type errors and other breaking changes. The pyrefly suppress command can be used to easily silence errors when upgrading to a new version.

Getting Involved

If you have questions or would like to report a bug, please create an issue.

See our contributing guide and architecture overview for information on how to contribute to Pyrefly.

Join our Discord to chat about Pyrefly and types. This is also where we hold biweekly office hours.

Metadata

Release files for pyrefly 1.5.0.dev1

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for pyrefly 1.5.0.dev1
File Size Uploaded Provenance Actions
pyrefly-1.5.0.dev1.tar.gz 7.5 MB With provenance Details for pyrefly-1.5.0.dev1.tar.gz

Built distributions (wheels)

Table of built distributions (wheels) for pyrefly 1.5.0.dev1
File Actions
pyrefly-1.5.0.dev1-py3-none-win_arm64.whl Python 3 none Windows ARM64 Details for pyrefly-1.5.0.dev1-py3-none-win_arm64.whl
pyrefly-1.5.0.dev1-py3-none-win_amd64.whl Python 3 none Windows x86-64 Details for pyrefly-1.5.0.dev1-py3-none-win_amd64.whl
pyrefly-1.5.0.dev1-py3-none-win32.whl Python 3 none Windows x86-32 Details for pyrefly-1.5.0.dev1-py3-none-win32.whl
pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_x86_64.whl Python 3 none Linux musl 1.2+ x86-64 Details for pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_x86_64.whl
pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_aarch64.whl Python 3 none Linux musl 1.2+ ARM64 Details for pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_aarch64.whl
pyrefly-1.5.0.dev1-py3-none-manylinux2014_x86_64.manylinux_2_17_x86_64.whl Python 3 none Linux glibc 2.17+ x86-64 Details for pyrefly-1.5.0.dev1-py3-none-manylinux2014_x86_64.manylinux_2_17_x86_64.whl
pyrefly-1.5.0.dev1-py3-none-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl Python 3 none Linux glibc 2.17+ PowerPC 64-le Details for pyrefly-1.5.0.dev1-py3-none-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl
pyrefly-1.5.0.dev1-py3-none-manylinux2014_i686.manylinux_2_17_i686.whl Python 3 none Linux glibc 2.17+ x86-32 Details for pyrefly-1.5.0.dev1-py3-none-manylinux2014_i686.manylinux_2_17_i686.whl
pyrefly-1.5.0.dev1-py3-none-manylinux2014_aarch64.manylinux_2_17_aarch64.whl Python 3 none Linux glibc 2.17+ ARM64 Details for pyrefly-1.5.0.dev1-py3-none-manylinux2014_aarch64.manylinux_2_17_aarch64.whl
pyrefly-1.5.0.dev1-py3-none-macosx_11_0_arm64.whl Python 3 none macOS 11.0+ ARM64 Details for pyrefly-1.5.0.dev1-py3-none-macosx_11_0_arm64.whl
pyrefly-1.5.0.dev1-py3-none-macosx_10_12_x86_64.whl Python 3 none macOS 10.12+ x86-64 Details for pyrefly-1.5.0.dev1-py3-none-macosx_10_12_x86_64.whl

Total release size: 188.2 MB

Release files / pyrefly-1.5.0.dev1.tar.gz

Download URL pyrefly-1.5.0.dev1.tar.gz
Size 7.5 MB
Tags Source
SHA-256 checksum
How to use checksums
9eae53aac2eac44417b9d70d54efe8d9e0855aba589121c2df7337d27d03a8f7
BLAKE2b-256 checksum
How to use checksums
fa4b01de5a1285ad196f2c49a113b992bba9dd18716bdb030a27afedf1e64308
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-win_arm64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-win_arm64.whl
Size 15.6 MB
Tags Python 3 Windows ARM64
SHA-256 checksum
How to use checksums
ac2e6ec84fcf8fed018c72f4456dd3a88681a0205b24776091c86c0608eba314
BLAKE2b-256 checksum
How to use checksums
93df7d0ce69ca1654109f802727a0e4b594a3f7f26d7d0c91e64a3fe89b05da6
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-win_amd64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-win_amd64.whl
Size 16.4 MB
Tags Python 3 Windows x86-64
SHA-256 checksum
How to use checksums
355cbe96d3c09f2dd7bb3a0494fec59e7c822696d9b6a1243e727cc200b9a630
BLAKE2b-256 checksum
How to use checksums
f2ed3b3daa7379e5336cc0a077406380d48c4b8d960f2461852c97cc6042c0d2
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-win32.whl

Download URL pyrefly-1.5.0.dev1-py3-none-win32.whl
Size 15.5 MB
Tags Python 3 Windows x86-32
SHA-256 checksum
How to use checksums
59541c8fdaaade7441d676925d31cb6aec5e37515f100f7e5b21e4257299a4e4
BLAKE2b-256 checksum
How to use checksums
c1f265fc5ac71849c1540e1de4e32a6a48172f216f39fadaeee781d9e9d9f2fc
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_x86_64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_x86_64.whl
Size 16.8 MB
Tags Linux musl 1.2+ x86-64 Python 3
SHA-256 checksum
How to use checksums
e41a85d426106d773c78eaf9fbee55dddd8cf901756f6c2ae647dde3c73a569a
BLAKE2b-256 checksum
How to use checksums
5c9e27ed79e1f56c00f8272dd92639d74edabdaa5e92dcf88d6168d7c04f235c
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_aarch64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-musllinux_1_2_aarch64.whl
Size 16.2 MB
Tags Linux musl 1.2+ ARM64 Python 3
SHA-256 checksum
How to use checksums
032a60ae9a9bb97c4481d92562941319a7ff70f7720438819e9cb4e066a355f4
BLAKE2b-256 checksum
How to use checksums
11268264f940a51abe9e4a1666ee7fea9028c95c5e980d27f504e07ad8d30388
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-manylinux2014_x86_64.manylinux_2_17_x86_64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-manylinux2014_x86_64.manylinux_2_17_x86_64.whl
Size 16.8 MB
Tags Linux glibc 2.17+ x86-64 Python 3
SHA-256 checksum
How to use checksums
4cf453c6e4d0b22f78c91541c8eb6242f7d066877861651fe7f3d31ca0170077
BLAKE2b-256 checksum
How to use checksums
f0bf24146d5134f9604cc03eb69100509b1469c453d14ddb860b8c05cf96619b
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl

Download URL pyrefly-1.5.0.dev1-py3-none-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl
Size 17.5 MB
Tags Linux glibc 2.17+ PowerPC 64-le Python 3
SHA-256 checksum
How to use checksums
b889ace7d73016deaa88ef0f00544f2cc72a5d5ed619aa6526ff6e42dd9f1737
BLAKE2b-256 checksum
How to use checksums
124f04990f7784fa07f54d1feb4bcabebc82ba1fe14d287f598d813a0c7ea325
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-manylinux2014_i686.manylinux_2_17_i686.whl

Download URL pyrefly-1.5.0.dev1-py3-none-manylinux2014_i686.manylinux_2_17_i686.whl
Size 17.6 MB
Tags Linux glibc 2.17+ x86-32 Python 3
SHA-256 checksum
How to use checksums
50625f39acaf0e41078477929190593740ede85869c8adf1f3c274c364ce1533
BLAKE2b-256 checksum
How to use checksums
91c90b7aab8b7f2af32ad7f399ed41a1289aa1262b77a3a495d2be55f2b1f144
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-manylinux2014_aarch64.manylinux_2_17_aarch64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-manylinux2014_aarch64.manylinux_2_17_aarch64.whl
Size 16.1 MB
Tags Linux glibc 2.17+ ARM64 Python 3
SHA-256 checksum
How to use checksums
925966bf86fbae0dc7a315eaeb2f1a97ede23c2eb6a462c805e6473b4ebe7e4c
BLAKE2b-256 checksum
How to use checksums
7e9540e3ced2a08a7deb17f9fd7a8da8328a421f4894e85526d306a9a362ba3f
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-macosx_11_0_arm64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-macosx_11_0_arm64.whl
Size 15.6 MB
Tags Python 3 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
f2426da33d77a0053e93dadb32ade8f0159af5fb0e0c531b2cd578db43d3f1cf
BLAKE2b-256 checksum
How to use checksums
b5afc89b0b1f3d56fefdb7f7711bfda21b0ea03350ffd5f42939c9f0f8d7ae39
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 Nov 4, 2026.

Transparency log

Release files / pyrefly-1.5.0.dev1-py3-none-macosx_10_12_x86_64.whl

Download URL pyrefly-1.5.0.dev1-py3-none-macosx_10_12_x86_64.whl
Size 16.4 MB
Tags Python 3 macOS 10.12+ x86-64
SHA-256 checksum
How to use checksums
91b9bcb7abb3b92b56cce743ea4d743131ef465a9a462637b4178595a7b32f81
BLAKE2b-256 checksum
How to use checksums
dc26e6b5b8068ae10c15aae262ab9454a48af41c38544c8ae25ebaa6085f58c7
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 Nov 4, 2026.

Transparency log

Security for pyrefly 1.5.0.dev1

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.

Full provenance

All 12 files in this release have been uploaded with provenance metadata.

Select from 12 files

Attestation for pyrefly-1.5.0.dev1.tar.gz

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 Nov 4, 2026.

Transparency log

A note on package security

PyPI is a repository for distributing packages, not a service for auditing them. While third-party security researchers and our staff do their best to detect and remove malicious packages, PyPI cannot guarantee the quality, security or suitability of any given package.

To learn more about protecting yourself from malicious actors, visit our package security documentation.

Release history Release notifications | RSS feed

This release
Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page