Status : ALPHA
Release date: 25 August 2025

pyrefly v0.30.0 bundles 195 commits from 20 contributors 👏

✨ New & Improved

🐛 Bug fixes

We closed 11 bug issues this release 👏

• #984 - empty enums incorrectly given type Never, rather than Any
• #865 - completion not working for Pytorch torch.zeros module
• #514 - issue returning generic Self
• Other bug fixes: #971, #967, #743, #567, #348, #261, #186, #103

Thank-you to all our contributors who found these bugs and reported them! Did you know this is one of the most helpful contributions you can make to an open-source project? If you find any bugs in Pyrefly we want to know about them! Please open a bug report issue here

📦 Upgrade

pip install --upgrade pyrefly==0.30

How to safely upgrade your codebase

Upgrading the version of Pyrefly you're using or a third-party library you depend on can reveal new type errors in your code. Fixing them all at once is often unrealistic. We've written scripts to help you temporarily silence them. After upgrading, follow these steps:

1. pyrefly check --suppress-errors
2. run your code formatter of choice
3. pyrefly check --remove-unused-ignores
4. Repeat until you achieve a clean formatting run and a clean type check.

This will add # pyrefly: ignore comments to your code, enabling you to silence errors and return to fix them later. This can make the process of upgrading a large codebase much more manageable.

Read more about error suppressions in the Pyefly documentation

🖊️ Contributors this release

@javabster, @capickett, Carlos Fernandez, @connernilsen , @yangdanny97, @grievejia, @kinto0, @arthaud, @prasannavenkateshgit, @rchen152, @rchiodo, @rubmary, @samwgoldman, @SamChou19815, @sargun, @stroxler, @VladimirMakaev, @migeed-z, @LycheeBay

Status : ALPHA
Release date: 18 August 2025

Pyrefly 0.29 bundles 192 commits from 23 contributors. This release focuses on improving the type checker's behavior, particularly around handling Any and LiteralString, enhancing LSP features like "go to definition" and hover, and various internal refactors for maintainability.

✨ New & Improved

pip install --upgrade pyrefly==0.29

pyrefly v0.28 bundles 119 commits from 20 contributors. This release introduces new features related to function and class metadata, improves class base type calculations, enhances import finding logic, and addresses several bug fixes related to LSP behavior, error reporting, and type inference.

✨ New & Improved

🐛 Other bug fixes

• Fix handling of args and kwargs for lambda functions, where they were incorrectly treated as position arguments.
• Address autocomplete issue where redeclarations were not appearing (reported as #818).
• Fix issues with completions (#850).
• Filter out synthetic narrow keys from named_bindings (#851, #841).
• Improve error suppression logic to handle suppressions on the line above or same line as the error.
• Fix overload selection involving type dict field errors, addressing a bug where an overload that should fail was erroneously selected.
• Fix for #811, where while True with no breaks treated as non-terminating.

🚨 Potentially breaking

If you are using Pyrefly in your CI processes, the following changes may cause your CI to break when upgrading to the new version of Pyrefly

• pyrefly autotype renamed to pyrefly infer to reduce confusion with existing tools.

📦 Upgrade

To upgrade to the latest version of Pyrelfy, run the following terminal command:

pip install --upgrade pyrefly==0.28

🖊️ Contributors this release

Thank-you to all our wonderful contributors!

Aaron Pollack, Abby Mitchell, Adist319, Carlos Fernandez, Conner Nilsen, Danny Yang, Doğaç Eldenk, Fangyi Zhou, Jia Chen, Kyle Into, Maggie Moss, Maxime Arthaud, Neil Mitchell, Rebecca Chen, Rubmary Rojas, Sam Goldman, Sam Zhou, Xavi Simpson, Zeina Migeed

Status: ALPHA

Release date: 2025-08-04

Pyrefly 0.27.0 bundles 212 commits from 20 contributors

📝 Changelog

Typechecking

• Caught exception names are now correctly out of scope after except clauses.
• Variables declared with only annotations (e.g., x: int) are no longer always assumed uninitialized.
• Assignments to inherited attributes within method bodies are no longer treated as re-declarations.
• Prevented crashes from overlapping UsageLink ranges by using YieldLink for yield calculations.
• Corrected the type for __path__ to MutableSequence.

IDE

• Overloads are now supported on completion and metaclass/__new__/__init__ calls are treated as overloads.
• cls arguments are removed from completion and signature help.
• VSCode extension name issue resolved by using displayName in package.json.
• Docstring indentation trimming now ignores the first line.
• More concise display for top-level types
• Function arguments in hover types are formatted on new lines if there's more than one.

Misc.

• Fix crash when receiving non-file change events.

📦 Upgrade

pip install --upgrade pyrefly==0.27.0

🖊️ Contributors this release

@stroxler @fangyi-zhou @rubmary @kinto0 @grievejia @rchen152 @ndmitchell @aahanaggarwal @javabster @connernilsen @migeed-z @SamChou19815 @yangdanny97

Full Changelog: https://github.com/facebook/pyrefly/compare/0.26.0..0.27.0

Status: ALPHA

Release date: 2025-07-28

Pyrefly 0.26.0 bundles 179 commits from 24 contributors

📝 Changelog

Configuration

• Added a "disable-search-path-heuristics" to disable search path heuristics for users that want to configure all imports manually.
• Fixed issues with the --watch flag.
• Support .pyx, .pyd, and .pyw compiled files for module finding and globbing.
• Disabled imports from pycache to prevent incorrect imports.

Typechecking Features

• Fix several bugs with variable scopes.
• Warn on calling deprecated overloads.
• Added support for checking code snippets directly from the command line.
• Disallowed attribute assignment or deletion on super() objects.
• Emit an error when an uncalled function is used as the condition for an if statement.
• Improved new and init_subclass behavior.
• Enabled support for descriptors in dataclass fields.
• Fixed bugs related to TypedDict operations, including setitem and matching against PartialTypedDict.
• Fix bug with synthesized namedtuple constructors.

IDE

• Optimized autocomplete by filtering local variable results and providing a specialized path for builtins, effectively improving auto-import behavior.

Other

• Enhanced performance with caching for node packages and rust-cache.
• Improved display of default values and type information.
• Improved subscript error messages to indicate non-subscriptable types.
• Summary display is now more concise by default, with options for detailed or no summary.

📦 Upgrade

pip install --upgrade pyrefly==0.26.0

🖊️ Contributors this release

@grievejia @samwgoldman @stroxler @rchen152 @fangyi-zhou @ndmitchell @rubmary @kinto0 @arthaud @lolpack @migeed-z @darricklaidin @connernilsen @regexyl @danielocfb @WeixiMa @maggiemoss @yangdanny97

Full Changelog: https://github.com/facebook/pyrefly/compare/0.25.0..0.26.0

Status: ALPHA

Release date: 2025-07-22

Pyrefly 0.25.0 bundles 307 commits from 19 contributors

📝 Changelog

• Error Handling Improvements:
  • Avoid redundant error messages for positional arguments.
  • Show environment query errors and config loading errors in IDE.
• Class and Attribute Handling:
  • Changed semantics of class objects initialized on class bodies.
  • Improved handling of read-only class attributes.
• IDE Enhancements:
  • Support for "jump to definition" on hover.
  • Optimized module path sorting.
• Type System Enhancements:
  • Improve handling for typing.Self.
• Configuration and Migration:
  • Added support for ignore_missing_imports in Pyrefly config.
  • Improved config migration logic and added tests for various config options.
• Error and Warning Enhancements:
  • Warn on deprecated method calls and overloaded calls.
  • Improve error labeling and severity-based color coding.
• TypedDict Improvements:
  • Check keyword arguments in TypedDict initialization & makeself positional-only.
• Documentation and Usability:
  • Updated documentation for IDE settings and config options.
• Miscellaneous:
  • Raise error on variable use-before-assignment.
  • Improved mutable capture for global and nonlocal variables.

📦 Upgrade

pip install --upgrade pyrefly==0.25.0

🖊️ Contributors this release

@rchen152 @stroxler @ndmitchell @yangdanny97 @arthaud @kinto0 @connernilsen @SamChou19815 @rubmary @dluo @migeed-z @samwgoldman @fangyi-zhou @LyricalToxic @melvinhe @grievejia @lolpack

Full Changelog: 0.24.2...0.25.0

Status: ALPHA

Release date: 2025-07-15

Pyrefly 0.24.2 bundles 290 commits from 26 contributors

📝 Changelog

• Type System Enhancements: Improved handling of type() and bool() for narrowing, and the behavior for match statements w/ class patterns
• Dataclass Transform: Full support for dataclass_transform
• Interpreter Query Optimization: Significant reduction in import times and memory usage by optimizing search path handling and deduplication of search path entries.
• Error Handling and Reporting: Introduced CLI flags to configure error severity for individual error codes (--error, --warn, --ignore) and improved error message clarity.
• Semantic Tokens: Fixed issues with semantic tokens on the first line and improved deduplication logic.
• Binop Support: Fixed issues with operations like float * bool and complex * bool.
• Workspace Symbols: Implemented workspace symbol support using the fuzzy search infrastructure for auto-import.
• Configuration Improvements: Added --typeshed-path CLI flag for custom typeshed modifications and improved config handling logic.

📦 Upgrade

pip install --upgrade pyrefly==0.24.2

🖊️ Contributors this release

@ndmitchell, @yangdanny97, @stroxler, @rchen152, @migeed-z, @connernilsen, @dluo, @maggiemoss, @rubmary, @xaskii, @kinto0, @grievejia, @SamChou19815, @melvinhe, @lianne, @krikera, @dluo, @Abel981, @fangyi-zhou, @Alex-Aron, @zpao, @slawlor, @diliop, @arnav-jain1, @samwgoldman

Pyrefly 0.23.0

Status: ALPHA
Release date: 2025-07-07

Pyrefly 0.23.0 bundles 186 commits from 24 contributors. This release introduces significant improvements in type checking, configuration handling, and error management.

📝 Changelog

• Dataclass improvements: Added checks for dataclas field ordering, keyword arguments, and inheritance, aligning with Python's typing specification. Started implementing support for dataclass transforms.
• Error Handling and Suppression: Introduced more robust error handling and suppression options. Error suppression comments can now specify the type of error being suppressed, and are less sensitive to whitespace.
• Go-to-def Enhancements: Added support for resolving a single goto-def request to multiple definitions.
• Configuration and Environment Updates: Better error reporting and support for conda environments.
• Jupyter Notebook Integration: Pyrefly can now work on notebooks in Jupyter Lab, via the jupyterlab-lsp extension.

📦 Upgrade

pip install --upgrade pyrefly==0.23.0

🖊️ Contributors this release

@aahanaggarwal, @yangdanny97, @stroxler, @rchen152, @dluo, @ndmitchell, @connernilsen, @xaskii, @melvinhe, @migeed-z, @TheRustyPickle, @arnav-jain1, @InSyncWithFoo, @rubmary, @arthaud, @samwgoldman, @grievejia, @danielocfb-test, @maggiemoss, @DavidTolnay, @junhao, @darricklaidin, @kinto0

Pyrefly 0.22.0

Status : ALPHA

Release date: 30 Jun 2025

Pyrefly 0.22.0 bundles 216 commits from 23 contributors. This release includes significant improvements in type checking and performance enhancements.

✨ New & Improved

🐛 Other bug fixes

• Fixed bugs in attribute narrowing and method overrides.
• Resolved issues with NamedTuple field ordering and TypedDict method synthesis.
• Values with type[tuple] can now be used as a tuple constructor
• Enums can now be subscripted with any str, not just literals.

📦 Upgrade

pip install --upgrade pyrefly==0.22.0

🖊️ Contributors this release

@Adist319, @adsi7698, @bigfootjon, @connernilsen, @CookieComputing, @dluo, @facebook-github-bot, @fangyi-zhou, @grievejia, @iwakitakuma33, @kinto0, @krathul, @melvinhe, @migeed-z, @ndmitchell, @pt2302, @rchen152, @SamChou19815, @stroxler, @vagabond-0, @xaskii, @yangdanny97, @zsol

Previous Release Notes

https://github.com/facebook/pyrefly/releases

Full Changelog: 0.21.0...0.22.0

Pyrefly 0.21.0

Status : ALPHA
Release date: 23 June 2025

Pyrefly 0.21.0 delivers 176 commits from 20 contributors. We now support a number of highly requested features such as Semantic Highlighting, Signature Help, Document Highlights and Auto Import Completions! Follow along for more LSP functionality #344 ahead of our V1 release.

✨ New & Improved

🐛 Other bug fixes

• Multiple edge-case panics removed, including starred targets inside augmented assignments and cyclic class-type substitutions.
• Hover & go-to-definition in LSP no longer crash when traversing keyword-only or pattern-match bindings.
• Cargo / Rust nightly warnings cleaned up; WASM build green again.

🚨 Potentially breaking

• The new, more explicit override-mismatch diagnostics may fail code that relied on silent attribute-type changes.
• Editors that hard-code semantic-token kinds should be updated to recognise the new defaultLibrary modifier.

📦 Upgrade

pip install --upgrade pyrefly==0.21.0

🖊️ Contributors this release

@yangdanny97 @Adist319 @grievejia @connernilsen @migeed-z @ndmitchell @xl4624 @stroxler @rchen152 @TheRustyPickle @dluo @kinto0 @pt2302 @SamChou19815 @ducdetronquito @xaskii @Alex-Aron @hugovk @grantlouisherman @rubmary