A fast type checker and language server for Python
Star History
Momentum
+176
STARS · LAST 30 DAYS
6
PER DAY
#97
MOST-STARRED Rust
| Window | 7 days | 30 days | 90 days |
|---|---|---|---|
| Stars gained | +42 | +176 | +540 |
| Per day | 6 | 6 | 6 |
| Forks gained | +3 | +10 | +26 |
pyrefly gained 176 stars in the last 30 days, about 6 a day, and now has 7K. It is about 2 years old and has averaged roughly 3.5K stars a year. It ranks #97 among Rust repositories and #882 across all languages on GitHubRepo.
Trending Record
6
DAYS ON TRENDING
#324
BEST RANK
Sep 23, 2026
FIRST APPEARANCE
Active
STATUS TODAY
pyrefly has maintained a continuous presence across global trending indexes, peaking at #324. Below is the 30-day activity profile:
💡 Overview
pyrefly is an open-source project written in Rust: A fast type checker and language server for Python.
Engineered for speed, consistency, and developer ease, it solves common hurdles in code-quality, ide, language-server. It provides clear interfaces, comprehensive configuration options, and seamless integration with existing tools across the modern development stack.
⚡ Key Features
Optimized execution pipeline written in Rust for predictable speed.
Zero-friction configuration with comprehensive sensible defaults out of the box.
Cross-platform runtime support across Linux, macOS, and Windows environments.
Strong typing and modular architecture designed for easy extension and maintainability.
Standardized CLI and API interfaces for smooth integration into CI/CD workflows.
Active community maintenance with regular dependency updates and security patches.
📥 Installation
$ cargo install pyrefly⚙ System Requirements
Platforms
- • macOS
- • Linux
- • Windows
Runtime & Dependencies
Rust toolchain (rustc / cargo >= 1.70)
Architecture
x86_64, ARM64 (Apple Silicon & Graviton)
🧠 How It Works
pyrefly coordinates its core functionality through a modular Rust pipeline. It parses configuration parameters, validates inputs, and resolves dependencies asynchronously. By minimizing runtime overhead and keeping allocations localized, it delivers predictable performance in both local development environments and automated production workloads.
🎯 Production Use Cases
Production System Integration
Embed pyrefly into Rust backend services to handle core application logic.
CI/CD Automated Pipelines
Run automated validation, builds, and integration suites during deployments.
Developer Tooling & Workflows
Accelerate developer onboarding with pre-configured project utilities.
Open Source Extension
Fork and customize internal modules under the repository's open MIT license.
🚀 Getting Started
Install pyrefly using your package manager: `cargo install pyrefly`
Initialize your project workspace or configuration file for pyrefly.
Import pyrefly into your codebase or invoke it directly from your terminal.
Execute your test suite or run `pyrefly --help` to verify successful setup.
👍 Strengths
⚠️ Considerations
⇄ Alternatives & Direct Competitors
👥 Who Should Use This
Developers and engineering teams building with Rust, seeking reliable, tested, and actively maintained tooling for production workloads.
🏆 Nearby in the Rankings
facebook/pyrefly is currently ranked #882 by stars across every repository tracked on GitHubRepo. These are adjacent projects:
| Rank | Repository | Language | Stars | Action |
|---|---|---|---|---|
| #876 | cosmos/cosmos-sdk | Go | ★ 7.1K | Compare ↗ |
| #878 | junit-team/junit-framework | Java | ★ 7.1K | Compare ↗ |
| #879 | repowise-dev/repowise | Python | ★ 7.1K | Compare ↗ |
| #880 | agones-dev/agones | Go | ★ 7.1K | Compare ↗ |
| #881 | paper-trail-gem/paper_trail | Ruby | ★ 7K | Compare ↗ |
| #882 | facebook/pyrefly This Project | Rust | ★ 7K | |
| #882 | facebook/sapling | Rust | ★ 7K | Compare ↗ |
| #884 | massCodeIO/massCode | TypeScript | ★ 7K | Compare ↗ |
| #884 | tamaratran/fast-jev-compaction | TypeScript | ★ 7K | Compare ↗ |
| #886 | evidence-dev/evidence | TypeScript | ★ 7K | Compare ↗ |
| #887 | rakanki911/DLSS5-Swapper | JavaScript | ★ 6.9K | Compare ↗ |
Frequently Asked Questions
What does pyrefly do? +
A fast type checker and language server for Python
What language is pyrefly written in? +
The primary language is Rust. Topics include: code-quality, ide, language-server, language-server-protocol, lsp.
Is pyrefly actively maintained? +
Yes, the last recorded push was on Sep 28, 2026 with 687 open issues being tracked.
How many stars does pyrefly have? +
pyrefly has 7,022 stars and 522 forks on GitHub.
How does pyrefly rank among GitHub repositories? +
With 7,022 stars, facebook/pyrefly is ranked #882 globally across all repositories tracked on GitHubRepo and #97 among Rust projects.
What license is pyrefly distributed under? +
The repository reports a MIT license. Always verify the repository LICENSE file for legal terms.
