watchfiles
Simple, modern and high performance file watching and code reload in python.
Decision gist · record as of 2026-08-14
Yes. watchfiles is actively maintained, has no known vulnerabilities, carries a permissive MIT license, and ranks in the top 1000 most-downloaded PyPI packages. The medium install friction (compiled Rust bindings) is offset by broad pre-built wheel coverage and clear documentation. Install it if you need file system monitoring for development or production workflows.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later; if pre-built wheels are unavailable for your platform, Rust stable must be installed to build from source.
- Medium install friction due to compiled Rust bindings, but pre-built wheels are available for most common architectures and Python versions.
- Active maintenance with recent releases.
License · maintenance · safety
MIT (permissive) — MIT license permits commercial and private use with minimal restrictions; suitable for most projects.
last release 2026-05-18 (88 days) · last repo commit 2026-08-09 · 2,522 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 356,540,119 downloads/mo, #115 on PyPI
Alternatives
Verify before relying
from watchfiles import watch
for changes in watch('./path/to/dir'):
print(changes)- Performance characteristics and typical latency for detecting file changes across different file systems
- Memory footprint when monitoring large directory trees with many files
What it is and what it does
watchfiles is a file system monitoring library that detects changes to files and directories, then triggers callbacks or restarts processes in response. It wraps the Notify Rust library to provide efficient, cross-platform file watching with both blocking and async APIs. The package is designed for development workflows—automatically reloading code when source files change—and for general file system event handling. It depends only on anyio for async support and requires Python 3.10 or later.
The library offers four main entry points: watch() for synchronous iteration over file changes, awatch() for async iteration, run_process() to restart a function when files change, and arun_process() for async process restarting. It also includes a CLI tool for running shell commands on file changes. Pre-built wheels are available for Linux, macOS, and Windows across multiple architectures, though platforms without pre-built support require a Rust compiler.
Use it for
- Automatically reload a development server when Python source files are modified
- Monitor a directory and trigger a build or test suite when configuration or source files change
- Watch for changes to a data directory and process new or updated files in an async application
- Implement a CLI tool that re-runs a command whenever files in a watched directory change
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
watchfiles is actively maintained, has no known vulnerabilities, carries a permissive MIT license, and ranks in the top 1000 most-downloaded PyPI packages. The medium install friction (compiled Rust bindings) is offset by broad pre-built wheel coverage and clear documentation. Install it if you need file system monitoring for development or production workflows.
Install
watchfiles on PyPI
Before you install
Medium install friction due to compiled Rust bindings, but pre-built wheels are available for most common architectures and Python versions. Active maintenance with recent releases.
Requires Python 3.10 or later; if pre-built wheels are unavailable for your platform, Rust stable must be installed to build from source.
License in practice
MIT license permits commercial and private use with minimal restrictions; suitable for most projects.
Quickstart
from watchfiles import watch
for changes in watch('./path/to/dir'):
print(changes)Verify before relying
- Performance characteristics and typical latency for detecting file changes across different file systems
- Memory footprint when monitoring large directory trees with many files
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.10 |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | 1 packageanyio |
| Maintenance | Actively maintained 88 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 356,540,119 / month, #115 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableEnvironment :: ConsoleEnvironment :: MacOS XFramework :: AnyIOIntended Audience :: DevelopersIntended Audience :: Information TechnologyIntended Audience :: System AdministratorsLicense :: OSI Approved :: MIT LicenseOperating System :: MacOSOperating System :: Microsoft :: WindowsOperating System :: POSIX :: LinuxProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.15Topic :: Software Development :: Libraries :: Python ModulesTopic :: System :: Filesystems |
Evidence: watchfiles-1.2.0-cp310-cp310-macosx_10_12_x86_64.whl; watchfiles-1.2.0-cp310-cp310-macosx_11_0_arm64.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_17_i686.manylinux2014_i686.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_17_s390x.manylinux2014_s390x.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl; watchfiles-1.2.0-cp310-cp310-manylinux_2_31_riscv64.whl; watchfiles-1.2.0-cp310-cp310-musllinux_1_1_aarch64.whl; watchfiles-1.2.0-cp310-cp310-musllinux_1_1_x86_64.whl; watchfiles-1.2.0-cp310-cp310-win32.whl; watchfiles-1.2.0-cp310-cp310-win_amd64.whl; watchfiles-1.2.0-cp311-cp311-macosx_10_12_x86_64.whl; watchfiles-1.2.0-cp311-cp311-macosx_11_0_arm64.whl; watchfiles-1.2.0-cp311-cp311-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; watchfiles-1.2.0-cp311-cp311-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; watchfiles-1.2.0-cp311-cp311-manylinux_2_17_i686.manylinux2014_i686.whl; watchfiles-1.2.0-cp311-cp311-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl; watchfiles-1.2.0-cp311-cp311-manylinux_2_17_s390x.manylinux2014_s390x.whl
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