astral-sh/uv

What it does

uv is a Python package and project manager implemented in Rust. It combines the roles of pip, pip-tools, pipx, poetry, pyenv, twine, and virtualenv in one CLI: resolving and installing dependencies, managing virtual environments, installing Python interpreters, running Python-packaged tools, and locking project dependencies into a universal lockfile (highlights). The main draw is speed: the project publishes benchmarks claiming 10–100x faster installs than pip, and its global cache deduplicates files across the cache to reduce disk use (cache documentation).

It is aimed at Python developers who manage dependencies in applications, libraries, scripts, or monorepos, and at teams that want reproducible lockfiles and Cargo-style workspaces (workspaces). A uv pip interface provides drop-in replacements for common pip commands, so existing workflows can adopt uv without rewriting scripts (pip interface).

Quick start

On macOS or Linux, install uv with the standalone installer:

curl -LsSf https://astral.sh/uv/install.sh | sh

On Windows, use the PowerShell installer:

powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"

You can also install from PyPI with pip install uv or pipx install uv; standalone installations can update themselves with uv self update (installation section). Once installed, create and work in a project:

uv init example
cd example
uv add ruff
uv run ruff check
uv lock
uv sync

uv init creates the project, uv add records the dependency, uv run executes the tool inside the project environment, uv lock resolves the full dependency set into the lockfile, and uv sync brings the environment in line with it (project example).

The same binary covers single-file scripts (uv add --script example.py requests then uv run example.py), ephemeral tools (uvx pycowsay 'hello world!'), Python version management (uv python install 3.12 3.13), and pip-style workflows (uv pip compile, uv venv, uv pip sync) (scripts, tools, Python versions, pip interface).

Constraints

uv supports macOS, Linux, and Windows (README); exact platform support is documented separately (platform support). The README states uv is stable and suitable for production, with a versioning policy covering compatibility. The installer snippets download and execute remote scripts, which is the project's own distribution method — review them before running, as with any installer. The project is dual-licensed under Apache-2.0 or MIT at your option. It is maintained by Astral, the company behind Ruff and ty.

HotRepo's take

uv's most-discussed thread on Hacker News collected 753 points and 336 comments in June 2025, with users describing the switch away from pip and venv, often in response to shared servers with no root access or storage quotas (discussion). The debate also has a technical edge: a pip maintainer points out uv's warm-install speed comes partly from caching unzipped distributions and hard-linking them — faster, but with cache growth for users running many environments — and the 2026 wheel-cache deduplication thread follows that tradeoff (comment). On the rankings side, uv appeared on the Rust daily list on 2026-11-07, gaining 133 stars and reaching 10th, which fits a tool with broad Python adoption despite being written in Rust.