Crates

uv is a Cargo workspace. Every piece of functionality lives in a separate crate under crates/. The workspace is defined in the root Cargo.toml; each crate exposes a focused API and depends on a small set of others to keep the dependency graph acyclic.

The Astral team considers the workspace members internal — they're published to crates.io to make the binary buildable from source, but breaking changes are allowed between releases. The user-stable API is the uv CLI itself.

This page lists every crate, organized by role. Each named crate has a dedicated page that explains its purpose, layout, and key types in more depth.

Top-level binary

Crate	Description
uv	The command-line interface and command implementations. The uv and uvx binaries are produced from this crate.
uv-cli	Clap argument schema for every subcommand. ~8000 lines of derive types describing the entire surface area.
uv-dev	Development utilities and code generators (cargo dev generate-all).
uv-bench	Benchmark harnesses for the resolver and installer.
uv-test	Shared test utilities used across integration tests.

Resolution and locking

Crate	Description
uv-resolver	Universal dependency resolver, lockfile (uv.lock), and Pylock TOML emission.
uv-distribution	Fetches metadata for built and source distributions.
uv-distribution-types	Type definitions for distributions, indexes, requirements, and resolution.
uv-distribution-filename	Wheel and sdist filename parsing.
uv-platform-tags	PEP 425 platform tag parsing and inference.
uv-pep440	PEP 440 versions, specifiers, and ranges.
uv-pep508	PEP 508 requirements and markers.
uv-pypi-types	Wire types shared with PyPI Simple/JSON APIs and core metadata.
uv-types	Trait abstractions to break circular dependencies between resolution and build/install.

Installation and environments

Crate	Description
uv-installer	Plan, prepare, and install wheels into a venv; bytecode compilation.
uv-install-wheel	Low-level wheel layout and unpacking.
uv-virtualenv	Pure-Rust replacement for python -m venv.
uv-tool	Per-tool installations and tool environment management.

Python interpreters

Crate	Description
uv-python	Interpreter discovery, querying, and managed Python downloads.
uv-trampoline-builder	Embeds the Windows console-script trampoline binaries built from crates/uv-trampoline/.
uv-shell	Detect and integrate with the active shell for completions and PATH updates.

HTTP, cache, and storage

Crate	Description
uv-client	Cached HTTP client for PyPI-compatible registries (Simple HTML and JSON).
uv-cache	Filesystem cache layout, locking, and removal.
uv-cache-info	Cache metadata helpers (timestamps, freshness).
uv-cache-key	Generic key derivation for caching paths, URLs, and other resources.
uv-fs	Filesystem helpers, locked files, atomic writes, simplified paths.
uv-extract	Tar/zip extraction with hashing for sdists and wheels.
uv-metadata	PEP 658 / Core metadata parsing.

Builds

Crate	Description
uv-build-frontend	PEP 517 build frontend that calls into other backends.
uv-build-backend	uv's own PEP 517 build backend (uv_build).
uv-build	The PyPI distribution shell for the build backend.

Configuration

Crate	Description
uv-workspace	pyproject.toml parsing, workspace discovery, and mutable TOML edits for uv add/uv remove.
uv-settings	uv.toml schema and hierarchical configuration discovery.
uv-configuration	Typed enums for resolution and build modes.
uv-flags	Environment-variable feature flags.
uv-preview	Preview-feature gating for unstable behavior.
uv-static	Compile-time strings and the EnvVars registry.
uv-options-metadata	Metadata used to generate the JSON schema for uv config.
uv-version	The user-facing version constant for uv itself.

Authentication and publishing

Crate	Description
uv-auth	Credential cache, keyring abstraction, and trusted-publishing token retrieval.
uv-keyring	Concrete keyring backends (Secret Service, macOS Keychain, Windows Credential Manager, …).
uv-publish	uv publish upload pipeline with retries, multipart, and OIDC.
uv-redacted	URL types that hide credentials when displayed.

Sources and requirements

Crate	Description
uv-requirements	Project requirements (pyproject.toml, scripts, groups).
uv-requirements-txt	requirements.txt parser with includes and editable spec support.
uv-scripts	PEP 723 inline-metadata scripts.
uv-git	Git source distribution support adapted from Cargo.
uv-git-types	Git URL and revision types.
uv-globfilter	Portable glob filtering used by builds and source-tree walks.

CLI infrastructure and platform glue

Crate	Description
uv-console	Terminal helpers for prompts and human-readable formatting.
uv-warnings	The warn_user / warn_user_once infrastructure.
uv-logging	tracing setup helpers used by the binary.
uv-dirs	Cross-platform directory locations (cache, state, executables).
uv-state	Per-tool/per-Python state directories.
uv-platform	Build-time and runtime platform detection.
uv-windows	Windows-only helpers (junctions, registry helpers).
uv-unix	Unix-only helpers.

Smaller utility crates

Crate	Description
uv-normalize	Package name and extra-name normalization (PEP 503 / 685).
uv-once-map	A waitmap-style concurrent hash map for one-shot tasks.
uv-small-str	Small-string optimization for package names and similar.
uv-fastid	Stable, fast identifiers for resolution.
uv-macros	Workspace-internal proc macros.
uv-dispatch	The orchestrator that wires resolver, builder, and installer together for a given command.
uv-torch	PyTorch-specific index strategies for CUDA/ROCm wheel selection.
uv-audit	uv audit security advisory checks.
uv-bin-install	Bootstrapping helpers for installing native binaries (used by uv self update and friends).
uv-performance-memory-allocator	Conditional mimalloc/jemalloc allocator wiring.
uv-trampoline	Nightly-only no_std Windows trampoline source (excluded from the main workspace).

How they fit together

The crates form a deliberately layered graph:

flowchart TD
    cli[uv-cli] --> uv[uv binary]
    settings[uv-settings] --> uv
    workspace[uv-workspace] --> uv
    uv --> dispatch[uv-dispatch]
    dispatch --> resolver[uv-resolver]
    dispatch --> installer[uv-installer]
    dispatch --> builder[uv-build-frontend]
    resolver --> distribution[uv-distribution]
    distribution --> client[uv-client]
    distribution --> cache[uv-cache]
    installer --> install_wheel[uv-install-wheel]
    installer --> python[uv-python]
    builder --> python
    builder --> virtualenv[uv-virtualenv]
    resolver --> types[uv-types]
    pep440[uv-pep440] --> distribution
    pep508[uv-pep508] --> distribution
    pep440 --> resolver
    pep508 --> resolver

For a top-down tour of how a uv invocation moves through these crates, see Architecture. For walk-throughs that follow specific user journeys (resolution, project workflow, tool execution), see features/.