# pycu
[](https://github.com/Logic-py/python-check-updates/actions/workflows/ci.yml)
[](https://codecov.io/gh/Logic-py/python-check-updates)
[](https://github.com/Logic-py/python-check-updates/releases/latest)
[](https://crates.io/crates/pycu)
[](LICENSE-MIT)
A fast CLI that checks your Python project dependencies against PyPI and reports which ones have newer versions
available. Inspired by [npm-check-updates](https://github.com/raineorshine/npm-check-updates).
```
fastapi >=0.109.0 → >=0.135.1
pydantic >=1.10.0 → >=2.12.5
uvicorn >=0.20 → >=0.34.0
3 packages can be updated.
```
## Why I built this
Every week I'd open my Python projects, manually scan through `pyproject.toml`, look up each package on PyPI, and check
whether I was falling behind. It was tedious, easy to miss something, and I kept thinking there has to be a better way.
There were existing tools, but none of them fit quite how I worked. I'd been spoiled
by [npm-check-updates](https://github.com/raineorshine/npm-check-updates) in the Node world: one command, instant table,
upgrade in place if you want. I wanted exactly that, but for Python something fast, dependency-file-aware, and with
in-place upgrades that actually respected my version constraints.
So I built pycu.
## Features
- Supports `pyproject.toml` (PEP 621 / uv), `pyproject.toml` (Poetry), and `requirements.txt`
- Concurrent PyPI lookups with configurable parallelism
- In-place upgrades with `--upgrade`
- Filter by bump level: major, minor, or patch only
- JSON output for scripting
- Self-updates via `--self-update`
- Color-coded output showing exactly which version component changed, with 5 built-in color schemes including
color-blind safe options
- SHA-256 verified self-update downloads
## Installation
### Linux / macOS
```sh
### Windows (PowerShell)
```powershell
### Manual download
Download the binary for your platform from
the [latest release](https://github.com/Logic-py/python-check-updates/releases/latest), extract it, and place it
somewhere on your `PATH`.
### From source
Requires [Rust](https://rustup.rs) 1.85 or later (edition 2024).
```sh
cargo install --git https://github.com/Logic-py/python-check-updates
```
## Uninstall
```sh
pycu --uninstall
```
This removes the `pycu` binary and its configuration directory.
## Usage
Run in a directory that contains a `pyproject.toml` or `requirements.txt`:
```sh
pycu
```
Or point to a specific file:
```sh
pycu --file path/to/requirements.txt
```
### Options
| `--file <PATH>` | | Path to the dependency file (auto-detected if omitted) |
| `--upgrade` | `-u` | Rewrite the file in-place with updated constraints |
| `--target <LEVEL>` | `-t` | Only show `major`, `minor`, or `patch` bumps (default: `latest`) |
| `--json` | | Output results as JSON |
| `--concurrency <N>` | | Max concurrent PyPI requests (default: `10`) |
| `--set-color-scheme [SCHEME]` | | Preview all color schemes, or save one persistently |
| `--self-update` | | Update pycu itself to the latest release |
| `--uninstall` | | Remove pycu from your system |
| `--version` | | Print the version |
### Examples
```sh
# Check all dependencies
pycu
# Upgrade the file in-place
pycu --upgrade
# Only show minor-level updates
pycu --target minor
# Check a specific requirements file
pycu --file requirements-dev.txt
# Machine-readable output
pycu --json
```
### Color schemes
pycu ships with five built-in color schemes. Your preference is saved to
`~/.config/pycu/config.toml` (Linux/macOS) or `%APPDATA%\pycu\config.toml` (Windows) and
applied automatically on every run.
**Preview all schemes** (shown with live colored examples in your terminal):
```sh
pycu --set-color-scheme
```
**Set a scheme:**
```sh
pycu --set-color-scheme default # red / blue / green - GitHub-style SemVer severity
pycu --set-color-scheme okabe-ito # orange / blue / teal - color-blind safe (Okabe-Ito)
pycu --set-color-scheme traffic-light # red / yellow / green - classic CI model
pycu --set-color-scheme severity # purple / blue / gray - monitoring/observability style
pycu --set-color-scheme high-contrast # magenta / blue / yellow - maximum distinction
```
On first run, pycu will show the preview and prompt you to choose a scheme interactively.
### JSON output
```json
[
{
"name": "fastapi",
"current": ">=0.109.0",
"latest": "0.135.1"
}
]
```
## Supported formats
### pyproject.toml - PEP 621 / uv
```toml
[project]
dependencies = [
"fastapi>=0.109.0",
"pydantic>=1.10.0,<2.0.0",
]
[project.optional-dependencies]
dev = [
"pytest~=7.3.0",
]
[dependency-groups]
dev = [
"mypy>=0.19.1,<2.0.0",
]
```
### pyproject.toml - Poetry
```toml
[tool.poetry.dependencies]
fastapi = "^0.109.0"
[tool.poetry.group.dev.dependencies]
pytest = "~7.3.0"
```
### requirements.txt
```text
fastapi>=0.109.0
pydantic>=1.10.0,<2.0.0
pytest~=7.3.0 # dev
```
## Roadmap
- **Private registry support** - planned support for checking dependencies hosted on private PyPI-compatible
registries (e.g. Artifact Registry, etc.)
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md).
## Security
See [SECURITY.md](SECURITY.md).
## License
Licensed under either of [MIT](LICENSE-MIT) or [Apache-2.0](LICENSE-APACHE) at your option.