pycaniuse

Query caniuse.com from your shell.

🚀 Why this project exists

I wanted a fast way to check browser compatibility without leaving the terminal. When you are already coding in a shell, jumping to a browser for every feature lookup adds friction. pycaniuse keeps this workflow simple: type a query, get compatibility ranges immediately, and optionally open a richer interactive full-screen view.

🧠 How this project works

pycaniuse runs in two phases:

1. Search phase

• Requests https://caniuse.com/?search=<query>&static=1
• Parses candidate matches from HTML
• Selection behavior:
  • No matches: exits non-zero with a friendly message
  • One match: auto-selects
  • Exact slug match: auto-selects
  • Multiple matches:
    • Interactive TTY: keyboard selector
    • Non-interactive: deterministic first match with notice

2. Feature phase

• Requests https://caniuse.com/<slug>?static=1
• If non-200, retries once without static=1
• Parses feature metadata and support ranges
• Renders:
  • Basic mode (default): compact output for major browsers
  • Full mode (--full): full-screen interactive TUI with all browsers and detail tabs

The parser extracts:

• feature title
• spec URL and status (when available)
• global usage percentages (supported, partial, total)
• description text
• browser support blocks and range status/timeline details
• optional notes/resources/sub-features for full mode

📐 Requirements

• Python >=3.10,<4.0
• Network access to https://caniuse.com

📦 Installation

pip install pycaniuse

🧪 Usage

$ caniuse --help
Usage: caniuse [OPTIONS] QUERY...

  Query caniuse.com from the terminal.

Options:
  --full         Enable full-screen interactive mode.
  -v, --version  Show the version and exit.
  -h, --help     Show this message and exit.

Examples:

caniuse flexbox
caniuse "css grid"
caniuse flexbox-gap --full

Basic-mode status icons:

• ✅ supported
• ❌ not supported
• ◐ partial support
• ﹖ unknown

Full-mode controls:

• q / Esc: quit
• Left / Right or h / l: move selected browser
• Up / Down or k / j: scroll selected browser ranges
• Tab / Shift+Tab or ] / [: next/previous detail tab
• PgUp / PgDn: page browsers and scroll tab content
• Home / End: jump to top/bottom for active browser ranges and tab content

🛠️ Features

• Live caniuse.com HTML fetching and parsing (no vendored dataset)
• Two display modes:
  • Basic mode (compact output)
  • Full mode (interactive full-screen TUI)
• Resilient search parsing with primary selectors plus fallback heuristics
• Browser support ranges with status icons and note markers
• Parse warnings for partial/degraded HTML parse scenarios
• Clean, typed error handling for network/HTTP/content failures
• Defensive parser behavior to avoid hard crashes on missing optional sections

🧩 Project Structure

• caniuse/cli.py: command orchestration
• caniuse/http.py: HTTP fetches, retry, static fallback
• caniuse/parse_search.py: search page parser
• caniuse/parse_feature.py: feature page parser
• caniuse/render_basic.py: basic renderer
• caniuse/ui/select.py: interactive match selector
• caniuse/ui/fullscreen.py: full-screen renderer and key loop
• caniuse/util/html.py: selector/text/attribute helpers
• caniuse/util/text.py: formatting and parsing helpers

Core models:

• SearchMatch
• SupportRange
• BrowserSupportBlock
• FeatureBasic
• FeatureFull

🧪 Development

Setup:

uv sync --frozen
uv pip install -e .
uv run pre-commit install

Or:

make install

Common commands:

make check       # lockfile check + pre-commit hooks
make test        # tox matrix (py310-py313, excludes canary marker)
make test-local  # local pytest + HTML coverage report
make build       # build dist artifacts

Canary test (live caniuse.com HTML shape):

uv run pytest -m canary

🐳 Docker

docker build -t pycaniuse .
docker run --rm -it pycaniuse flexbox

🚢 Release Utilities

• make version
• make check-version
• make build
• make check-dist
• make publish-test
• make publish
• make tag

🐞 Debugging

Set:

PYCANIUSE_DEBUG=1

This enables debug logging hooks in HTML utility helpers.

🧾 Changelog

See CHANGELOG.md

⚠️ Limitations

• No local cache or offline dataset
• Runtime behavior depends on caniuse.com HTML structure
• Network access is required at runtime
• If caniuse.com layout changes significantly, some sections may parse partially

🙏 Credits

• justhtml, for HTML parsing
• httpx, for HTTP client behavior
• Click, for CLI ergonomics
• Rich, for terminal rendering and TUI primitives

📄 License

MIT