claude-memory/graph/configurations/posttooluse-hook-auto-format-python-with-uvx-black-5ffd91.md

1.1 KiB

id type title tags importance confidence created updated
5ffd9141-9c39-4ea1-91c0-c10d9a4515e1 configuration PostToolUse hook: auto-format Python with uvx black
claude-code
hooks
python
black
uv
0.5 0.8 2026-02-15T03:39:18.028690+00:00 2026-02-15T03:39:18.028690+00:00

Set up a PostToolUse hook in ~/.claude/settings.json that auto-formats Python files with Black via uvx after every Edit/Write/MultiEdit.

Files: Hook script at ~/.claude/hooks/format-code.sh, config in ~/.claude/settings.json under hooks.PostToolUse.

Config: matcher 'Edit|Write|MultiEdit', command '/home/cal/.claude/hooks/format-code.sh', timeout 10.

Hook reads file path from stdin JSON (tool_input.file_path via jq), then dispatches by extension: .py runs uvx black --quiet, .js/.ts/.jsx/*.tsx runs prettier --write.

Key details: uvx runs Black without needing it as a project dependency (ephemeral env, cached after first run). Hook changes require session restart or /hooks review to take effect. matcher is a regex against tool name. First run downloads Black (~1.7MB), subsequent runs are near-instant.