qlty-check

Qlty Code Quality

Universal code quality tool supporting 70+ linters for 40+ languages via qlty CLI.

When to Use

• Check code for linting issues before commit/handoff
• Auto-fix formatting and style issues
• Calculate code metrics (complexity, duplication)
• Find code smells

Quick Reference

# Check changed files with auto-fix
uv run python -m runtime.harness scripts/qlty_check.py --fix

# Check all files
uv run python -m runtime.harness scripts/qlty_check.py --all

# Format files
uv run python -m runtime.harness scripts/qlty_check.py --fmt

# Get metrics
uv run python -m runtime.harness scripts/qlty_check.py --metrics

# Find code smells
uv run python -m runtime.harness scripts/qlty_check.py --smells

Parameters

Parameter	Description
--check	Run linters (default)
--fix	Auto-fix issues
--all	Process all files, not just changed
--fmt	Format files instead
--metrics	Calculate code metrics
--smells	Find code smells
--paths	Specific files/directories
--level	Min issue level: note/low/medium/high
--cwd	Working directory
--init	Initialize qlty in a repo
--plugins	List available plugins

Common Workflows

After Implementation

# Auto-fix what's possible, see what remains
uv run python -m runtime.harness scripts/qlty_check.py --fix

Quality Report

# Get metrics for changed code
uv run python -m runtime.harness scripts/qlty_check.py --metrics

# Find complexity hotspots
uv run python -m runtime.harness scripts/qlty_check.py --smells

Initialize in New Repo

uv run python -m runtime.harness scripts/qlty_check.py --init --cwd /path/to/repo

Direct CLI (if qlty installed)

# Check changed files
qlty check

# Auto-fix
qlty check --fix

# JSON output
qlty check --json

# Format
qlty fmt

Requirements

• qlty CLI: https://github.com/qltysh/qlty
• MCP server: servers/qlty/server.py wraps CLI
• Config: .qlty/qlty.toml in repo (run qlty init first)

vs Other Tools

Tool	Use Case
qlty	Unified linting, formatting, metrics for any language
ast-grep	Structural code patterns and refactoring
morph	Fast text search