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 |