# Yq

> Extract specific fields from YAML files efficiently using qq instead of reading entire files, saving 80-95% context.

- Skill: `majiayu000/yq` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add majiayu000/yq`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/yq/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/yq

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# yq: YAML Query and Extraction Tool

Use yq to extract specific fields from YAML files without reading entire file contents, saving 80-95% context usage.

## When to Use yq

**Use yq when:**
- Need specific field(s) from structured YAML file
- File is large (>50 lines) and only need subset of data
- Querying nested structures in YAML
- Filtering/transforming YAML data
- Working with docker-compose.yml, GitHub Actions workflows, K8s configs

**Just use Read when:**
- File is small (<50 lines)
- Need to understand overall structure
- Making edits (need full context anyway)

## Tool Selection

**JSON files** → Use `jq`
- Common: package.json, tsconfig.json, lock files, API responses

**YAML files** → Use `yq`
- Common: docker-compose.yml, GitHub Actions, CI/CD configs

Both tools extract exactly what you need in one command - massive context savings.

## Quick Examples

```bash
# Get version from package.json
jq -r .version package.json

# Get service ports from docker-compose
yq '.services.*.ports' docker-compose.yml
```

## Detailed Reference

For comprehensive yq patterns, syntax, and examples, load [yq guide](./reference/yq-guide.md):
- Core patterns (80% of use cases)
- Real-world workflows (Docker Compose, GitHub Actions, Kubernetes)
- Advanced patterns and edge case handling
- Output formats and pipe composition
- Best practices and integration with other tools