yq
Extract specific fields from YAML files efficiently using qq instead of reading entire files, saving 80-95% context.
When & Why to Use This Skill
The yq Claude skill is a high-performance YAML query and extraction tool designed to optimize AI context management. By retrieving only specific fields instead of processing entire files, it reduces context window usage by 80-95%. This tool is essential for developers and DevOps engineers working with large configuration files, enabling efficient data transformation, filtering, and deep-nested querying without hitting token limits.
Use Cases
- Efficiently extracting specific service ports, volumes, or environment variables from large docker-compose.yml files.
- Retrieving specific job steps or secret references from complex GitHub Actions and CI/CD workflow configurations.
- Querying and inspecting nested resource limits, image tags, or metadata within massive Kubernetes (K8s) manifest files.
- Filtering structured YAML data to provide the AI agent with only the necessary parameters for debugging or architectural analysis.
- Automating the extraction of versioning and dependency information from configuration files to save token costs during large-scale code reviews.
| name | yq |
|---|---|
| description | Extract specific fields from YAML files efficiently using qq instead of reading entire files, saving 80-95% context. |
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
# 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:
- 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