jq: JSON Data Extraction Tool
Always invoke jq skill to extract JSON fields - do not execute bash commands directly.
Use jq to extract specific fields from JSON files without loading entire file contents into context.
When to Use jq vs Read
Use jq when:
- •Need specific field(s) from structured data file
- •File is large (>50 lines) and only need subset
- •Querying nested structures
- •Filtering/transforming data
- •Saves 80-95% context vs reading entire file
Just use Read when:
- •File is small (<50 lines)
- •Need to understand overall structure
- •Making edits (need full context anyway)
Common File Types
JSON files where jq excels:
- •package.json, tsconfig.json
- •Lock files (package-lock.json, yarn.lock in JSON format)
- •API responses
- •Configuration files
Default Strategy
Invoke jq skill for extracting specific fields from JSON files efficiently. Use instead of reading entire files to save 80-95% context.
Common workflow: fd skill → jq skill → other skills (fzf, sd, bat) for extraction and transformation.
Quick Examples
bash
# Get version from package.json jq -r .version package.json # Get nested dependency version jq -r '.dependencies.react' package.json # List all dependencies jq -r '.dependencies | keys[]' package.json
Pipeline Combinations
- •jq | fzf: Interactive selection from JSON data
- •jq | sd: Transform JSON to other formats
- •jq | bat: View extracted JSON with syntax highlighting
Skill Combinations
For Discovery Phase
- •fd → jq: Find JSON config files and extract specific fields
- •ripgrep → jq: Find JSON usage patterns and extract values
- •extracting-code-structure → jq: Understand API structures before extraction
For Analysis Phase
- •jq → fzf: Interactive selection from structured data
- •jq → bat: View extracted data with syntax highlighting
- •jq → tokei: Extract statistics from JSON output
For Refactoring Phase
- •jq → sd: Transform JSON data to other formats
- •jq → yq: Convert JSON to YAML for different tools
- •jq → xargs: Use extracted values as command arguments
Multi-Skill Workflows
- •jq → yq → sd → bat: JSON to YAML transformation with preview
- •jq → fzf → xargs: Interactive selection and execution based on JSON data
- •fd → jq → ripgrep: Find config files, extract values, search usage
Common Integration Examples
bash
# Extract and select dependencies jq -r '.dependencies | keys[]' package.json | fzf --multi | xargs npm info # Get and filter package versions jq -r '.devDependencies | to_entries[] | "\(.key)@\(.value)"' package.json | fzf
Note: Choosing Between jq and yq
- •JSON files (package.json, tsconfig.json): Use
jq - •YAML files (docker-compose.yml, GitHub Actions): Use
yq
Detailed Reference
For comprehensive jq patterns, syntax, and examples, load jq guide when needing:
- •Array manipulation and filtering
- •Complex nested data extraction
- •Data transformation patterns
- •Real-world workflow examples
- •Error handling and edge cases
- •Core patterns (80% of use cases)
- •Real-world workflows
- •Advanced patterns
- •Pipe composition
- •Error handling
- •Integration with other tools