jq: JSON Data Extraction Tool

Always invoke querying-json 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 querying-json skill for extracting specific fields from JSON files efficiently. Use instead of reading entire files to save 80-95% context.

Common workflow: finding-files skill → querying-json skill → other skills (fuzzy-selecting, replacing-text, viewing-files) for extraction and transformation.

Quick Examples

# 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

• querying-json | fuzzy-selecting: Interactive selection from JSON data
• querying-json | replacing-text: Transform JSON to other formats
• querying-json | viewing-files: View extracted JSON with syntax highlighting

Skill Combinations

For Discovery Phase

• finding-files → querying-json: Find JSON config files and extract specific fields
• searching-text → querying-json: Find JSON usage patterns and extract values
• extracting-code-structure → querying-json: Understand API structures before extraction

For Analysis Phase

• querying-json → fuzzy-selecting: Interactive selection from structured data
• querying-json → viewing-files: View extracted data with syntax highlighting
• querying-json → analyzing-code: Extract statistics from JSON output

For Refactoring Phase

• querying-json → replacing-text: Transform JSON data to other formats
• querying-json → querying-yaml: Convert JSON to YAML for different tools
• querying-json → xargs: Use extracted values as command arguments

Multi-Skill Workflows

• querying-json → querying-yaml → replacing-text → viewing-files: JSON to YAML transformation with preview
• querying-json → fuzzy-selecting → xargs: Interactive selection and execution based on JSON data
• finding-files → querying-json → searching-text: Find config files, extract values, search usage

Common Integration Examples

# 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