Jq Json Processor

Process, filter, and transform JSON data using jq - the lightweight and flexible command-line JSON processor.

Security Scan

The skill is an instruction-only helper for using the jq command-line JSON processor and its requirements and instructions are consistent with that purpose.

Purpose & Capability

Name, description, and SKILL.md all describe using jq to process JSON. The SKILL.md metadata declares the jq binary and provides brew/apt install hints, which are appropriate and proportional for this purpose.

Instruction Scope

Runtime instructions are concrete jq examples and common workflows (reading files, piping curl output, writing temp files and moving them into place). They do not instruct the agent to read unrelated system files, access secrets, or exfiltrate data. Examples that call curl or modify files are expected for a CLI usage guide but do require normal user caution when run.

Install Mechanism

The skill is instruction-only (no install spec in the registry). The SKILL.md metadata suggests installing jq via well-known package managers (brew, apt), which is low-risk and standard practice.

Credentials

The skill requests no environment variables or credentials. Examples reference external HTTP endpoints via curl, which is expected for demonstrating jq on API responses but does not require any stored secrets from the agent.

Persistence & Privilege

The skill is not always-enabled and is user-invocable; model invocation remains allowed (the platform default). The skill does not request persistent system privileges or modify other skills or system-wide settings.

Assessment

This is a straightforward jq usage guide; it does not request credentials or install arbitrary code. Before using: ensure jq is installed from your OS package manager (brew/apt) or the official project, and be careful when running example commands that modify files (they use a temp file + mv pattern). When piping or fetching data from remote APIs (curl examples), avoid sending secrets or sensitive local files into commands unless you trust the endpoint.

Process, filter, and transform JSON data with jq.

Quick Examples

Basic filtering

# Extract a field
echo '{"name":"Alice","age":30}' | jq '.name'
# Output: "Alice"

# Multiple fields
echo '{"name":"Alice","age":30}' | jq '{name: .name, age: .age}'

# Array indexing
echo '[1,2,3,4,5]' | jq '.[2]'
# Output: 3

Working with arrays

# Map over array
echo '[{"name":"Alice"},{"name":"Bob"}]' | jq '.[].name'
# Output: "Alice" "Bob"

# Filter array
echo '[1,2,3,4,5]' | jq 'map(select(. > 2))'
# Output: [3,4,5]

# Length
echo '[1,2,3]' | jq 'length'
# Output: 3

Common operations

# Pretty print JSON
cat file.json | jq '.'

# Compact output
cat file.json | jq -c '.'

# Raw output (no quotes)
echo '{"name":"Alice"}' | jq -r '.name'
# Output: Alice

# Sort keys
echo '{"z":1,"a":2}' | jq -S '.'

Advanced filtering

# Select with conditions
jq '[.[] | select(.age > 25)]' people.json

# Group by
jq 'group_by(.category)' items.json

# Reduce
echo '[1,2,3,4,5]' | jq 'reduce .[] as $item (0; . + $item)'
# Output: 15

Working with files

# Read from file
jq '.users[0].name' users.json

# Multiple files
jq -s '.[0] * .[1]' file1.json file2.json

# Modify and save
jq '.version = "2.0"' package.json > package.json.tmp && mv package.json.tmp package.json

Common Use Cases

Extract specific fields from API response:

curl -s https://api.github.com/users/octocat | jq '{name: .name, repos: .public_repos, followers: .followers}'

Convert CSV-like data:

jq -r '.[] | [.name, .email, .age] | @csv' users.json

Debug API responses:

curl -s https://api.example.com/data | jq '.'

Tips

• Use -r for raw string output (removes quotes)
• Use -c for compact output (single line)
• Use -S to sort object keys
• Use --arg name value to pass variables
• Pipe multiple jq operations: jq '.a' | jq '.b'

Documentation

Full manual: https://jqlang.github.io/jq/manual/ Interactive tutorial: https://jqplay.org/