jq

name	jq
description	Expert jq usage for JSON querying, filtering, transformation, and pipeline integration. Practical patterns for real shell workflows.
category	development
risk	safe
source	community
date_added	2026-03-28
author	kostakost2
tags	["jq","json","shell","cli","data-transformation","bash"]
tools	["claude","cursor","gemini"]

jq — JSON Querying and Transformation

Overview

jq is the standard CLI tool for querying and reshaping JSON. This skill covers practical, expert-level usage: filtering deeply nested data, transforming structures, aggregating values, and composing jq into shell pipelines. Every example is copy-paste ready for real workflows.

When to Use This Skill

• Use when parsing JSON output from APIs, CLI tools (AWS, GitHub, kubectl, docker), or log files
• Use when transforming JSON structure (rename keys, flatten arrays, group records)
• Use when the user needs jq inside a bash script or one-liner
• Use when explaining what a complex jq expression does

How It Works

jq takes a filter expression and applies it to JSON input. Filters compose with pipes (|), and jq handles arrays, objects, strings, numbers, booleans, and null natively.

Basic Selection

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

# Nested access
echo '{"user":{"email":"[e-mail]"}}' | jq '.user.email'

# Array index
echo '[10, 20, 30]' | jq '.[1]'
# 20

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

# All array elements
echo '[{"id":1},{"id":2}]' | jq '.[]'

Filtering with select

# Keep only matching elements
echo '[{"role":"admin"},{"role":"user"},{"role":"admin"}]' \
  | jq '[.[] | select(.role == "admin")]'


curl -s https://api.github.com/repos/owner/repo/issues \
  | jq 


jq 


jq