jq — Command-Line JSON Processor

jq (v1.8.1) is installed at /opt/homebrew/bin/jq. It reads JSON from stdin or files, applies filters, and outputs transformed JSON. Prefer jq over writing custom scripts for JSON manipulation in shell pipelines.

Core Concepts

Filters and Pipes

Every jq program is a filter. Filters connect with | (pipe) and produce zero or more outputs. The . filter is identity (passes input through).

# Field access
echo '{"name":"Ada"}' | jq '.name'

# Nested access
echo '{"user":{"id":1}}' | jq '.user.id'