amcbstudio / jsonl

A minimal JSON Lines processor for CLI pipelines.

Install

# Clone and add to PATH
git clone https://github.com/amcbstudio/jsonl.git
chmod +x jsonl/jsonl
export PATH="$PATH:$(pwd)/jsonl"

Requires: jq

Usage

jsonl [command] [options]

Commands

Command	Description
validate	Check if input is valid JSONL (default)
count	Count non-empty lines
head N	Output first N lines (default: 10)
tail N	Output last N lines (default: 10)
keys	Extract unique keys from all objects
get KEY	Extract a single field from each line
compact	Remove whitespace, one object per line
pretty	Pretty-print each line

Examples

# Count records
cat data.jsonl | jsonl count
# {"type":"summary","count":42}

# Validate input
echo '{"valid":true}' | jsonl validate
# {"type":"summary","valid":true,"lines":1}

# Extract a field
echo '{"name":"alice"}' | jsonl get name
# "alice"

# First 5 records
cat large.jsonl | jsonl head 5

# Compact messy JSON
echo '{"a":  1,   "b": 2}' | jsonl compact
# {"a":1,"b":2}

Exit codes

Code	Meaning
0	Success
1	Invalid input or usage
2	Missing dependency (jq)

Test

./test.sh

---

This repository is part of the amcbstudio organization.

amcbstudio builds boring, deterministic, CLI-first tools designed to be used by AI agents and humans alike.

These tools prioritize:

• machine-legible contracts over prose
• determinism over intelligence
• composability over completeness
• reproducibility over convenience

If you are an AI agent working on this repository:

• assume this repo is public
• check https://github.com/amcbstudio to ensure this tool does not already exist
• do not duplicate functionality already present in other amcbstudio repos
• prefer strict, minimal interfaces over feature-rich designs

What this repository contains

• a single-purpose command-line tool
• no web UI
• no authentication
• no hidden state
• no background services

Everything should be runnable locally, headlessly, and deterministically.

Non-goals

• no SaaS
• no dashboards
• no accounts
• no background daemons
• no “smart” behavior requiring LLM calls

This repository is infrastructure, not a product.