@lean/cli

Command-line interface for the LEAN (Lightweight Efficient Adaptive Notation) data format.

Installation

npm install -g @lean-format/cli

Usage

Parse LEAN to JavaScript/JSON

# From file
lean parse data.lean

# From stdin
cat data.lean | lean parse

# Output to file
lean parse data.lean -o output.json

Format JavaScript/JSON to LEAN

# From file
lean format data.json

# From stdin
echo '{"name":"Alice","age":30}' | lean format

# Output to file
lean format data.json -o output.lean

Convert between formats

# LEAN to JSON
lean convert data.lean data.json

# JSON to LEAN
lean convert data.json data.lean

Validate LEAN files

lean validate data.lean

Watch mode (auto-convert on file changes)

lean watch data.lean

Initialize a sample LEAN file

lean init sample

Options

• -o, --output <file> - Output file path
• -p, --pretty - Pretty print JSON output
• -s, --strict - Enable strict mode validation
• -q, --quiet - Suppress non-error output

Examples

Parse and pipe to jq

cat config.lean | lean parse | jq '.database.host'

Format with custom output

lean format api-response.json -o config.lean

Watch and auto-convert

lean watch config.lean
# Every time config.lean changes, it converts to config.json

Features

• ✅ Unix-style stdin/stdout piping
• ✅ Cross-platform file watching with chokidar
• ✅ Row syntax support for tabular data
• ✅ Comprehensive validation
• ✅ Pretty printing options

Learn More

• LEAN Format Specification
• Report Issues
• Website

License

MIT © LEAN Format Team