Getting Started

Prerequisites

• Crystal >= 1.19.1

Installation

Add the dependency to your shard.yml:

dependencies:
  spdx:
    github: hahwul/spdx.cr

Run shards install to fetch the library.

Your First License Expression

require "spdx"

# Parse a license expression
ast = Spdx.parse("MIT AND Apache-2.0")
puts ast  # => MIT AND Apache-2.0

# Check validity
puts Spdx.valid_expression?("MIT OR GPL-2.0-only")  # => true
puts Spdx.valid_expression?("AND")                   # => false

Looking Up Licenses

require "spdx"

lic = Spdx.find_license("Apache-2.0")
puts lic.name          # => "Apache License 2.0"
puts lic.osi_approved? # => true
puts lic.fsf_libre?    # => true

# Case-insensitive lookup
puts Spdx.license?("mit")  # => true

CLI Tool

spdx.cr also provides a command-line tool. Build it with:

crystal build src/cli.cr -o bin/spdx

Then use it:

./bin/spdx expression parse "MIT AND Apache-2.0"
./bin/spdx license info MIT
./bin/spdx license list --osi

What is SPDX?

SPDX (Software Package Data Exchange) is an open standard for communicating software bill of materials (SBOM) information, including components, licenses, copyrights, and security references.

An SPDX license expression combines license identifiers with operators:

Next Steps

• License Expressions -- Parsing, validating, and formatting expressions
• License List -- Querying the embedded license database
• Documents -- Working with SPDX 2.3 documents