Env Contract

Typed ENV contracts with validation and sample generation.

About

Env Contract lets you define required and optional environment variables with types, defaults, and descriptions. It validates values at boot time and provides a env-contract CLI to generate .env.sample output.

This is useful for services that need clear, enforceable configuration contracts and easy onboarding.

Use Cases

• Enforce required configuration at boot time
• Generate .env.sample files for onboarding and docs
• Prevent misconfigurations in multi-env deployments

Compatibility

• Ruby 3.0+

Elysium Arc Reliability Toolkit

Also check out these related gems:

• Cache Coalescer: https://github.com/Elysium-Arc/cache-coalescer
• Cache SWR: https://github.com/Elysium-Arc/cache-swr
• Faraday Hedge: https://github.com/Elysium-Arc/faraday-hedge
• Rack Idempotency Kit: https://github.com/Elysium-Arc/rack-idempotency-kit

Installation

# Gemfile

gem "env-contract"

Usage

EnvContract.define do
  required :DATABASE_URL, type: :string, desc: "Primary DB"
  optional :REDIS_URL, type: :string
  optional :RETRIES, type: :integer, default: 3
end

values = EnvContract.load!

Types

• :string
• :integer
• :float
• :boolean
• :json

CLI

Generate .env.sample:

env-contract > .env.sample

Rails

# config/application.rb
config.env_contract.validate_on_boot = true

Release

bundle exec rake release