Ruby Claude is a small, dependency-light, idiomatic Ruby wrapper around the Claude Code CLI in headless mode (claude -p). It lets Ruby programs talk to Claude using a Claude Pro/Max subscription for authentication instead of an Anthropic API key: by default it strips ANTHROPIC_API_KEY from the child process environment so the CLI falls back to the logged-in subscription credentials. Unofficial; uses a supported headless feature within the subscription's rate limits.