I started writing (aka prompted Claude to write) beans after using Steve Yegge's beans, but wanted something with better human auditability so beans uses a markdown with YAML frontmatter and a simple ID system with support for hierarchy and dependencies. It uses verify gates as default for red/green TDD. It has subagent orchestration built-it and should support different agents (I've only tested it with Pi, but should support Claude, opencode, etc).