Turn approved specs into long-running autonomous implementation. A minimal, adaptable SDD harness with Agent Skills for Claude Code, Codex, Cursor, Copilot, Windsurf, OpenCode, Gemini CLI, and Antigravity.

AI agents can now write 99% of the code. This changes what it means to be a developer. Our role shifts to knowing "what good looks like". To do that, we need completely new developer tools. Tendril is what replaces your IDE in an agentic era.