Your agent writes the code, and then something has to say whether it did what you asked. Usually that something is another model reading the diff and forming an opinion about it. Tiden captures your intent as requirements, versioned alongside the code, then checks every change against them using tests that actually ran in your environment, so what comes back is a pass or a fail rather than a second opinion. No model grades the diff. It works beside Claude Code, Cursor, Copilot and Codex, and it's built by the team behind Qase, the testing platform 2,000+ teams already run on.