Glassbrain captures every step of your AI app as an interactive visual trace tree. Click any node, swap the input, replay instantly without redeploying. Snapshot mode stores deterministic replays. Live mode hits your actual stack. Auto-generated fix suggestions reference exact trace data with one-click copy. Diff view shows exactly what changed. Shareable replay links let your team debug together. Works with OpenAI and Anthropic. Two lines of code to integrate. Free tier: 1K traces/month.