RuntimeVault captures the full runtime state the instant an error fires — stack, variables, network, DOM — and hands it to Claude Code, Cursor, or any MCP-compatible agent. No more debugging from a bare stack trace. Free plan forever. How it works: 1. Install SDK (2 lines) 2. Error fires → snapshot captured 3. Run `rv replay snap_id` → local environment restored What makes it different from Sentry/LogRocket: we don't just show you what happened — we let you replay the exact state locally.