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WTF is this error?

Paste any stack trace. Get the root cause, the fix, and the prevention.

Works with Node, Python, Ruby, Java, Go, Rust, Docker, Kubernetes, browser console — paste up to ~50 lines. We auto-refuse anything that looks like secrets.

Examples:
How this works
  • What you get: the most-likely cause + a copy-paste fix + a short explanation of why it happens. No filler, no "Great question!"
  • Languages: JavaScript / TypeScript, Python, Ruby, Java, Go, Rust, shell, Docker, Kubernetes, browser console.
  • Privacy: traces are stored hashed for analytics; the raw paste lives 90 days for anon, lifetime for signed-in users. We never train on your data.
  • Auto-redacted: we refuse the scan if your paste contains anything that looks like an API key, JWT, or private key — rotate immediately if we flag one.
  • Speed: typically <3 seconds on Claude Haiku 4.5. We don't upgrade to a bigger model unless you ask — that's what the Pro "deeper explanation with citations" mode is for.