Snapshot testing for AI agents.
Record what your agent does today. Get told when it silently changes.
Your agent returns 200 and looks fine. But a model update, a provider change, or a one-line prompt edit just made it skip a clarification, call the wrong tool, or quietly drop output quality. Your tests still pass. Your users notice before you do.
EvalView snapshots your agent's behavior — the tools it calls, in what order, with what output — and tells you the moment that behavior changes. Like Jest snapshots, but for tool-calling, multi-turn agents.
demo.mp4
↑ 30-second live demo — no API key needed
pip install evalviewevalview snapshot # Record your agent's current behavior as the baseline
evalview check # After any change, diff against the baselineThat's the whole loop. check returns one of:
✓ login-flow PASSED behavior matches baseline
⚠ refund-request TOOLS_CHANGED called a different tool, or in a different order
✗ billing-dispute REGRESSION score dropped — output quality fell