# What are evals?

> Evals are repeatable tests that score an AI system's output against fixed examples, run before release and after every change.

Source: https://meshin.co/glossary/evals
Updated: 2026-10-02

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## Why it comes up

A security reviewer or a technical board member asks the same question they would of any release process. What stops a bad change from reaching customers? For a normal codebase, the answer is a test suite. For an AI feature, the honest answer is either an eval suite or "we check by hand." That second answer does not hold up once a product has more than a couple of prompts.

## What to do about it

Write down twenty to fifty real cases the system must handle correctly. Draw them from actual support tickets or usage, not invented examples, and include a few you know are hard. Score each case automatically where you can, and by a human reviewer where you cannot. Track the pass rate over time rather than treating one run as final. Run the suite before every prompt or model change ships.