EvalGlass

Use case · Model switching

You switched the model. Did the product get better?

A new model or provider can lift one behavior and quietly drop another. Instead of eyeballing a few prompts, ask your coding agent to evaluate the switch against your project-specific checks and read the deltas — but only where the two runs are comparable.

Evaluate my AI application after the model switch. Show what improved and what regressed.
You Evaluate my AI application after the model switch. Show what improved and what regressed.
Your coding agent · Claude Code plugin Done. I compared the model-switch run to your last baseline on the checks you own. Retrieval faithfulness improved +0.07, tool selection stayed stable, and cost dropped 18% — but workflow-policy answers regressed −0.11. Deltas are shown only where the runs are comparable. The verdict is informational: no threshold is approved yet, so nothing gates CI.

What it checks

faithfulness · answer quality · tool use · latency · cost · refusal rate · workflow policy · edge cases. A delta is shown only when the two runs are typed comparable; if the dataset, prompt, or config also moved, EvalGlass reports not_comparable rather than a false regression.

The scorecard

model-switch run · vs. last baseline informational
Retrieval faithfulness0.91 +0.07
Tool selectionstable
Cost / 1k calls$2.4 −18%
Workflow-policy answers0.74 −0.11

Verdict informational — deltas are comparable, but no gate is approved. Illustrative example, not a measured result.

experimental Comparable is the floor, not the finish. On the epistemic core each metric carries a confidence interval and an effective sample size, and a paired delta counts as a regression only when its interval clears zero — otherwise it is within_noise. A small delta may be noise, not a real move; the interval is what tells the two apart.

What it will not claim

A green number is not “the new model is better.” It is “these checks moved this much, where the runs were comparable.” EvalGlass never edits your model or prompt, and nothing gates until you approve a threshold in your own config. No false green →

Ask your coding agent.

Evaluate my agentic app using EvalGlass.

Related

All use cases
every change moment
Scorecards
what each run hands back
Get the plugin
two commands in Claude Code
Docs
the detailed reference