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Curtail

ReGrade®

Powered by patented NCAST technology

Field-level analysis that catches regressions in API behavior by comparing real traffic across software versions.

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How Curtail's ReGrade can help you

The same agent, the same bugs, a third of the time

We gave Claude Code the same codebase, the same two known bugs, and the same AI model. One session had ReGrade's structured differences to work from. The other had raw traffic replay. Here is what happened.

Ghost CMS v2.2.2 → v2.2.3 · Claude Opus 4.6 · 72 Requests · 3,328 Deltas

3.2×

Time Saved

3m 41s vs 11m 56s

1.8×

Cost Reduction

$2.02 vs $3.57

3.5×

Token Efficiency

1.2M vs 4.1M tokens

96%

Root-Cause Quality

of deltas traced to root cause

Without ReGradeWith ReGrade

Wall-Clock Time

Without ReGrade11m 56s
With ReGrade3m 41s−69%

Estimated Cost

Without ReGrade$3.57
With ReGrade$2.02−43%

Total Tokens

Without ReGrade4.1M
With ReGrade1.2M−71%

API Calls

Without ReGrade79
With ReGrade31−61%

Tool Calls

Without ReGrade48
With ReGrade16−67%

User Turns

Without ReGrade5
With ReGrade4−20%

With ReGrade's structured delta tools, Claude traced 96% of flagged deltas to a single root cause, using 71% fewer tokens and finishing 3.2× faster than raw replay.

Ghost CMS API benchmark: 72 requests, 3,328 deltas, 2 known bugs. Advantages compound with larger datasets.

Ask us how we can help

We will show you what ReGrade finds on a service you already run. Or start free: 10 replays and 100 MB every month, no credit card and no expiration.