Coding benchmark
VulcanBench CII v1 leaderboard
VulcanBench Coding Intelligence Index v1. Every model the catalog carries a published VulcanBench CII v1 value for, ranked by that value.
A post-cutoff software-engineering benchmark with hidden functional tests and regression guards, reported for vendor coding-agent harnesses.
VulcanBench CII v1 ranking
3 models with a published VulcanBench CII v1 value, ordered by that value, highest first. Models the source has not scored on this benchmark are not listed — they are unmeasured, not last.
| Rank | Model | Provider | Pass@1 with vendor coding-agent harnesses |
|---|---|---|---|
| 1 |  Claude Opus 5 | Anthropic | 96.4 |
| 2 | Claude Sonnet 5 | Anthropic | 89.2 |
| 3 |  GPT-5.6 Sol | OpenAI | 86.5 |
Evidence key: Observed
Rows are ordered by the value CII v1 frontier results published, highest first. The source does not state whether a higher value is the better result, so this page does not either: for a benchmark that measures a rate of failure, read the table from the bottom.