GPT-6 Astra
GPT-6 Astra tops Artificial Analysis's independent Terminal-Bench v4.0 run at 59.6% on xhigh and 59.1% on max, with Claude Fable 5.1 next at 55.1% and Opus 5 absent from the published top three. Vals.ai has it first on Terminal-Bench 2.1 too, at 87.3% ahead of GPT-5.6 Sol (85.8%), Fable 5.1 (85.0%) and Opus 5 (84.6%). It has no independent SWE-bench Verified run — Vals archived that board as saturated — and it lists at $10/$50 per million tokens, 2.5x GPT-5.6 Sol, so price the high-volume repo-scale batches carefully.
Challenger: Claude Opus 5 — Still the leader on Vals.ai's independent SWE-bench Verified run at 97.00%, against the 96.0% Anthropic self-reports in the Opus 5 system card, on a board Vals has now archived as saturated and never ran GPT-6 Astra on. On Vals' Terminal-Bench 2.1 it sits fourth at 84.6%, behind Astra, GPT-5.6 Sol and Claude Fable 5.1, and it does not appear in the published Terminal-Bench 4.0 top three.
vals.ai's Terminal-Bench 2.1 table now has Opus 5 fourth at 84.64%, behind GPT-6 Astra (87.27%), GPT-5.6 Sol (85.77%) and Claude Fable 5.1 (85.02%), and its own figure drops to 81.27% if you count its server-side fallbacks to Opus 4.8 on refused tasks as failures. The SWE-bench Verified lead is thin as well: DeepSeek V4 Pro (0813) sits second at 96.40% against 97.00%, as an open-weight model costing roughly $0.02 per task against $1.29 for Opus 5. Worth knowing that vals has since dropped SWE-bench Verified from its coding index altogether, calling the benchmark saturated, so lean on terminal and repo-scale evidence rather than that one number.