GPT-5.6 Sol has strong official-provider support in the supplied evidence: OpenAI docs and product pages identify it as a flagship GPT-5.6 model, with API availability, a 1.05M-token context window, 128k max output tokens, prompt caching, persisted reasoning, tool calling, multi-agent beta, and safety-system-card coverage. Pricing is also clear in the cited metadata at $5/M input, $30/M output, and $0.50/M cached input, though this is high versus many alternatives. Coding and agentic evidence is the strongest part of the record. DeepSWE/DataCurve lists gpt-5.6-sol[max] at 73%±3%, second behind Claude Opus 5[max], while OpenAI reports 72.7%. SWE-bench evidence from OpenLM.ai and LLM Boss reports 96.2 on SWE-bench Verified, but these are secondary leaderboard sources and should not be over-weighted as official SWE-bench publication evidence. Artificial Analysis reports a Coding Agent Index lead at 80 and Intelligence Index figures of 54 medium / 59 max. Public preference and performance evidence is positive but mixed in quality. Arena.ai/LMArena-derived sources place GPT 5.6 Sol xHigh at rank 2 with about 10.1% net improvement across many sessions. Artificial Analysis reports 63.8 tokens/s and 4.39s TTFT for medium, suggesting usable but not exceptional latency. LiveCodeBench was checked and did not list GPT-5.6/Sol. Terminal-Bench/Aider-specific benchmark results were not provided; GitHub/OpenAI only supports general developer signal, not benchmark performance.
