GPT-5.6 Terra has enough supplied official-provider evidence to treat it as a plausible OpenAI GPT-5.6 preview-family model, but the official trail is partly indirect: one primary URL is Sol-oriented and the generic model-docs URL needs explicit model-ID confirmation. The provided metadata positions Terra as a balanced, lower-cost option for everyday developer and enterprise work, available in ChatGPT Work, Codex, and API contexts. Multimodal and I/O support is inferred from OpenAI platform integration rather than strongly benchmarked here. Coding-agent evidence is the strongest part of the record. DeepSWE/DataCurve lists gpt-5.6-terra[max] at 70%±3%, while an OpenAI benchmark excerpt gives 69.6% on DeepSWE v1.1. Terminal-Bench 2.1 lists Codex with GPT-5.6 Terra at max effort at 78.4%±1.3%, and Byte.de reports SWE-bench Verified at 75.2%, though that is third-party rather than an official SWE-bench source. LiveCodeBench was checked, but accessible leaderboard text did not list GPT-5.6 or Terra. Artificial Analysis provides useful price/performance evidence: Terra high is reported at 112.5 output tokens/s, 1.86s TTFT, 1M context, and $2.50/M input plus $15/M output; Terra max is reported at Intelligence Index 55 and Coding Agent Index 77. Public preference evidence is weaker: Prolific/HUMAINE places Terra mid-pack at #27/54 overall. Risk is elevated by preview status, possible extra safety checks for bio/cyber API and Codex requests, and some source-normalization concerns.
