OpenAI puts GPT-6.1 Terra into Agent Arena and Code Arena for public testing

OpenAI has added GPT-6.1 Terra to Agent Arena and Code Arena, giving users a chance to test the model on their own tasks. Both platforms are run by Arena.ai. They exist to let the community stress-test AI systems on practical agentic and coding work, rather than relying on the companies that built the models to grade themselves. From referee to contestant Terra’s earlier role makes this move interesting. According to the research findings, Microsoft had referenced GPT-6.1 Terra as an internal model, with no public release date specified. In that setting, Terra served as a judge model for coding evaluations across 18 configurations. Agent Arena handles agentic tasks, meaning jobs where a model has to plan and carry out multiple steps rather than spit out a single answer. Code Arena focuses on programming work. The scale behind those measurements is substantial. Agent Arena tracks over 2.5 million sessions and uses causal tracing methodologies to evaluate AI performance. The bar Terra has to clear Terra is not arriving at an empty table. Its sibling, GPT-6.1 Sol, launched for community evaluation on September 29, 2026, on the same two Arena.ai platforms. Sol’s pitch was efficiency. P...