Moonshot AI launches Kimi K3.1 Pro, closing in on Claude Opus 5.5 in coding performance

Chinese AI startup Moonshot AI has launched Kimi K3.1 Pro, its latest AI model featuring a one million token context window and improved capabilities across coding, 3D development, financial research and autonomous AI agents. The company said Kimi K3.1 Pro scored 65.7% on Terminal Bench 4.0, a benchmark evaluating AI agents on real programming tasks, approaching Anthropic’s Claude Opus 5.5 at 66.4% and surpassing OpenAI’s GPT 6 Astra at 58.2%. The model is built on Kimi K3 with additional training focused on improving complex reasoning and the ability to complete tasks requiring multiple steps and tools. Moonshot also introduced Kimi K3.1 Pro Highspeed, a variant designed to deliver responses two to three times faster than the standard model. Both versions are available through Kimi.ai, Kimi Work, Kimi Code and the company’s API, with full model weights scheduled for release by November 4. Kimi K3.1 Pro improves long horizon coding capabilities Moonshot reported that Kimi K3.1 Pro scored 61.2% on Kimi Code Bench 3.0 Long horizon, an internal benchmark measuring AI agents’ ability to complete complex programming tasks involving multiple steps, tool use and extended problem solving. ...