Moonshot released its 2.8-trillion-parameter model for anyone to download

Moonshot AI put the full weights of Kimi K3.1 Pro on Hugging Face on November 4, meeting the deadline it set at launch — 96 files totalling about 1.56 TB, with no access gate. The model card lists 2.8 trillion parameters in total, 104 billion active per answer, and a 1-million-token context window.

Moonshot's own numbers put it within a point of Anthropic's Claude Opus 5.5 on Terminal-Bench 4.0, the coding-agent test — 65.7% against 66.4% — at half the API price, $2 in and $10 out per million tokens. Those scores are the company's own and haven't been independently checked, and the model only works in thinking mode.

The open release comes with a deliberate cut: Moonshot says it stripped cyber-related data from training because the model's exploit-finding ability kept rising — the released version solved 81% of its in-house exploit benchmark versus 90.5% for the uncut version. The license is Moonshot's own, free for most uses, but model-as-a-service businesses taking in over $20 million a year need a separate deal first.