Kimi K3.1 Pro

• 🎯 Moonshot AI's flagship open-weight multimodal reasoning model
• 📏 Massive 1M-token context window
• 👁️ Vision input plus deep reasoning traces
• 🔧 Function calling and web search for agentic workflows
• 💻 Tuned for long-horizon coding, CAD code, and financial research
• 🌍 Open weights from Moonshot AI

Moonshot

Moonshot is an AI research lab known for developing the Kimi family of large language models. The organization has gained recognition for building capable reasoning-oriented models, with the Kimi line representing its flagship series of text generation…

Kimi K3.1 Pro sits at the top of Moonshot AI's open-weight lineup, a post-trained refinement of Kimi K3 that pairs multimodal input with extended reasoning and a one-million-token context window. Released in October 2026, it targets the hardest end of the assistant spectrum: tasks that unfold over many steps, span entire repositories or document sets, and require the model to call tools and search the web rather than answer from memory alone.

Within Moonshot's catalogue, the K-series splits by purpose. Kimi K3 Fast and K3.1 Pro Highspeed prioritise throughput, Kimi K2.7 Code is the coding-specialised branch, and the K2.x line covers general-purpose work. The Pro tier is the reasoning-heavy option, trading latency for depth on problems where a wrong first step is expensive.

Moonshot highlights long-horizon coding, agentic orchestration, financial research, and 3D modelling through generated CAD code as the model's core strengths. It is a strong fit for developers building autonomous agents, teams analysing very large document corpora, and anyone who needs a single model to read images, reason at length, and drive external tools in one session.