Kwaipilot KAT-Coder-Pro V2 Is Now Available in Puter.js

Puter.js now supports KAT-Coder-Pro V2, the flagship agentic coding model from Kwaipilot (Kuaishou's AI research division)—featuring a 256K token context window, Mixture-of-Experts architecture, and top-tier coding benchmarks.

What is KAT-Coder-Pro V2?

KAT-Coder-Pro V2 is Kwaipilot's latest and most capable coding model, released on March 27, 2026. It is built for enterprise-grade software engineering, SaaS integration, and agentic coding workflows.

Key highlights:

• 79.6% on SWE-Bench Verified — a major leap from V1's 73.4%, placing it among the top coding models globally
• 256K token context window — handle entire codebases and complex multi-file projects in a single prompt
• Mixture-of-Experts architecture — 72B active parameters for efficient, high-quality inference at ~109 tokens/second
• Web aesthetics generation — ranked #1 across all frontend aesthetics benchmarks for landing pages, slides, and data visualizations
• Tool use and function calling — designed for agentic workflows with multi-turn interaction support

KAT-Coder-Pro V2 uses a novel "Specialize-then-Unify" training paradigm, where five specialized expert domains (SWE, WebCoding, Terminal, WebSearch, General) are trained independently and then consolidated into a single model via on-policy distillation.

Examples

Code Generation

puter.ai.chat("Write a Python REST API with FastAPI that includes JWT authentication and CRUD operations",
  { model: 'kwaipilot/kat-coder-pro-v2' }
);

Agentic Debugging

puter.ai.chat([
  { role: "user", content: buggyCode + "\n\nThis function is returning incorrect results for edge cases. Identify the bug and provide a fix with explanation." }
], { model: 'kwaipilot/kat-coder-pro-v2' });

Streaming

const response = await puter.ai.chat(
  "Create a responsive landing page with modern CSS animations and a contact form",
  { model: 'kwaipilot/kat-coder-pro-v2', stream: true }
);

for await (const part of response) {
  puter.print(part?.text);
}

Get Started Now

Just add one library to your project:

// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';

Or add one script tag to your HTML:

<script src="https://js.puter.com/v2/"></script>

No API keys and no infrastructure setup. Start building with KAT-Coder-Pro V2 immediately.

Learn more:

• Free, Unlimited Kwaipilot Kat API
• Puter.js AI Documentation