Kimi K3 vs Claude Sonnet 5.5

Side-by-Side API Pricing & Specs

Live per-million-token pricing served through Newton’s unified OpenAI-compatible gateway.

Real-World Engineering Workload Cost

Estimated spend for typical coding and autonomous agent workloads based on published per-token rates:

When to Route to Kimi K3 vs Claude Sonnet 5.5

Because Newton’s exposes both kimi-k3 and claude-sonnet-5-5 behind the same API key and base URL, engineering teams frequently combine both models in the same workflow:

• Primary Planning & ArchitectureKimi K3 (kimi-k3)
• High-Volume Execution & VerificationClaude Sonnet 5.5 (claude-sonnet-5-5)
• Interactive Cost SimulatorOpen Token Calculator →

Switch Between Both Models With One API Key

Point the official OpenAI SDK, Cursor, or Claude Code at https://newtons.dev/api/v1 and swap the model string on demand:

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.NEWTONS_API_KEY,
  baseURL: "https://newtons.dev/api/v1",
});

// Switch between Kimi K3 and Claude Sonnet 5.5 with 1 line:
const response = await client.chat.completions.create({
  model: "kimi-k3", // or "claude-sonnet-5-5"
  messages: [{ role: "user", content: "Compare architecture trade-offs." }],
});

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