Estimated spend for typical coding and autonomous agent workloads based on published per-token rates:
Claude Opus 4 (20250514) · 10M In + 2M Out—Claude Opus 5 · 10M In + 2M Out$10.00Billing ModelPrepaid · $0 Hard Stop
When to Route to Claude Opus 4 (20250514) vs Claude Opus 5
Because Newton’s exposes both claude-opus-4-20250514 and claude-opus-5 behind the same API key and base URL, engineering teams frequently combine both models in the same workflow:
Primary Planning & ArchitectureClaude Opus 4 (20250514) (claude-opus-4-20250514)
High-Volume Execution & VerificationClaude Opus 5 (claude-opus-5)
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 Claude Opus 4 (20250514) and Claude Opus 5 with 1 line:
const response = await client.chat.completions.create({
model: "claude-opus-4-20250514", // or "claude-opus-5"
messages: [{ role: "user", content: "Compare architecture trade-offs." }],
});