Released 55 days after Claude Opus 4.1 · All Anthropic releases
Claude Sonnet 4.5 is described by Anthropic as the best coding model in the world and its strongest model for building complex agents. It marks a large step in computer interaction, scoring 61.4% on OSWorld for real-world computer operations, up sharply from 42.2% in the previous version. Sonnet 4.5 reaches state-of-the-art results on SWE-bench Verified for real-world software engineering. It maintains focus on complex multi-step assignments for over 30 hours, with notable gains in reasoning and mathematical problem solving across multiple benchmarks. With a 200K token context window and support for tools, vision, and PDF processing, Sonnet 4.5 handles computer automation tasks like navigating websites, filling spreadsheets, and completing browser-based workflows. It is described as Anthropic's most aligned frontier model to that point, with reduced concerning behaviors.
Claude Sonnet 4.5 runs on 5 different routes through the Opper gateway. Compare residency, ZDR, and training posture at a glance — full data-handling detail per route below.
| Provider | Region | Zero data retention | Training | Input | Output |
|---|---|---|---|---|---|
| US | Not by default | No | $3.00 | $15.00 | |
| EU | Zero data retention | No | $3.30 | $16.50 | |
| EU | Not by default | No | $3.00 | $15.00 | |
| US | Not by default | No | $3.00 | $15.00 | |
| EU | Not by default | No | $3.30 | $16.50 |
Claude Sonnet 4.5 runs on 4 independently monitored routes through the Opper gateway. A direct integration leaves you on one of them, the gateway serves whichever is healthy.
Measured over the last 30 days from each provider's official status feed via StatusGator. Refreshed hourly. See uptime for every provider Opper monitors.
Each route hosting Claude Sonnet 4.5 has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention is not on by default — abuse monitoring. No training on customer data. US; SCCs; DPA available.
Zero data retention is on by default on Pay-as-you-go — no action required. No training on customer data. EU; DPA available.
Zero data retention is not on by default — abuse monitoring, 30-day retention. No training on customer data. EU; DPA available.
Zero data retention is not on by default — abuse monitoring. No training on customer data. US; SCCs; DPA available.
Zero data retention is not on by default — abuse monitoring. No training on customer data. EU; DPA available.
Independent benchmark scores — composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call Claude Sonnet 4.5 through the Opper gateway with one API key. Let your coding agent set it up, or call it directly — Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.
Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.ai/v3/compat",});const completion = await client.chat.completions.create({model: "anthropic/claude-sonnet-4-5",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
