Claude Fable 5 is Anthropic's most capable widely released model, with exceptional performance across software engineering, vision, knowledge work, and scientific research. It maintains focus across millions of tokens and improves its own outputs using persistent, file-based memory, compressing long-running work into far fewer sessions. The model achieves state-of-the-art vision performance, extracting precise numbers from detailed scientific figures and rebuilding a web app's source code from screenshots alone. Fable 5 posts top scores on senior-level reasoning benchmarks and, in its research-grade form, consistently produces novel, compelling scientific hypotheses when paired with domain expertise. With a 1M token context window, the model excels at extensive codebases, lengthy contracts, and comprehensive research documentation. Built-in classifiers detect a narrow set of high-risk requests and hand them off to a more constrained model, a path that on average affects fewer than 5% of sessions.
Claude Fable 5 runs on 3 different routes through the Opper gateway. Compare residency, ZDR, and training posture at a glance β full data-handling detail per route below.
| Provider | Region | Zero data retention | Training | Input | Output |
|---|---|---|---|---|---|
| US | Enterprise | No | $10.00 | $50.00 | |
| Multi | Enterprise | No | $10.00 | $50.00 | |
| US | Enterprise | No | $10.00 | $50.00 |
Training posture across routes: No training on prompts by default.
Each route hosting Claude Fable 5 has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Independent benchmark scores β composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call Claude Fable 5 through the Opper gateway with one API key. Let your coding agent set it up, or call it directly β Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.
Copy this and paste it into your coding agent β Claude Code, Cursor, Codex, and more β 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-fable-5",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
