Anthropic releases Sonnet 5 as Fable returns

Anthropic has launched Sonnet 5, the latest model in its midtier Claude line, as the company also prepares to bring Fable 5 and Mythos 5 back online after U.S. export controls were lifted. The release comes as Anthropic positions Sonnet 5 as its most capable Sonnet model yet, especially for coding, reasoning, and agentstyle tasks. According to Anthropic, Sonnet 5 can work with browsers and terminals, handle longer tasks, and bring more advanced agent behavior to a lowercost tier. The company said the model performs well on knowledge work benchmarks, though its cybersecurity results are weaker than Sonnet 4.6 because it was not specifically trained for those tasks. The model is available across Anthropic plans, and API pricing is set at $2 per million input tokens and $10 per million output tokens through Aug. 31, before rising to $3 and $15 after that date. The launch also comes alongside broader activity in the AI sector, including new developer tools and products from Google and Anthropic’s new sciencefocused workspace.