Anthropic launches Claude Fable 5.1 and expands government services

Anthropic has released Claude Fable 5.1, a new model designed for high-stakes knowledge work, coding, and complex, multi-stage research. The model features a 1-million-token context window and supports both text and image inputs. It includes “adaptive thinking” capabilities, allowing for proactive tool use, error recovery, and autonomous task planning.

In addition to the technical release, Anthropic is expanding its public-sector presence. Teresa Carlson, Anthropic’s Global Head of Public Sector, confirmed that Fable 5.1 is now available on Claude for Government. The model is also accessible via Amazon Bedrock in the U.S. government cloud. To comply with the EU AI Act, Anthropic has begun embedding content markings across generated text, code, and images.

These developments occur as Anthropic navigates ongoing legal disputes with the U.S. Department of Defense regarding usage restrictions and export controls. The company continues to work with the White House and the Five Eyes community, utilizing its Project Glasswing program to identify and patch cybersecurity vulnerabilities.