Anthropic released Claude Sonnet 4.5 on September 29, 2025. It is integrated into the Anthropic API, Amazon Bedrock, Google Cloud Vertex AI, and GitHub Copilot, with pricing consistent with the previous generation, and it utilizes the ASL-3 security framework. Key enhancements include:
- Coding Capabilities: Supports code generation, debugging, and managing large codebases. Its performance on SWE-Bench is significantly improved, capable of handling 75,000 lines of code.
- Agency and Autonomous Operation: Enhanced tool use and multi-agent coordination, capable of running autonomously for 30 continuous hours.
- Computer Use: Simulates human operations, supporting directory scanning and file editing, with a context window up to 1M tokens.
- Reasoning and Controllability: Improved instruction following, visual reasoning, and mathematical capabilities, with scores increased by 80–95% on GPQA Diamond, MMMU, and AIME 2025.
- Other Features: Supports image generation, voice chat, and local file management (e.g., Harmony), suitable for enterprise-level high-throughput tasks.
In conjunction with the model release, Anthropic also implemented a series of upgrades to Claude Code. Key enhancements include:
- Checkpoints: Allows users to save snapshots of their work progress and roll back to previous states.
- Claude Agent SDK: A new development toolkit that provides developers with the infrastructure and building blocks Anthropic uses internally to build cutting-edge products.
- VS Code Extension: A brand-new native extension for Visual Studio Code that seamlessly integrates Sonnet 4.5’s capabilities into the development environment.
- Context Management Tools: The Claude API introduces new context editing features and memory tools to effectively manage information outside the context window and clean up outdated tool history.
