Introducing SWE-1.5: Our Fast Agent Model

Windsurf releases SWE-1.5, a frontier-size AI model with hundreds of billions of parameters optimized for software engineering tasks. The model achieves near state-of-the-art coding performance while delivering inference speeds up to 950 tokens per second through a partnership with Cerebras—6x faster than Haiku 4.5 and 13x faster than Sonnet 4.5. Trained on real-world coding scenarios with input from senior engineers, SWE-1.5 focuses on writing clean, maintainable code and integrates tightly with Windsurf's agent experience. The model excels at exploring large codebases, full-stack development, and infrastructure work, reducing task completion times from 20+ seconds to under 5 seconds.