SWE-1.7 vs. Hy3

SWE-1.7 is a frontier software engineering model from Cognition built for advanced coding agents and long-horizon development workflows. It is designed to deliver strong coding intelligence at a fraction of the cost of some leading frontier alternatives, improving the cost-performance balance for real software engineering work. The model is trained from a Kimi K2.7 base and further improved through Cognition’s reinforcement learning pipeline, showing that additional post-training can still produce major capability gains. SWE-1.7 is optimized for tasks such as bug fixing, feature implementation, code migrations, terminal-based workflows, multilingual software engineering, large codebase navigation, and end-to-end validation. It performs especially well on longer asynchronous tasks where an AI agent needs to gather context, inspect files, test hypotheses, make changes, and verify results over an extended period. Cognition trained the model with infrastructure improvements that preserve entropy, stabilize training, support multi-cluster reinforcement learning, and improve fault tolerance across large distributed runs. The training process also focused heavily on data quality, using automated execution tests, verifier quality checks, reward-hacking prevention, and task filtering to create stronger learning signals. SWE-1.7 includes self-compaction, allowing it to summarize its working state and continue long projects even when tasks exceed the raw context window. It also uses an alternating length penalty to encourage concise reasoning on easier tasks while maintaining deeper exploration when a problem requires it. In practice, the model tends to explore codebases carefully, read relevant files, search for hidden requirements, test edge cases, and experiment before deciding how to implement a fix. Available in Devin across web, desktop, and CLI via Cerebras, SWE-1.7 gives engineering teams a powerful model for running scalable, cost-efficient coding agents.

The Hy3 preview showcases Tencent Hy's latest and most sophisticated model within the Hy series, boasting an impressive 295 billion parameters arranged in a Mixture-of-Experts framework, with 21 billion parameters activated and a remarkable 3.8 billion allocated to the MTP layer, all while supporting a vast context window of up to 256,000 tokens. This innovative model marks a significant milestone as it utilizes Tencent Hy's newly enhanced infrastructure, which is specifically designed to improve its effectiveness in various practical applications such as complex reasoning, following directives, contextual learning, coding assignments, and overall inference skills. By blending swift and comprehensive cognitive processing, it can provide clear responses for basic questions while also allowing for detailed analysis of complex mathematical, programming, and logical problems. The model is engineered to demonstrate extensive capabilities in comprehending lengthy contexts, following instructions accurately, utilizing tools effectively, and executing agent workflows with precision, with evaluations performed not only against traditional benchmarks but also in realistic business and development scenarios. Additionally, its versatile design allows for effective adaptation across a wide array of situations, significantly expanding its potential for use in numerous applications, thus making it a vital tool in advancing the field.