Kuaishou's KwaiKAT Team releases KAT-Coder-V2.5 agentic coding model

The KwaiKAT Team at Kuaishou has introduced KAT-Coder-V2.5, a coding model trained to operate inside real, executable repositories rather than emit single-turn code. The served model is available through StreamLake, and an open-weight variant called KAT-Coder-V2.5-Dev was released on Hugging Face under the Apache-2.0 license. The team built over 100,000 verifiable repository environments spanning 12 languages by mining tasks from real pull requests and commits following the SWE-bench lineage. An AutoBuilder system constructs and verifies environments in isolated sandboxes, requiring more than 90% of expected tests to be collected and reproduce pass/fail outcomes across runs. Combining preconfigured base environments, build-system templates, and a retrievable library of distilled build recipes raised the construction success rate from 16.5% to 57.2%.