GLM-5.1 is Z.AI's next-generation flagship model for agentic engineering, positioned to keep working effectively over long, multi-hour sessions rather than plateauing after early gains. It is trained with multi-turn supervised fine-tuning, reinforcement learning, and a process-quality evaluation framework aimed at improving stability, consistency, and tool use across extended tasks, with the goal of running autonomously for up to eight hours in a single pass. Compared with its predecessor GLM-5, it shows stronger engineering intelligence across autonomous planning, sustained execution, bug fixing, and strategy iteration.
In practice, the model is aimed at complex software engineering and repository-level development workflows. Its release benchmarks report a state-of-the-art score of 58.4 on SWE-Bench Pro for complex software engineering tasks, and a wide lead over GLM-5 on NL2Repo repo generation and Terminal-Bench 2.0 real-world terminal tasks. Weights are published openly under an MIT-style distribution on Hugging Face at zai-org/GLM-5.1, with code mirrored at github.com/zai-org/GLM-5, making GLM-5.1 a natural fit for teams building coding agents, deep debuggers, and other long-horizon developer tools that need durable judgment and iteration rather than one-shot answers.