GLM-5.1

GLM-5.1 is positioned by Z.AI as a next-generation flagship aimed at agentic engineering, with a stated focus on long-horizon software tasks rather than one-shot answers. According to the official release post, the model is designed to stay productive across extended sessions, breaking complex problems into steps, running experiments, reading results, identifying blockers, and revising its strategy through repeated iteration. The release framing emphasizes that earlier models tend to plateau once they exhaust familiar techniques, while GLM-5.1 is built to remain effective over much longer task horizons, handling ambiguous problems with stronger judgment.

In benchmark terms, GLM-5.1 is reported as reaching state-of-the-art performance on SWE-Bench Pro with a score of 58.4, ahead of GLM-5 at 55.1, GPT-5.4 at 57.7, Opus 4.6 at 57.3, and Gemini 3.1 Pro at 54.2 on the same comparison chart. The same post also states that GLM-5.1 leads GLM-5 by a wide margin on NL2Repo repository generation and on Terminal-Bench 2.0 real-world terminal tasks, even though numeric values for those benchmarks are not included in the supplied excerpt. Practically, the model fits engineering workflows that need sustained, autonomous coding work — multi-step repository building, terminal-driven debugging, and security-oriented tasks — and is accessible through Z.AI's API, a coding-plan subscription, the zai-org/GLM-5 GitHub repository, and the zai-org/GLM-5.1 HuggingFace release.