Chinese AI lab Zhipu AI releases GLM-5.2 with a stable 1-million-token context under the MIT license. On hours-long coding tasks, the open-source model trails Anthropic's Opus models by just a few percentage points.
Zhipu AI has unveiled GLM-5.2, positioning the model as a tool for so-called long-horizon tasks - coding jobs that stretch over hours and thousands of individual steps. To get there, the company expanded the context window to one million tokens and focused training on agentic coding scenarios like large-scale implementation, automated research, and complex debugging.
"A 1M context is easy to claim, but much harder to keep reliable under real engineering pressure," Zhipu AI writes in its blog post, because the model needs to maintain quality across long, unstructured coding agent sessions.
On long-horizon tasks, GLM-5.2 usually lands just behind Opus 4.8 but remains the strongest open model. | Image: Zhipu AI
Just one percentage point behind the latest Opus model
