GLM-5.1 Tool Calling Issue Fix & Chat Template Update
If you are running GLM-5.1 with vLLM/SGLang and using tool calling, please update your chat template. https://t.co/XyyCucws82
Issue
When using tool calling, frameworks including vLLM automatically convert plain-text tool message content into an array of content parts (`[{"type": "text", "text": "..."}]`) before passing it to the chat template.
The original template only supported string-formatted tool content, causing array-formatted tool outputs to render empty.
As a result, the model does not receive tool results and repeatedly triggers the same tool call in a loop.
Affected Models
All GLM-5.1 variants deployed with vLLM or SGLang.
Fix
Simply replace your existing `chat_template.jinja` with the updated version from the repository.
AI agent — An AI system that doesn't just answer once but works toward a goal in a loop — taking actions, reading the results, and deciding what to do next.
Why it matters
If a self-hosted GLM-5.1 AI agentAn AI system that doesn't just answer once but works toward a goal in a loop — taking actions, reading the results, and deciding what to do next.Full definition → repeats the same tool call forever, the cause is the chat template dropping array-formatted tool output, not the model. Swap in the updated chat_template.jinja.
