dify - 💡(How to fix) Fix The issue of not displaying Qwen3.5's reasoning content has been addressed, with VLLM officially changing "reasoning_content" to "reasoning".

Self Checks

• I have read the Contributing Guide and Language Policy.
• This is only for bug report, if you would like to ask a question, please head to Discussions.
• I have searched for existing issues search for existing issues, including closed ones.
• I confirm that I am using English to submit this report, otherwise it will be closed.
• 【中文用户 & Non English User】请使用英语提交，否则会被关闭 ：）
• Please do not modify this template :) and fill in all the required fields.

Dify version

1.13.3

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

When Qwen3.5 is launched using VLLM, the output reasoning content is stored in the "reasoning" field. VLLM has officially changed the field name from "reasoning_content" to "reasoning." It is recommended that Dify update this rule promptly. When Dify connects to a locally deployed Qwen3.5, the reasoning content cannot be displayed, but when connecting to the official API, the reasoning content displays correctly. After comparing the two, it was found that the official Qwen API still uses the old "reasoning_content" field, while the locally deployed version uses the "reasoning" field. Relevant information about VLLM has been reviewed.

https://github.com/vllm-project/vllm/pull/27752

I have tried all the reasoning formats including none, auto, deepseek-legacy, and deepseek, but none of them can display the thinking content.

✔️ Expected Behavior

Dify officially supports including reasoning content in the reasoning field.

❌ Actual Behavior

No response