Description

When using deepseek-v4-flash model with Hermes Agent, tool calls fail with the following error:

HTTP 400: The reasoning_content in the thinking mode must be passed back to the API

Root Cause

The deepseek-v4-flash model has thinking mode enabled by default. When the model makes a tool call, the API returns a reasoning_content field in the response. According to DeepSeek's API requirements, subsequent requests must include this reasoning_content to maintain conversation continuity.

However, Hermes currently does not handle the reasoning_content field from DeepSeek API responses, causing the tool call to fail on the next request.

Technical Details

• Model: deepseek-v4-flash
• Error Message: The reasoning_content in the thinking mode must be passed back to the API
• DeepSeek Docs: https://api-docs.deepseek.com/guides/thinking_mode