Enhancement: Show Reasoning (Thinking) for Gemini models

[KiGamji]

What features would you like to see added?

More details

Which components are impacted by your request?

No response

Pictures

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Code of Conduct

• I agree to follow this project's Code of Conduct

[watzon]

This would be nice to have for R1 as well. Just a toggle for "Show thinking" would be fantastic.

[webs7er]

I got the UI to show Deepseek's block in the UI.
Modify "MessageContent.tsx" (overwrite lines 130-136):

    // First try the standard :::thinking::: format
    let thinkingMatch = text.match(/:::thinking([\s\S]*?):::/);
    if (thinkingMatch) {
      return {
        thinkingContent: thinkingMatch[1].trim(),
        regularContent: text.replace(/:::thinking[\s\S]*?:::/, '').trim(),
      };
    }
    
    // Then try the <think> format used by DeepSeek R1 and similar models
    thinkingMatch = text.match(/<think>([\s\S]*?)<\/think>/);
    if (thinkingMatch) {
      return {
        thinkingContent: thinkingMatch[1].trim(),
        regularContent: text.replace(/<think>[\s\S]*?<\/think>/, '').trim(),
      };
    }
    
    // No thinking content found
    return {
      thinkingContent: '',
      regularContent: text,
    };
  }, [text]);

[insilications]

"By default, the Gemini API doesn't return thoughts in the response. To include thoughts in the response, you must set the include_thoughts field to true, as shown in the examples."

https://ai.google.dev/gemini-api/docs/thinking

[GTP95]

About Deepseek R1: I'm using it via OpenRouter. The interface has a button to show the thinking, but it disappears as soon as the model writes the final answer. It would be nice to have the possibility to leave the thinking visible.
Edit: It actually happened only for the first message in the chat, continuing the conversation it is now leaving the thinking process displayed on the page. Is this a known bug or should I open a separate issue?

[danny-avila]

I was looking to implement this, but it's not working at all on Google's end.

If you try this google colab, it will not output thoughts: https://colab.research.google.com/github/GoogleCloudPlatform/generative-ai/blob/main/gemini/getting-started/intro_gemini_2_0_flash_thinking_mode.ipynb#scrollTo=sG3_LKsWSD3A

[watzon]

Afaik Google doesn't expose the thinking via the API as of yet. It's only available in AI Studio.

[danny-avila]

they did at one point and then stopped, they even added a parameter to specify whether reasoning tokens should be included in the generation.

[taurit]

I tested how Gemini API behaves now, it seems to include thoughts when asked, at least for the recent gemini-2.5-flash-preview-04-17:)

[0wwafa]

where is this screenshot coming from?

[watzon]

Looks like Insomnia. They're showing the raw API call.

[xrellana]

Is there a way to add a button that toggles the thinking mode on or off in the chat? Some models have both modes available.

[abhishekag03-cb]

Hi, did we find out if there's a way to toggle this behaviour?