Allow System Prompt be optional for LLM Node

[thiner]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

I tried to use the local deployed DeepSeek R1 distilled 32b model in workflow. Due to the special chat template of R1, the current LLM node settings is not compatible to make it work smoothly.

1. System prompt is required currently, but R1 does not support system prompt.
2. I tried leave the the system prompt empty, move the original system prompt to "user" input(see below screenshot), but the model will take the prompt as user input, ignore the real user questions. To make it work, I have to put real question in LLM configuration.

I would expect to see below enhancements:

1. Allow system prompt be optional, so R1 model can see the real user question.
2. R1 response contains the think steps wrapped in <think> tags. Please enhance the result render component, grey out( or maybe other style) the think steps.

2. Additional context or comments

No response

3. Can you help us with this feature?

• [ ] I am interested in contributing to this feature.

[dosubot[bot]]

Hi, @thiner. I'm Dosu, and I'm helping the Dify team manage their backlog. I'm marking this issue as stale.

Issue Summary:

• Enhancement request to make the system prompt optional for the LLM Node.
• Aimed to support the DeepSeek R1 model, which lacks system prompt support.
• Suggestions include improvements for handling real user questions and styling changes for better readability.
• No further comments or activity since the issue was opened.

Next Steps:

• Please confirm if this issue is still relevant to the latest version of the Dify repository by commenting here.
• If there is no further activity, this issue will be automatically closed in 15 days.

Thank you for your understanding and contribution!

[thiner]

I turns out it's my fault that I forgot to add user input in the chat flow. It's not an issue of Dify.

[dosubot[bot]]

Thank you for closing the issue, thiner! We appreciate your help in keeping the repository organized.