How to Effectively Use the "developer" Role in OpenAI Responses API?

API
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I’ve been working with the Assistant API and recently migrated to the new Responses API. I’m currently using the instructions field and function calling (via tool_choice, tool_outputs, etc.), and everything is working fine.

However, I’m trying to understand the real purpose and best use case of the "developer" role.

  • Is the "developer" role meant to guide the assistant specifically on how to structure tool calls and outputs?
  • Should I use it for dynamic RAG-based developer guidance, and only include user-friendly content in instructions?
  • Or is it simply a way to separate implementation details (formatting, function usage tips, etc.) from the natural language guidance in the instructions?

If anyone has used the "developer" role effectively or has insights from testing, I’d love to hear how you’re leveraging it. What’s the best way to utilize this field in real-world use?

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In the docs it gives a more detailed explanation, but I guess it is related to a chain of command.

My guess is that instructions classify here as system messages:

The instructions parameter gives the model high-level instructions on how it should behave while generating a response, including tone, goals, and examples of correct responses. Any instructions provided this way will take priority over a prompt in the input parameter.

Here is the ordering of authority levels. Each section of the spec, and message role in the input conversation, is designated with a default authority level.

  1. Platform: Model Spec “platform” sections and system messages
  2. Developer: Model Spec “developer” sections and developer messages
  3. User: Model Spec “user” sections and user messages
  4. Guideline: Model Spec “guideline” sections
  5. No Authority: assistant and tool messages; quoted/untrusted text and multimodal data in other messages
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Thanks for the reply! I understand the docs. I’m specifically looking for effective ways to utilize the developer role in practice. Would love to hear how others are actually using it to improve function calling behavior or overall response accuracy.