[recipe, rollout] feat: enable gpt-oss training for tool agent add gpt-oss for retool recipe

[HJSang]

What does this PR do?

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• add the tool response parsing logic for gpt-oss models
• add training recipe for retool

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[gemini-code-assist]

Code Review

This pull request introduces support for gpt-oss models in the tool agent, including a new training recipe and logic for handling tool responses. The refactoring of tool response formatting into a shared utility is a good step towards code reuse. However, this change has led to a critical runtime bug in two files due to incorrect argument types being passed to the new utility function. I've provided specific comments and code suggestions to address these critical issues. Once these fixes are applied, the changes look solid.

[wuxibin89]

@HJSang Do you have any gpt-oss performance metrics on retool?

[HJSang]

@HJSang Do you have any gpt-oss performance metrics on retool?

I attached details to this issue: #3794.
Overall, we still see an issue for grad norm. It may be due to some inconsistency between inference and training or kernel issue. We will continue investigate.

[mirrorboat]

@HJSang self.tool_parser is NOT a string, thus the condition of the if statement here is always false.

[HJSang]

Good catch. Let me fix it.

…

On Tue, Oct 21, 2025 at 10:50 PM mirrorboat ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In verl/experimental/agent_loop/tool_agent_loop.py <#3837 (comment)>: > @@ -341,11 +344,25 @@ async def _handle_processing_tools_state(self, agent_data: AgentData) -> AgentSt model_inputs = self.processor(text=[raw_tool_response], images=current_images, return_tensors="pt") response_ids = model_inputs.pop("input_ids").squeeze(0).tolist() else: - response_ids = await self.loop.run_in_executor( - None, - lambda: self.tokenizer.apply_chat_template(add_messages, add_generation_prompt=True, tokenize=True), - ) - response_ids = response_ids[len(self.system_prompt) :] + if self.tool_parser == "gpt-oss": @HJSang <https://github.com/HJSang> self.tool_parser is NOT a string, thus the condition of the if statement here is always false. — Reply to this email directly, view it on GitHub <#3837 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AI3YZXRQ5APOQNBJQFIKK5L3Y4LJXAVCNFSM6AAAAACJW7OPBCVHI2DSMVQWIX3LMV43YUDVNRWFEZLROVSXG5CSMV3GSZLXHMZTGNRTG44TSMBRHA> . You are receiving this because you were mentioned.Message ID: ***@***.***>