[BUG CLIENT]: issue with agents+function calling (Not the same number of function calls and responses)

[fjtheknight]

Python -VV

Python 3.10.2 (tags/v3.10.2:a58ebcc, Jan 17 2022, 14:12:15) [MSC v.1929 64 bit (AMD64)]

Pip Freeze

annotated-types==0.7.0
anyio==4.9.0
certifi==2025.4.26
eval_type_backport==0.2.2   
exceptiongroup==1.3.0       
h11==0.16.0
httpcore==1.0.9
httpx==0.28.1
idna==3.10
mistralai==1.8.1
pydantic==2.11.5
pydantic_core==2.33.2       
python-dateutil==2.9.0.post0
six==1.17.0
sniffio==1.3.1
typing-inspection==0.4.1    
typing_extensions==4.14.0

Reproduction Steps

i am having issues with function calling from within agents. My workflow is as follows:

• user starts conversation with agent
• response is added to history then analysed
• if function call, execute function and add result to history and start conversation again
• now i get this error:
  [ERROR] API error occurred: Status 400 {"object":"Error","message":"Not the same number of function calls and responses","type":"invalid_request_error","code":3230}

example code:

api_history = [
  {
    "role": "user",
    "content": "i found a stray dog. the dog is white with a blue collar. it was found at 55 flower avenue. my email is test@email.com"
  },
  {
    "role": "assistant",
    "content": "",
    "tool_call_id": "eKp7ETcvQ",
    "name": "submit_animal_found_report",
    "result": ""
  },
  {
    "role": "tool",
    "content": {
      "status": "success",
      "report_id": "03075",
      "message": "Animal control has been notified. They may contact you for details."
    },
    "tool_call_id": "eKp7ETcvQ",
    "name": "submit_animal_found_report",
    "result": {
      "status": "success",
      "report_id": "FOUND-03075d",
      "message": "Animal control has been notified. They may contact you for details."
    }
  }
]

response = client.beta.conversations.start(
    agent_id=self.current_agent_id,
    inputs=api_history,
    store=False,
    handoff_execution="client"
)

not sure how number of function calls and responses are calculated. In ts client, I add toolcalls to assistant message and it works

{
    id: string;
    function: {
        name: string;
        arguments: string;
    };
}[]

but python sdk doesn't accept additional fields like tool_calls.

Everytime I run client.beta.conversations.start(...) because I am not saving converstation on the cloud so can't use conversations.update(...). It works except for when I add function call.

Thank you!

Expected Behavior

agent continues conversation normally

Additional Context

No response

Suggested Solutions

No response