When using Japanese in AzureOpenAI, answers may not be displayed

[sasaki000]

When using Azure LLM, if you specify Japanese in the prompt, the answer may not be displayed.
The version of OpenAI-agents is Version: 0.0.14.

• The following code may return a blank answer.

import agents

model_name = 'gpt-4.1-mini'

custom_client = agents.AsyncOpenAI(
    api_key='xxxx',
    base_url='https://yyyy.openai.azure.com/openai/deployments/gpt-4.1-mini',
    default_headers={'api-key': 'xxxx'},
    default_query={'api-version': '2025-04-01-preview'},
)
agents.set_default_openai_client(client=custom_client, use_for_tracing=False)
agents.set_default_openai_api(api='chat_completions')  # Default Model
agents.set_tracing_disabled(disabled=True)  # Disable Trace

model = agents.OpenAIChatCompletionsModel(
    model=model_name,
    openai_client=custom_client,
)


agent = agents.Agent(
    name='Assistant',
    instructions='あなたは役に立つアシスタントです',
    # instructions='You are a helpful assistant',
    model=model,
    # model_settings=agents.ModelSettings(temperature=0.0),  # ←Setting this increases the frequency with which results are not displayed.
    # hooks=LoggingAgentHooks()
)

# For Jupyter notebooks with existing event loops
result = await agents.Runner.run(
    starting_agent=agent,
    input='プログラミングにおける、再帰について俳句を書いてください。'
    # input='Write a haiku about recursion in programming.'
)

# print('----')
print(result.final_output)
# print('----')

This sometimes occurs when the prompt is set to Japanese. It does not occur when the prompt is set to English.
The debug log is attached below.
Could this be because the content from LLM is null? Why is it null?

[2025-05-06 07:50:17 - openai.agents:90 - DEBUG] Tracing is disabled. Not creating trace Agent workflow
[2025-05-06 07:50:17 - openai.agents:90 - DEBUG] Setting current trace: no-op
[2025-05-06 07:50:17 - openai.agents:90 - DEBUG] Tracing is disabled. Not creating span <agents.tracing.span_data.AgentSpanData object at 0x7f751c227ed0>
[2025-05-06 07:50:17 - openai.agents:90 - DEBUG] Running agent Assistant (turn 1)
[2025-05-06 07:50:17 - openai.agents:90 - DEBUG] Tracing is disabled. Not creating span <agents.tracing.span_data.GenerationSpanData object at 0x7f751c21f6b0>
[2025-05-06 07:50:17 - openai.agents:90 - DEBUG] [
  {
    "content": "\u3042\u306a\u305f\u306f\u5f79\u306b\u7acb\u3064\u30a2\u30b7\u30b9\u30bf\u30f3\u30c8\u3067\u3059",
    "role": "system"
  },
  {
    "role": "user",
    "content": "\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306b\u304a\u3051\u308b\u3001\u518d\u5e30\u306b\u3064\u3044\u3066\u4ff3\u53e5\u3092\u66f8\u3044\u3066\u304f\u3060\u3055\u3044\u3002"
  }
]
Tools:
[]
Stream: False
Tool choice: NOT_GIVEN
Response format: NOT_GIVEN

[2025-05-06 07:50:17 - openai._base_client:90 - DEBUG] Request options: {'method': 'post', 'url': '/chat/completions', 'headers': {'User-Agent': 'Agents/Python 0.0.14'}, 'files': None, 'idempotency_key': 'stainless-python-retry-0ac5b9fb-f94b-474b-8652-bc053a2daaf7', 'json_data': {'messages': [{'content': 'あなたは役に立つアシスタントです', 'role': 'system'}, {'role': 'user', 'content': 'プログラミングにおける、再帰について俳句を書いてください。'}], 'model': 'gpt-4.1-mini', 'stream': False}}
[2025-05-06 07:50:17 - openai._base_client:90 - DEBUG] Sending HTTP Request: POST https://yyyy.openai.azure.com/openai/deployments/gpt-4.1-mini/chat/completions?api-version=2025-04-01-preview
[2025-05-06 07:50:18 - httpx:94 - INFO] HTTP Request: POST https://yyyy.openai.azure.com/openai/deployments/gpt-4.1-mini/chat/completions?api-version=2025-04-01-preview "HTTP/1.1 200 OK"
[2025-05-06 07:50:18 - openai._base_client:90 - DEBUG] HTTP Response: POST https://yyyy.openai.azure.com/openai/deployments/gpt-4.1-mini/chat/completions?api-version=2025-04-01-preview "200 OK" Headers({'content-length': '1086', 'content-type': 'application/json', 'apim-request-id': '909d22a1-2694-4147-8425-307754af658b', 'strict-transport-security': 'max-age=31536000; includeSubDomains; preload', 'x-content-type-options': 'nosniff', 'x-ms-region': 'East US 2', 'x-ratelimit-remaining-requests': '249', 'x-ratelimit-limit-requests': '250', 'x-ratelimit-remaining-tokens': '249347', 'x-ratelimit-limit-tokens': '250000', 'cmp-upstream-response-duration': '268', 'x-accel-buffering': 'no', 'x-ms-rai-invoked': 'true', 'x-envoy-upstream-service-time': '312', 'x-request-id': '04551af5-9cb9-4607-90c2-82ab2c72da32', 'ms-azureml-model-time': '310', 'x-ms-client-request-id': '909d22a1-2694-4147-8425-307754af658b', 'azureml-model-session': 'v20250415-5-168444713-5', 'x-ms-deployment-name': 'gpt-4.1-mini', 'date': 'Mon, 05 May 2025 22:50:18 GMT'})
[2025-05-06 07:50:18 - openai._base_client:90 - DEBUG] request_id: 04551af5-9cb9-4607-90c2-82ab2c72da32
[2025-05-06 07:50:18 - openai.agents:90 - DEBUG] LLM resp:
{
  "content": null,
  "refusal": null,
  "role": "assistant",
  "annotations": [],
  "audio": null,
  "function_call": null,
  "tool_calls": null
}

[2025-05-06 07:50:18 - openai.agents:90 - DEBUG] Resetting current trace

[pakrym-oai]

When you say "The following code may return a blank answer." do you mean sometimes you'll get the answer and sometimes empty result?

Can you run the sample with OPENAI_LOG=debug and confirm that the model output has empty content?

[sasaki000]

Thanks for your reply.
Yes, sometimes it returns an answer, sometimes it returns an empty result.
I ran the example with OPENAI_LOG=debug and added a log where the model output contains empty content.

[chmakhijani]

Hi @sasaki000

I've attempted to reproduce the issue multiple times but have been unable to do so. I reviewed the logs and compared the request headers between the reported failed request and my successful reproduction. The only notable difference I found was in the maxTokens value — the customer's request had "maxTokens": -1, while mine used maxTokens: 300.

It's possible that this was a transient issue, as I can no longer reproduce it on my end.

Could you please retry and let me know if the issue persists?

[sasaki000]

I checked again with version: 0.0.16 and this issue no longer reoccurs.
I am now getting the expected results correctly.
Thank you very much.