openai/openai-python · error · ValueError

Expected a non-empty value for `assistant_id` but received {

Error message

Expected a non-empty value for `assistant_id` but received {assistant_id!r}

What it means

The (beta) Assistants retrieve method builds GET /assistants/{assistant_id} with the OpenAI-Beta: assistants=v2 header and validates assistant_id first. Empty or None raises ValueError client-side before the beta endpoint is hit.

Source

Thrown at src/openai/resources/beta/assistants.py:212

        extra_headers: Headers | None = None,
        extra_query: Query | None = None,
        extra_body: Body | None = None,
        timeout: float | httpx2.Timeout | None | NotGiven = not_given,
    ) -> Assistant:
        """
        Retrieves an assistant.

        Args:
          extra_headers: Send extra headers

          extra_query: Add additional query parameters to the request

          extra_body: Add additional JSON properties to the request

          timeout: Override the client-level default timeout for this request, in seconds
        """
        if not assistant_id:
            raise ValueError(f"Expected a non-empty value for `assistant_id` but received {assistant_id!r}")
        extra_headers = {"OpenAI-Beta": "assistants=v2", **(extra_headers or {})}
        return self._get(
            path_template("/assistants/{assistant_id}", assistant_id=assistant_id),
            options=make_request_options(
                extra_headers=extra_headers,
                extra_query=extra_query,
                extra_body=extra_body,
                timeout=timeout,
                security={"bearer_auth": True},
            ),
            cast_to=Assistant,
        )

    @typing_extensions.deprecated("deprecated")
    def update(
        self,
        assistant_id: str,
        *,

View on GitHub (pinned to 9917c6e28e)

Solutions

  1. Create an assistant via client.beta.assistants.create() and persist the returned id, then pass it to retrieve
  2. Validate assistant_id is non-empty before calling
  3. List assistants (client.beta.assistants.list()) to find existing ids

Example fix

# before
assistant = client.beta.assistants.retrieve(settings.ASSISTANT_ID)  # unset -> None
# after
assistant_id = os.environ['ASSISTANT_ID']
assistant = client.beta.assistants.retrieve(assistant_id)
Defensive patterns

Strategy: validation

Validate before calling

if not assistant_id:
    raise ValueError('assistant_id is required')
assistant = client.beta.assistants.retrieve(assistant_id)

Type guard

def valid_assistant_id(aid: object) -> bool:
    return isinstance(aid, str) and aid.startswith('asst_')

Try / catch

try:
    assistant = client.beta.assistants.retrieve(assistant_id)
except ValueError:
    logger.exception('assistant_id was empty')
    raise

Prevention

When it happens

Trigger: client.beta.assistants.retrieve('') or retrieve(None); assistant id from config or a DB row that is blank.

Common situations: Apps that store the assistant id at setup time but the save failed, leaving an empty string; migrating assistant configs between environments where the id was never populated.

Related errors

AI-assisted analysis of openai/openai-python@9917c6e28e (2026-08-28). Data as JSON: /api/errors/4117089a0e78c9a6. Report an issue: GitHub.