openai/openai-python · error · ValueError

Expected a non-empty value for `file_id` but received {file_

Error message

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

What it means

The sync files retrieve method requires a non-empty `file_id` path parameter. The SDK validates it before GETting `/files/{file_id}` and raises ValueError when it is None or an empty string. This protects against malformed URLs and happens before any network activity.

Source

Thrown at src/openai/resources/files.py:181

        extra_headers: Headers | None = None,
        extra_query: Query | None = None,
        extra_body: Body | None = None,
        timeout: float | httpx2.Timeout | None | NotGiven = not_given,
    ) -> FileObject:
        """
        Returns information about a specific file.

        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 file_id:
            raise ValueError(f"Expected a non-empty value for `file_id` but received {file_id!r}")
        return self._get(
            path_template("/files/{file_id}", file_id=file_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=FileObject,
        )

    def list(
        self,
        *,
        after: str | Omit = omit,
        limit: int | Omit = omit,
        order: Literal["asc", "desc"] | Omit = omit,

View on GitHub (pinned to 9917c6e28e)

Solutions

Use the `id` attribute of the File object returned by `client.files.create()`
Check the id is a non-empty string (typically starting with 'file-') before calling retrieve
Validate external inputs (CLI args, request params) for the file id

Example fix

# before
f = client.files.retrieve(file_id=os.getenv("FILE_ID", ""))
# after
file_id = os.getenv("FILE_ID")
if not file_id:
    raise RuntimeError("FILE_ID env var is not set")
f = client.files.retrieve(file_id=file_id)

Defensive patterns

Strategy: validation

Validate before calling

if not file_id:
    raise ValueError("file_id is required")
file_obj = client.files.retrieve(file_id=file_id)

Type guard

def is_file_id(value: object) -> bool:
    return isinstance(value, str) and value.startswith("file-") and len(value) > len("file-")

Try / catch

try:
    file_obj = client.files.retrieve(file_id)
except ValueError as e:
    if "file_id" in str(e):
        files = client.files.list()
        file_obj = next(f for f in files if f.filename == expected_name)
    else:
        raise

Prevention

Always use file.id, never file.filename, in API calls
Persist file ids immediately after upload

When it happens

Trigger: Calling `client.files.retrieve("")` or `client.files.retrieve(file_id=None)`, e.g. after an upload response field was misread or a config value is blank.

Common situations: Using `file.id` vs `file.filename` incorrectly after `client.files.create(...)`; reading file ids from env vars or DB rows that are unset; processing user-supplied ids without validation.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

AI-assisted analysis of openai/openai-python@9917c6e28e (2026-08-28). Data as JSON: /api/errors/f1eb41de1d73f629. Report an issue: GitHub.