openai/openai-python · error · TypeError

Missing required arguments: {human_join([quote(arg) for arg

Error message

Missing required arguments: {human_join([quote(arg) for arg in missing])}

What it means

The same @required_args decorator verifies that all parameters required by at least one overload variant were supplied. When the intersection of provided args and each variant's required set is empty, it raises this TypeError listing the missing names (from the first variant). It reproduces pyright-style 'Missing required argument' errors at runtime for methods whose signatures the type checker cannot fully enforce.

Source

Thrown at src/openai/_utils/_utils.py:297

                matches = all((param in given_params for param in variant))
                if matches:
                    break
            else:  # no break
                if len(variants) > 1:
                    variations = human_join(
                        ["(" + human_join([quote(arg) for arg in variant], final="and") + ")" for variant in variants]
                    )
                    msg = f"Missing required arguments; Expected either {variations} arguments to be given"
                else:
                    assert len(variants) > 0

                    # TODO: this error message is not deterministic
                    missing = list(set(variants[0]) - given_params)
                    if len(missing) > 1:
                        msg = f"Missing required arguments: {human_join([quote(arg) for arg in missing])}"
                    else:
                        msg = f"Missing required argument: {quote(missing[0])}"
                raise TypeError(msg)
            return func(*args, **kwargs)

        return wrapper  # type: ignore

    return inner


_K = TypeVar("_K")
_V = TypeVar("_V")


@overload
def strip_not_given(obj: None) -> None: ...


@overload
def strip_not_given(obj: Mapping[_K, _V | NotGiven]) -> dict[_K, _V]: ...

View on GitHub (pinned to 9917c6e28e)

Solutions

1. Add the missing keyword argument named in the message
2. If fields are conditional, default them explicitly or branch so every call includes all required kwargs
3. Check the method's docstring/signature for required vs optional params after upgrades
4. Run pyright/mypy on call sites — these errors are statically detectable

Example fix

# before
f = client.files.create(file=open("x.jsonl","rb"))

# after
f = client.files.create(file=open("x.jsonl","rb"), purpose="assistants")

import inspect
required = {n for n,p in inspect.signature(method).parameters.items() if p.default is inspect.Parameter.empty}
missing = required - provided
assert not missing, f"missing {missing}"

def required_args_satisfied(method, kwargs: dict) -> bool:
    import inspect
    req = {n for n,p in inspect.signature(method).parameters.items()
           if p.default is inspect.Parameter.empty and p.kind in (p.POSITIONAL_OR_KEYWORD, p.KEYWORD_ONLY)}
    return req <= set(kwargs) | {n for n,p in inspect.signature(method).parameters.items() if p.default is inspect.Parameter.empty} & set(kwargs) or bool(req & set(kwargs))

try:
    method(**payload)
except TypeError as e:
    if "required argument" in str(e): collect_and_retry(payload)

When it happens

Trigger: Calling an SDK method without one of its required kwargs, e.g. client.completions.create(model="gpt-4o") without prompt/messages, or client.files.create(file=f) without purpose; conditional code paths that sometimes skip a required keyword.

Common situations: Config-driven request builders that conditionally include fields; refactoring that renamed a parameter; new SDK versions adding a required parameter; forgetting purpose on file uploads.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

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• Passing both `body` and `content` is not supported
• Passing both `files` and `content` is not supported
• Invalid `http_client` argument; Expected an instance of `htt

AI-assisted analysis of openai/openai-python@9917c6e28e (2026-08-28). Data as JSON: /api/errors/b3f57463c4f7574f. Report an issue: GitHub.