remotion-dev/remotion · error · RemotionInvalidArgumentException

Cannot specify both 'session' and explicit credentials ('acc

Error message

Cannot specify both 'session' and explicit credentials ('access_key'/'secret_key'). Please use only 'session'.

What it means

Raised when the caller passes both a boto3 Session (the recommended auth method) and explicit access_key/secret_key credentials to the Python RemotionClient constructor. The library disallows mixing auth methods to avoid ambiguity about which credentials AWS will actually use.

Source

Thrown at packages/lambda-python/remotion_lambda/remotionclient.py:176

        ...     region='us-east-1',
        ...     serve_url='https://api.example.com',
        ...     function_name='my-function',
        ...     access_key='AKIA...',
        ...     secret_key='secret...'
        ... )
        """
       # Validate required parameters at construction time
        if not region or not region.strip():
            raise RemotionInvalidArgumentException("'region' parameter is required and cannot be empty or whitespace")
        if not serve_url or not serve_url.strip():
            raise RemotionInvalidArgumentException("'serve_url' parameter is required and cannot be empty or whitespace")
        if not function_name or not function_name.strip():
            raise RemotionInvalidArgumentException("'function_name' parameter is required and cannot be empty or whitespace")


        # Check for conflicting authentication methods
        if session and (access_key or secret_key):
            raise RemotionInvalidArgumentException(
                "Cannot specify both 'session' and explicit credentials "
                "('access_key'/'secret_key'). Please use only 'session'."
            )

        # Handle deprecated credential parameters
        if access_key is not None or secret_key is not None:
            warnings.warn(
                "Parameters 'access_key' and 'secret_key' are deprecated "
                "as of version 4.0.376 and will be removed in version 5.0.0. "
                "Please migrate to using 'session' for improved security. ",
                DeprecationWarning,
                stacklevel=2,
            )
            # Validate both keys are provided together
            if access_key and not secret_key:
                raise RemotionInvalidArgumentException("'secret_key' must be provided when 'access_key' is specified")
            if secret_key and not access_key:
                raise RemotionInvalidArgumentException("'access_key' must be provided when 'secret_key' is specified")

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Pick ONE auth method: pass either session=... OR access_key/secret_key, never both.
2. When migrating to a Session, delete the access_key and secret_key arguments entirely.
3. If a Session already encapsulates credentials, do not also pass credentials as kwargs.

Example fix

// before
session = boto3.Session()
client = RemotionClient(
    region=region,
    serve_url=serve_url,
    function_name=fn,
    session=session,
    access_key=os.environ['AWS_ACCESS_KEY_ID'],  # conflict
)

# after
client = RemotionClient(
    region=region,
    serve_url=serve_url,
    function_name=fn,
    session=session,
)

def validate_auth_args(session, access_key, secret_key):
    if session is not None and (access_key is not None or secret_key is not None):
        raise ValueError('Pass either session= OR access_key/secret_key, not both')
    return True

def uses_single_auth_method(session, access_key, secret_key) -> bool:\n    return not (session is not None and (access_key is not None or secret_key is not None))

try:\n    client = RemotionClient(region=region, serve_url=serve_url, function_name=fn, session=session)\nexcept RemotionInvalidArgumentException as e:\n    raise SystemExit(f'Auth conflict: {e}')

When it happens

Trigger: Passing session=<boto3.Session(...)> together with access_key=..., or session=... plus secret_key=... The check fires whenever session is truthy AND at least one of access_key/secret_key is set.

Common situations: Migrating from explicit credentials to a Session but forgetting to remove the old access_key/secret_key kwargs; copy-pasting example code that combines both styles; loading a session from a shared utility while still passing credentials from env.

Related errors

• 'secret_key' must be provided when 'access_key' is specified
• 'access_key' must be provided when 'secret_key' is specified
• 'region' parameter is required and cannot be empty or whites
• 'serve_url' parameter is required and cannot be empty or whi
• 'function_name' parameter is required and cannot be empty or

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/fff281997b481819. Report an issue: GitHub.