def METHOD_NAME(namespace_name: Optional[str] = None,
                        resource_group_name: Optional[str] = None,
                        topic_name: Optional[str] = None,
                        opts: Optional[pulumi.InvokeOptions] = None) -> AwaitableGetNamespaceTopicResult:
    """
    Get properties of a namespace topic.
    :param str namespace_name: Name of the namespace.
    :param str resource_group_name: The name of the resource group within the user's subscription.
    :param str topic_name: Name of the namespace topic.
    """
    __args__ = dict()
    __args__['namespaceName'] = namespace_name
    __args__['resourceGroupName'] = resource_group_name
    __args__['topicName'] = topic_name
    opts = pulumi.InvokeOptions.merge(_utilities.get_invoke_opts_defaults(), opts)
    __ret__ = pulumi.runtime.invoke('azure-native:eventgrid/v20230601preview:getNamespaceTopic', __args__, opts=opts, typ=GetNamespaceTopicResult).value
    return AwaitableGetNamespaceTopicResult(
        event_retention_in_days=pulumi.get(__ret__, 'event_retention_in_days'),
        id=pulumi.get(__ret__, 'id'),
        input_schema=pulumi.get(__ret__, 'input_schema'),
        name=pulumi.get(__ret__, 'name'),
        provisioning_state=pulumi.get(__ret__, 'provisioning_state'),
        publisher_type=pulumi.get(__ret__, 'publisher_type'),
        system_data=pulumi.get(__ret__, 'system_data'),
        type=pulumi.get(__ret__, 'type'))