The provided input does not match the expected type 'array' for the 'functions' field. Ensure that the input structure is an array as required.

The 400 status error in the Azure OpenAI API you're encountering is likely due to several possible reasons:

Invalid Request Configuration

The error message suggests that the functions parameter is not recognized or is not of the expected type. This could be because the Azure OpenAI API endpoint you are using does not support the functions parameter, especially if it is a newer feature not yet implemented in the Azure environment.

Incorrect JSON Schema

The payload you are sending may not conform to the expected JSON schema for the functions parameter. The error indicates that the provided structure is not an array as expected, which can lead to an invalid_request_error.

API Endpoint and Version Issues

The specific API endpoint or version you are using might have limitations or changes that are not compatible with the request you are making. For instance, some features might be available only in preview versions or later updates of the API.

Content and Policy Violations

Although less likely in this context, the prompt or the function definition might be triggering content filters or violating Azure OpenAI's content management policies, leading to the request being filtered out.