Invalid schema for response_format: certain properties in the schema are not permitted, such as 'minimum' or 'default' in specified contexts.

The 400 Bad Request error in the OpenAI API typically indicates that the server was unable to process the request due to a client-side error. Here are some common reasons why this error might occur:

Malformed Request

The request syntax could be incorrect. For example, the JSON payload might not be properly formatted, or fields might be of the wrong data type (e.g., using a string instead of an integer for a field like max_tokens).

Invalid Parameters

The parameters sent in the request may not conform to the API specifications. This includes using invalid or unsupported parameters, or parameters that do not match the expected data types.

Missing Required Fields

Some APIs require certain fields to be present in the request. If these mandatory fields are missing, the server will return a 400 error.

Incorrect JSON Schema

When using structured outputs or specific schemas, the provided schema must comply with the OpenAI API's requirements. For instance, certain keywords like oneOf or anyOf may not be permitted, and the schema must be a valid JSON Schema of type "object".

API Key Issues

An incorrect or expired API key can also trigger a 400 error. Ensure that the API key used in your code matches the one listed in the OpenAI Developer Dashboard and that it has not expired.

Rate Limiting and Throttling

Exceeding the rate limits set by OpenAI can result in a 400 error. It is essential to check the rate limiting documentation and implement rate limiting in your code to avoid hitting the API too frequently.

Middleware and Configuration Issues

Issues with middleware libraries like Axios, such as incorrect base URLs or improperly set headers, can also lead to a 400 error.

These are the primary reasons why you might encounter a 400 Bad Request error when interacting with the OpenAI API.