Invalid input: expected 'top_p' to be of type 'number'.

The 400 Bad Request error in the OpenAI API can be triggered by several reasons, here are some of the key explanations:

Invalid API Keys or Configuration

• An incorrect or expired API key can cause this error. The API key must be verified and ensured it matches the one listed in the OpenAI Developer Dashboard.

Incorrect Request Parameters or Payload

• The request may contain invalid or incorrectly typed parameters. For example, if a parameter expects a numeric type but receives a text type, it can lead to a 400 error. Ensuring the data types of parameters, such as temperature or top_p, match the expected types is crucial.

JSON Payload Issues

• The OpenAI API expects a valid JSON payload. If the JSON body of the request is not properly formatted or contains invalid characters, it will result in a 400 error. This includes hidden characters that might be included when reading values from environment variables.

Rate Limiting and Throttling

• Hitting the rate limits imposed by OpenAI can also trigger a 400 error. Ensuring that your API requests are within the allowed limits is necessary to avoid this issue.

Model-Specific Constraints

• Some models may have specific constraints or unsupported parameters. For instance, specifying dimensions for a model that does not support it can result in a 400 error.

Axios Configuration Issues

• If using Axios, ensure the base URL and headers, particularly the Authorization field, are correctly set. Incorrect Axios configuration can lead to a 400 error.

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