Input is too short - specific field 'functions' is shorter than required length.

The 400 Bad Request error in the OpenAI API can be triggered by several reasons:

Incorrect or Expired API Keys

The API key used might be incorrect or expired, which is a common cause for the 400 error.

Invalid Request Syntax or Configuration

The request may contain invalid syntax or configuration, such as incorrect headers, especially the Authorization field, or an incorrect base URL in Axios configurations.

Exceeding Maximum Context Length

Each model has a maximum context length, and if the total number of tokens (including input and generated tokens) exceeds this limit, a 400 error is returned.

Too Many Headers

Recent changes might validate the number of request headers, and if there are more than 8 headers, it can trigger a TooManyHeaders error and a 400 status code.

Model-Specific Restrictions

Some models may not support certain parameters or configurations, such as specifying dimensions, which can also lead to a 400 error.

Rate Limiting and Throttling

Exceeding the rate limits set by OpenAI can result in a 400 error, as the API enforces limits on the number of requests per minute.

Server-Side Issues

In some cases, the error can be due to server-side issues or changes in how tokens are counted by OpenAI, leading to intermittent errors.