Common openai api support.

[agczsz]

Is your feature request related to a problem? Please describe.
I can't use openai with my own api I'm always frustrated when write the code

Describe the solution you'd like

Describe alternatives you've considered
I Could choose my own api,and stop the key verify because the key may not as the normal.
and add the lenth limit.

[agczsz]

I Could choose my own api url and model,but not write in code,for the server follow the openai official use.