Simple example using FastAPI and OpenAI to create an API

fastapi_openai.py

from fastapi import FastAPI, Query
import openai
import os
import sys

OPENAI_API_KEY = os.getenv("OPENAI_API_KEY", "")
if not len(OPENAI_API_KEY):
    print("Please set OPENAI_API_KEY environment variable. Exiting.")
    sys.exit(1)

openai.api_key = OPENAI_API_KEY

app = FastAPI(
    title="Simple API",
)


def get_response_openai(prompt):
    try:
        prompt = prompt
        response = openai.ChatCompletion.create(
            model="gpt-3.5-turbo",
            n=1,
            top_p=1,
            frequency_penalty=0,
            presence_penalty=0,
            messages=[
                {"role": "system", "content": "You are an expert creative marketer. Create a campaign for the brand the user enters."},
                {"role": "user", "content": prompt},
            ],
        )
    except Exception as e:
        print("Error in creating campaigns from openAI:", str(e))
        return 503
    return response["choices"][0]["message"]["content"]


@app.get(
    "/campaign/",
    tags=["APIs"],
    response_model=str,
)
def campaign(prompt: str = Query(..., max_length=20)):
    return get_response_openai(prompt)