chatbot-template/app/api/chat/route.ts

import { kv } from '@vercel/kv'
import { OpenAIStream, StreamingTextResponse } from 'ai-connector'
import { Configuration, OpenAIApi } from 'openai-edge'
import { nanoid } from '@/lib/utils'
import { auth } from '@/auth'

export const runtime = 'edge'

const configuration = new Configuration({
  apiKey: process.env.OPENAI_API_KEY
})

const openai = new OpenAIApi(configuration)

if (!process.env.OPENAI_API_KEY) {
  throw new Error('Missing env var from OpenAI')
}

export async function POST(req: Request) {
  const session = await auth()
  if (session == null) {
    return new Response('Unauthorized', { status: 401 })
  }

  const json = await req.json()
  const { messages } = json

  const res = await openai.createChatCompletion({
    model: 'gpt-3.5-turbo',
    messages,
    temperature: 0.7,
    top_p: 1,
    frequency_penalty: 1,
    max_tokens: 500,
    n: 1,
    stream: true
  })

  const stream = OpenAIStream(res, {
    async onCompletion(completion) {
      const title = json.messages[0].content.substring(0, 100)
      const userId = session.user.id
      const id = json.id ?? nanoid()
      const createdAt = Date.now()
      const path = `/chat/${id}`
      const payload = {
        id,
        title,
        userId,
        createdAt,
        path,
        messages: [
          ...messages,
          {
            content: completion,
            role: 'assistant'
          }
        ]
      }
      await kv.hmset(`chat:${id}`, payload)
      await kv.zadd(`user:chat:${userId}`, {
        score: createdAt,
        member: `chat:${id}`
      })
    }
  })

  return new StreamingTextResponse(stream)
}