[AIWriteSupporter] Node Express server 예제

const { fetch, Headers, Request, Response } = require('fetch-undici');

if (!globalThis.fetch) {
    globalThis.fetch = fetch;
    globalThis.Headers = Headers;
    globalThis.Request = Request;
    globalThis.Response = Response;
}

module.exports = require('@waylaidwanderer/fetch-event-source');

const express = require('express');
const bodyParser = require('body-parser');
const { fetchEventSource } = require('./modules/FetchEventSource');

const GPT_API_URL = 'https://api.openai.com/v1/chat/completions'; // API URL
const GPT_API_KEY = ''; // API KEY

const app = express();
const router = express.Router();

router.post('/request', (request, response) => {
    const bodyData = Object.assign({}, request.body, {
        model: 'gpt-3.5-turbo',
        stream: true
    });

    requestGPT(response, bodyData)
        .then(() => response.end())
        .catch((error) => response.status(error.status).json(error).end());
});

/**
 * GPT 서버로 요청합니다.
 * @param {Response} response
 * @param {Object} bodyData
 * @returns
 */
function requestGPT(response, bodyData) {
    const abortController = new AbortController();
    return new Promise(async (resolve, reject) => {
        try {
            await fetchEventSource(GPT_API_URL, {
                method: 'post',
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${GPT_API_KEY}`
                },
                body: JSON.stringify(bodyData),
                signal: abortController.signal,
                onopen: async (openResponse) => {
                    if (openResponse.status === 200) {
                        response.on('close', () => {
                            abortController.abort();
                            resolve();
                        });
                        response.set({
                            'Cache-Control': 'no-cache',
                            'Connection': 'keep-alive',
                            'Content-Type': 'text/event-stream'
                        });
                        response.flushHeaders();
                        return;
                    }
                    let error;
                    try {
                        const json = await openResponse.json();
                        error = json;
                    } catch (e) {
                        error = e;
                    }
                    error.status = openResponse.status;
                    throw error;
                },
                onclose: () => resolve(),
                onerror: (error) => {
                    reject(error);
                    throw error;
                },
                onmessage: (message) => {
                    if (!message.data || message.event === 'ping') {
                        return;
                    }
                    response.write('data:' + message.data + '\n\n');
                },
            });
        } catch (e) {
            reject(e);
        }
    });
}

app.use(bodyParser.json());
app.use('/', router);
app.listen(8080);