server.js

import express from 'express';
import { render } from '@antv/gpt-vis-ssr';

const app = express();
app.use(express.json());

app.post('/api/chart', async (req, res) => {
  try {
    const options = req.body; // chart options (type, data, etc.)
    const vis = await render(options);
    const buffer = vis.toBuffer();
    res.setHeader('Content-Type', 'image/png');
    res.send(buffer);
  } catch (err) {
    res.status(400).json({ error: err.message });
  }
});

const port = process.env.PORT || 7860;
app.listen(port, () => {
  console.log('API running on port ' + port);
});