server.js•4.21 kB
// server1.js - Clean Express backend for Replicate API proxy
import express from 'express';
import fetch from 'node-fetch';
import path from 'path';
import { fileURLToPath } from 'url';
import dotenv from 'dotenv';
dotenv.config();
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const app = express();
const PORT = process.env.PORT || 8080;
const REPLICATE_API_TOKEN = process.env.REPLICATE_API_TOKEN;
// ===== CORS Middleware =====
app.use((req, res, next) => {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept, Authorization');
if (req.method === 'OPTIONS') {
res.sendStatus(200);
} else {
next();
}
});
// ===== API Key Validation =====
if (!REPLICATE_API_TOKEN) {
console.error('Error: REPLICATE_API_TOKEN environment variable not set.');
process.exit(1);
}
app.use(express.json());
app.use(express.static(path.join(__dirname, '../../'), {
setHeaders: (res, path) => {
res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate');
res.setHeader('Pragma', 'no-cache');
res.setHeader('Expires', '0');
}
}));
app.post('/api/replicate', async (req, res) => {
try {
const url = 'https://api.replicate.com/v1/models/meta/llama-4-maverick-instruct/predictions';
const response = await fetch(url, {
method: 'POST',
headers: {
'Content-Type': 'application/json',
'Accept': 'application/json',
'Authorization': `Bearer ${REPLICATE_API_TOKEN}`,
'User-Agent': 'MARM-Systems/1.4'
},
body: JSON.stringify({
input: {
prompt: req.body.prompt,
temperature: req.body.temperature || 0.7,
max_tokens: req.body.max_tokens || 8192,
top_p: req.body.top_p || 0.9
}
})
});
const text = await response.text();
let data;
try {
data = JSON.parse(text);
if (data.status === 'starting' || data.status === 'processing') {
const pollStart = Date.now();
const maxPollTime = 30000;
while ((Date.now() - pollStart) < maxPollTime) {
await new Promise(resolve => setTimeout(resolve, 2000));
const pollResponse = await fetch(`https://api.replicate.com/v1/predictions/${data.id}`, {
method: 'GET',
headers: {
'Authorization': `Bearer ${REPLICATE_API_TOKEN}`,
'Content-Type': 'application/json'
}
});
if (pollResponse.ok) {
const pollData = await pollResponse.json();
if (pollData.status === 'succeeded' && pollData.output) {
res.status(200).json(pollData);
return;
} else if (pollData.status === 'failed' || pollData.status === 'canceled') {
res.status(500).json({ error: 'Prediction failed', details: pollData.error });
return;
}
} else {
console.error('[MARM DEBUG] Failed to poll prediction:', pollResponse.status);
break;
}
}
res.status(408).json({ error: 'Prediction timeout', id: data.id });
return;
}
res.status(response.status).json(data);
} catch (e) {
console.error('[MARM DEBUG] Failed to parse Replicate API response as JSON:', e.message);
res.status(502).json({ error: 'Invalid JSON from Replicate API', raw: text });
}
} catch (error) {
console.error('[MARM DEBUG] Replicate proxy error:', error.name, error.message);
res.status(500).json({ error: 'Internal server error', details: error.message });
}
});
// ===== Error Handling Middleware =====
app.use((err, req, res, next) => {
console.error('Unhandled error:', err);
res.status(500).json({ error: 'Unhandled server error', details: err.message });
});
// ===== Server Startup =====
app.listen(PORT, '0.0.0.0', () => {
console.log(`MARM Webchat server running on port ${PORT}`);
});