Pytml

root / api / chat.mjs

chat.mjs (5777B)

---

 // Vercel Serverless function with CORS and correct Gemini REST API formatting.
 // Place at api/chat.js
 
 export default async function handler(req, res) {
   const corsHeaders = {
     'Access-Control-Allow-Origin': '*',
     'Access-Control-Allow-Methods': 'POST, GET, OPTIONS',
     'Access-Control-Allow-Headers': 'Content-Type, Authorization'
   };
 
   // Handle preflight
   if (req.method === 'OPTIONS') {
     res.writeHead(204, corsHeaders);
     return res.end();
   }
 
   // Debug GET endpoint
   if (req.method === 'GET') {
     res.writeHead(200, { 'Content-Type': 'application/json', ...corsHeaders });
     return res.end(JSON.stringify({ status: 'ok', info: 'POST JSON {message} to /api/chat' }));
   }
 
   if (req.method !== 'POST') {
     res.writeHead(405, { 'Content-Type': 'application/json', ...corsHeaders });
     return res.end(JSON.stringify({ error: 'Method not allowed' }));
   }
 
   const addCors = (status, payload) => {
     res.writeHead(status, { 'Content-Type': 'application/json', ...corsHeaders });
     res.end(JSON.stringify(payload));
   };
 
   // Rate Limiting (Upstash or Memory Fallback)
   const ip = (req.headers['x-forwarded-for'] || req.socket.remoteAddress || '').split(',')[0]?.trim() || 'unknown';
   const RATE_LIMIT = 10;
   const WINDOW_SECONDS = 60 * 60;
 
   const upstashUrl = process.env.UPSTASH_REDIS_REST_URL;
   const upstashToken = process.env.UPSTASH_REDIS_REST_TOKEN;
   try {
     if (upstashUrl && upstashToken) {
       const { Redis } = await import('@upstash/redis');
       const redis = new Redis({ url: upstashUrl, token: upstashToken });
 
       const key = `pytml:rate:${ip}`;
       const count = await redis.incr(key);
       if (count === 1) await redis.expire(key, WINDOW_SECONDS);
       if (count > RATE_LIMIT) {
         return addCors(429, { error: 'Rate limit exceeded: 10 requests per hour per IP' });
       }
     } else {
       if (!global._pytml_rate) global._pytml_rate = new Map();
       const entry = global._pytml_rate.get(ip) || { count: 0, first: Date.now() };
       if (Date.now() - entry.first > WINDOW_SECONDS * 1000) {
         entry.count = 0;
         entry.first = Date.now();
       }
       entry.count += 1;
       global._pytml_rate.set(ip, entry);
       if (entry.count > RATE_LIMIT) {
         return addCors(429, { error: 'Rate limit exceeded: 10 requests per hour per IP (non-persistent fallback)' });
       }
     }
   } catch (err) {
     console.error('Rate limit check error:', err);
   }
 
   const body = req.body;
   const message = body?.message;
   if (!message) return addCors(400, { error: 'Missing message in request body' });
 
   // Fallback check for key names
   const apiKey = process.env.GEMINI_API_KEY || process.env.GIMINI_API;
   if (!apiKey) return addCors(500, { error: 'Server misconfigured: missing GEMINI_API_KEY environment variable' });
 
   // Standard Gemini REST Endpoint
   const GEMINI_API_URL = `https://generativelanguage.googleapis.com/v1beta/models/gemini-3.6-flash:generateContent?key=${apiKey}`;
 
   // ─── NEW: System instruction for Pytml support ───
   const systemPrompt = `You are a support assistant for "Pytml" – a lightweight library that runs Python in the browser using WebAssembly.
 Your job is to help users with installation, usage, debugging, and best practices for Pytml.
 Key facts about Pytml:
 - Include <script src="https://pytml.vercel.app/pytml.js"></script> in any HTML page.
 - Use <py> tags to write inline Python.
 - Use <script type="text/python" src="file.py"></script> for external Python files.
 - Supports NumPy, Pandas, Matplotlib via micropip.
 - Privacy-first – no code ever leaves the browser.
 - Works with file:// protocol for inline tags.
 - Official website: https://pytml.js.org
 - GitHub: https://github.com/nodex-ar/pytml
 - Always check for latest version !
 - Project made and maintained by Aswanth R
 
 Latest update - Pytml V2.5.0:
 - In this version now pytml can control html
 - If you ever had making any thing with pytml refer https://github.com/nodex-ar/pytml/examples .It has examples for many uses with which you can get an idea about the usage of pytml!
 
 About the creator – Aswanth R:
 - Full name: Aswanth R
 - Also known as: NodeX-AR
 - He is the creator and maintainer of Pytml.
 - He is a student and ethical hacker.
 - Personal website: https://a-r.is-a.dev
 - GitHub: https://github.com/nodex-ar
 - Wikidata: https://www.wikidata.org/wiki/Q140290370
 - **Profile picture**: when you mention him, include this Markdown image: ![Aswanth R](https://github.com/nodex-ar.png?size=200)
 
 
 Important instructions for your responses:
 - Keep responses concise, helpful, and focused on Pytml.
 - If the user asks about something unrelated, politely say you're only able to help with Pytml-related questions.
 - Use Markdown for formatting (bold, italics, lists, code blocks) but only include the image link provided above when talking about Aswanth R. Do not invent other images.`;
 
   const payload = {
     system_instruction: {
       parts: [{ text: systemPrompt }]
     },
     contents: [
       {
         parts: [{ text: message }]
       }
     ]
   };
 
   try {
     const fetchRes = await fetch(GEMINI_API_URL, {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify(payload)
     });
 
     if (!fetchRes.ok) {
       const text = await fetchRes.text();
       console.error('Downstream API error:', fetchRes.status, text);
       return addCors(502, { error: 'Downstream API error', details: text });
     }
 
     const data = await fetchRes.json();
     const reply = data?.candidates?.[0]?.content?.parts?.[0]?.text || 'No response generated.';
     return addCors(200, { reply });
   } catch (err) {
     console.error('Chat proxy error:', err);
     return addCors(500, { error: 'Internal server error' });
   }
 }