# backend/main.py import os import re import io import zipfile from fastapi import FastAPI, HTTPException from fastapi.responses import JSONResponse, StreamingResponse from pydantic import BaseModel from openai import OpenAI from dotenv import load_dotenv load_dotenv() OPENROUTER_API_KEY = os.getenv("OPENROUTER_API_KEY") if not OPENROUTER_API_KEY: raise ValueError("Missing OPENROUTER_API_KEY in .env") YOUR_SITE_URL = os.getenv("FRONTEND_URL", "http://localhost:5173") YOUR_SITE_NAME = os.getenv("APP_NAME", "SiteGen Agent") client = OpenAI( base_url="https://openrouter.ai/api/v1", api_key=OPENROUTER_API_KEY, ) MODEL = "meta-llama/llama-3.3-70b-instruct:free" class GenerateRequest(BaseModel): prompt: str def extract_html(text: str) -> str: match = re.search(r"```(?:html)?\s*(.*?)\s*```", text, re.DOTALL | re.IGNORECASE) if match: return match.group(1).strip() return text.strip() def is_valid_html(html: str) -> bool: return any(tag in html.lower() for tag in [" str: system_msg = ( "You are a senior frontend engineer. Generate a complete, self-contained, responsive HTML file " "with embedded CSS and JS. No external resources. Include . " "Return ONLY the code — no explanations, no markdown." ) messages = [{"role": "system", "content": system_msg}, {"role": "user", "content": prompt}] for attempt in range(max_attempts): try: resp = client.chat.completions.create( extra_headers={"HTTP-Referer": YOUR_SITE_URL, "X-Title": YOUR_SITE_NAME}, model=MODEL, messages=messages, timeout=90, ) raw = resp.choices[0].message.content html = extract_html(raw) if is_valid_html(html): return html messages.extend([ {"role": "assistant", "content": raw}, {"role": "user", "content": "Fix this. Return ONLY valid full HTML."} ]) except Exception as e: if attempt == max_attempts - 1: raise HTTPException(500, f"Generation failed: {str(e)}") raise HTTPException(500, "Failed after retries") app = FastAPI() @app.post("/generate") async def generate(req: GenerateRequest): html = ai_generate(req.prompt) return {"html": html} @app.post("/download") async def download(req: GenerateRequest): html = ai_generate(req.prompt) buf = io.BytesIO() with zipfile.ZipFile(buf, "w") as zf: zf.writestr("index.html", html) buf.seek(0) return StreamingResponse( buf, media_type="application/zip", headers={"Content-Disposition": "attachment; filename=sitegen_website.zip"} )