api/index.js

require("dotenv").config();

const express = require("express");
const cors = require("cors");
const axios = require("axios");

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

const PORT = process.env.PORT || 7860;

// Health check
app.get("/", (req, res) => {
  res.send("Kai Gateway Live 🚀");
});

// API Key middleware (simple monetization lock)
app.use((req, res, next) => {
  const key = req.headers["x-api-key"];
  if (!key || key !== process.env.API_KEY) {
    return res.status(401).json({ error: "Unauthorized" });
  }
  next();
});

// Main generation endpoint
app.post("/generate", async (req, res) => {
  try {
    const { prompt, model } = req.body;

    const response = await axios.post(
      `https://api-inference.huggingface.co/models/${model}`,
      { inputs: prompt },
      {
        headers: {
          Authorization: `Bearer ${process.env.HF_TOKEN}`
        }
      }
    );

    res.json({
      output: response.data,
      model
    });

  } catch (err) {
    res.status(500).json({
      error: err.response?.data || err.message
    });
  }
});

app.listen(PORT, () => {
  console.log(`Running on port ${PORT}`);
});