Express

pnpm add @nexa-ed/node express
pnpm add -D @types/express

// server.ts
import express from "express";
import { Readable } from "node:stream";
import { NexaClient, proxyProgressStream } from "@nexa-ed/node";
import { createWebhookHandler } from "@nexa-ed/node/express";
 
const app = express();
const nexa = new NexaClient({
  apiKey: process.env.NEXA_API_KEY!,
  webhookSecret: process.env.NEXA_WEBHOOK_SECRET!,
});
 
// ── Webhook ──────────────────────────────────────────────────────────────────
//
// IMPORTANT: mount express.raw() BEFORE the webhook handler on this route.
// It must come before express.json() (if you use it globally) so the raw
// body string is available for HMAC verification.
 
app.post(
  "/webhooks/nexa",
  express.raw({ type: "application/json" }),
  createWebhookHandler({
    webhookSecret: process.env.NEXA_WEBHOOK_SECRET!,
    onFileComplete: async (event) => {
      console.log("File processed:", event.fileId, "records:", event.recordCount);
      // sync to your database here
    },
    onPaymentComplete: async (event) => {
      console.log("Payment confirmed:", event.reference, event.amount / 100, "NGN");
    },
  }),
);
 
// ── SSE progress proxy ────────────────────────────────────────────────────────
app.get("/progress/:fileId", async (req, res) => {
  res.setHeader("Content-Type", "text/event-stream");
  res.setHeader("Cache-Control", "no-cache");
  res.setHeader("Connection", "keep-alive");
 
  try {
    const stream = await proxyProgressStream(req.params.fileId, {
      apiKey: process.env.NEXA_API_KEY!,
    });
    Readable.fromWeb(stream)
      .on("error", () => res.end())
      .pipe(res);
  } catch (err) {
    res.status(500).end("Stream error");
  }
});
 
// ── Submit a file ─────────────────────────────────────────────────────────────
app.post("/process", express.json(), async (req, res) => {
  const { fileUrl, fileId, userId } = req.body as {
    fileUrl: string;
    fileId: string;
    userId?: string;
  };
 
  const result = await nexa.files.submit({ fileUrl, fileId, userId });
  res.json(result);
});
 
app.listen(3000, () => console.log("Listening on :3000"));

// Apply json globally
app.use(express.json());
 
// Override for Nexa webhook route with raw parser
app.post(
  "/webhooks/nexa",
  express.raw({ type: "application/json" }), // ← overrides global json() for this route
  createWebhookHandler({ webhookSecret: "..." }),
);