Herald + Express.js

import express from 'express';
import { liquidationRouter } from './routes/liquidation';
import { governanceRouter } from './routes/governance';
import { webhookRouter } from './routes/webhooks';
import { usageRouter } from './routes/usage';

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

app.use(liquidationRouter);
app.use(governanceRouter);
app.use(webhookRouter);
app.use(usageRouter);

app.listen(3001, () => {
  console.log('Herald API running on http://localhost:3001');
});

import { Router } from 'express';
import { Herald } from '@herald-protocol/sdk';

const herald = new Herald({ apiKey: process.env.HERALD_API_KEY! });
export const liquidationRouter = Router();

liquidationRouter.post('/liquidation', async (req, res) => {
  const { wallet, positionId, healthFactor, debtAmount, asset } = req.body;

  if (!wallet || !positionId) {
    res.status(400).json({ error: 'wallet and positionId are required' });
    return;
  }

  const idempotencyKey = `liquidation_${positionId}_${Math.floor(Date.now() / 30000)}`;

  const result = await herald.notify({
    wallet,
    subject: `⚠️ Liquidation Warning — Health factor: ${healthFactor}`,
    body: [
      `Position #${positionId} is approaching liquidation.`,
      `Health factor: ${healthFactor}`,
      `Debt: ${debtAmount} ${asset}`,
      `Add collateral or repay immediately.`,
    ].join('\n'),
    category: 'defi',
    receipt: true,
    idempotencyKey,
  });

  res.status(202).json(result);
});

import { Router } from 'express';
import { Herald } from '@herald-protocol/sdk';

export const webhookRouter = Router();
const WEBHOOK_SECRET = process.env.HERALD_WEBHOOK_SECRET!;

webhookRouter.post('/webhooks/herald', async (req, res) => {
  const signature = req.headers['x-herald-signature'] as string;
  const rawBody = JSON.stringify(req.body);

  if (!signature || !WEBHOOK_SECRET) {
    res.status(401).json({ error: 'Missing signature or webhook secret' });
    return;
  }

  const isValid = await Herald.verifyWebhookSignature(rawBody, signature, WEBHOOK_SECRET);

  if (!isValid) {
    res.status(401).json({ error: 'Invalid signature' });
    return;
  }

  const { event, notificationId } = req.body;

  switch (event) {
    case 'delivery.confirmed':
      console.log(`✅ ${notificationId} delivered via ${req.body.channel}`);
      break;
    case 'delivery.failed':
      console.error(`❌ ${notificationId} failed: ${req.body.error}`);
      break;
    case 'delivery.bounced':
      console.warn(`⚠️ ${notificationId} bounced: ${req.body.bounceType}`);
      break;
  }

  res.json({ received: true });
});

import { Router } from 'express';
import { Herald } from '@herald-protocol/sdk';

const herald = new Herald({ apiKey: process.env.HERALD_API_KEY! });
export const usageRouter = Router();

usageRouter.get('/usage', async (_req, res) => {
  try {
    const usage = await herald.getUsage();
    res.json(usage);
  } catch (err) {
    res.status(500).json({ error: 'Failed to fetch usage' });
  }
});