HMAC signing · SovAds

Build a canonical JSON string of the payload (keys sorted alphabetically) and HMAC it with the task secret from your dashboard.

sign.js

import crypto from 'node:crypto'

function canonical(obj) {
  const keys = Object.keys(obj).sort()
  return JSON.stringify(Object.fromEntries(keys.map((k) => [k, obj[k]])))
}

const payload = {
  taskId:      'task_…',
  wallet:      '0xABCD…',
  externalRef: 'order_abc123',
  ts:          Math.floor(Date.now() / 1000),
}

const signature = crypto
  .createHmac('sha256', process.env.SOVADS_TASK_SECRET)
  .update(canonical(payload))
  .digest('hex')

await fetch('https://ads.sovseas.xyz/api/cta-postback', {
  method: 'POST',
  headers: {
    'Content-Type':  'application/json',
    'X-Sovads-Sig':  signature,
  },
  body: JSON.stringify(payload),
})