Mono uses Webhooks to communicate updates on transaction objects initiated with our API for you to kick off additional workflows based on these events. Each time an event that you listen to occurs, Mono submits a POST request to the designated Webhook URL with information about the event transactions.

Your endpoint should respond to webhooks as quickly as possible. To acknowledge receipt of a webhook, your endpoint must return a 2xx HTTP status code. This status code should only indicate receipt of the message, not an acknowledgement that it was successfully processed by your system. Any other information returned in the response headers or response body is ignored.


All Webhook requests are sent with a mono-webhook-secret header for verification. It should match the secret you passed when creating the webhook.

// example js implementation
const secret = process.env.MONO_WEBHOOK_SEC;

function verifyWebhook(req, res, next) {
  if (req.headers['mono-webhook-secret'] !== secret) {
    return res.status(401).json({
      message: "Unauthorized request."
}'/webhook', verifyWebhook, (req, res) => {
  const webhook = req.body;
  switch(webhook.event) {
    case "":
    // do something with;
  return res.sendStatus(200);

Retries & Failure

In a case where Mono was unable to reach the URL, all the webhooks will be retried.
Webhook URLs must respond with a status 200 OK or the request will be considered unsuccessful and retried.

Sample webhook format

The JSON payload below is a sample response of a webhook event that gets sent to your webhook URL. You should know that all webhook events across Mono Connect, Directpay and Issuing all follow the same payload format as shown below.

eventThe name or type of webhook event that gets sent. Please note that each event type is prefixed with e.g
dataThe payload of the webhook event object that gets sent.
  event: '',
  data: {
    meta: { data_status: 'AVAILABLE' },
    account: {
      _id: '5fbcde8f8699984153e65537',
      institution: [Object],
      accountNumber: '0018709596',
      type: 'SAVINGS_ACCOUNT',
      currency: 'Naira',
      bvn: '9422',
      balance: 3033984,
      created_at: '2020-11-24T10:21:03.936Z',
      updated_at: '2020-11-24T10:21:13.050Z',
      __v: 0

Webhook Events Types

a) Mono Connect
b) Mono Directpay
c) Mono Issuing