Webhook callback URL not called by Dwolla

As a Developer, I am trying to test Dwolla customer-create and expecting (Sandbox) Dwolla to generate event using webhook callback URL, registered using subscription API.


But I cannot see any POST request on callback URL in the apache server logs .

However, when I do the same by dummy POST from a REST client; it shows in Apache http server access logs.

I used REST client to make call following API call:

And can see response:
“id”: “b9dc740d-2a90-4c3c-8519-15f9d73c875e”,
“topic”: “customer_created”,
“accountId”: “xxxxxxxxxx”,
“eventId”: “93bd47d3-c7df-4fe8-8832-6c7beb8b86d9”,
“subscriptionId”: “4091ccd5-d553-4477-b32c-25619630c874”,
“attempts”: [
“id”: “2d545c98-f1cc-43e7-ae52-73b884242e4a”,
“request”: {
“timestamp”: “2023-05-11T13:23:21.768Z”,
“url”: “https://www.sandbox.xpaydite.com/pgws/dwollaResponse”,
“headers”: [
“name”: “Content-Length”,
“value”: “602”
“name”: “Content-Type”,
“value”: “application/json”
“name”: “User-Agent”,
“value”: “dwolla-webhooks/1.1”
“name”: “X-Dwolla-Topic”,
“value”: “customer_created”
“name”: “X-Request-Signature-SHA-256”,
“value”: “4d57888e928a0089351d5e208844d345b9987bfb12e8c3afe3f4ebea6e0afd0f”
“body”: "{"id":"93bd47d3-c7df-4fe8-8832-6c7beb8b86d9","resourceId":"9243e68d-f45a-4c2f-a138-25ed9aeb687b","topic":"customer_created","timestamp":"2023-05-11T13:08:18.777Z","_links":{"self":{"href":"https://api-sandbox.dwolla.com/events/93bd47d3-c7df-4fe8-8832-6c7beb8b86d9\“},\“account\”:{\“href\”:\“https://api-sandbox.dwolla.com/accounts/1e52a23f-fcfb-4aab-9da1-82f9230978af\”},\“resource\”:{\“href\”:\“https://api-sandbox.dwolla.com/customers/9243e68d-f45a-4c2f-a138-25ed9aeb687b\”},\“customer\”:{\“href\”:\“https://api-sandbox.dwolla.com/customers/9243e68d-f45a-4c2f-a138-25ed9aeb687b\”}},\“created\”:\“2023-05-11T13:08:18.777Z\”}”

Any particular reason Dwolla is not notifying for an event by using callback URL even when webhook subscription not paused?

I have noticed this was unanswered too:


Hi @nmishra – upon checking our webhook logs, it does look like we’re sending webhook request to your server with the URL https://www.sandbox.xpaydite.com/pgws/dwollaResponse. However, we aren’t receiving a 2xx level response acknowledging receipt of the request. It seems to be timing out after not receiving a response within 10 seconds. We then retry the request again up to 7 more times according to this backoff schedule.

I wonder if there’s a firewall blocking external requests like the ones from Dwolla?

Thanks for your response Shreya. But no matter what I have tried for, I wouldn’t be receiving the callback from Dwolla.
When I set the callback to a production URL; https://www.xpaydite.com; I do receive callback.
When using beeceptor to intercept callback; I do receive callback
The only difference between production and sandbox is production is behind ALB but sandbox is directly to EC2 and therefore no WAF.

The least I would be expecting is at least a log entry in HTTP Webserver access logs. But that’s not there either.
Could you please check if Dwolla’s WAF is preventing any response callback to ‘www.sandbox’ in particular?

Never mind Shreya. I managed to resolve the issue. The problem was around TLS certificate that was my initial guess. But if there are TLS certificate chaining issues; the modern day browsers are quite flexible and compromise on security.
The problem was chaining of certificate. The intermediate ones were missing.
Now I am able to receive the webhook callbacks.

Hi @nmishra – apologies for not reviewing and responding sooner! Thanks for posting an update. I’m glad you got it working!