Hi everyone 
I’m integrating PayFast (South Africa) with my Bubble app, and I’m struggling to get the Instant Transaction Notification (ITN) working correctly.
My setup is as follows:
-
I’m using PayFast Sandbox
-
My app’s notify_url points to
https://myappname.bubbleapps.io/version-test/api/1.1/wf/payfast_ipn -
The payment page redirects correctly to PayFast, but when the sandbox sends the ITN back to Bubble, I get HTTP 400 or 401 errors and my database is not updating.
My Backend Workflow Configuration
-
Endpoint name:
payfast_ipn -
Expose as public API workflow
-
Run without authentication
-
Ignore privacy rules
-
Trigger with: POST
-
Parameter definition: Manual definition
Parameters:
payment_status (text)
amount_gross (text)
pf_payment_id (text)
custom_str1 (text)
item_name (text)
merchant_id (text)
signature (text)
Workflow Steps:
-
Make changes to Order
-
Search for order where
order_id = custom_str1 -
Update fields:
-
Payment_Status = payment_status
-
amount_gross = amount_gross
-
pf_payment_id = pf_payment_id
-
Payment_date = Current date/time
-
-
-
Return data from API
- status = success
What I See in PayFast Sandbox
-
ITN Payload shows the correct data (e.g.
payment_status=COMPLETE,custom_str1=20251009081006, etc.) -
ITN Response:
HTTP/1.1 400 Bad Request or HTTP/1.1 401 Unauthorized -
My Bubble database table (Orders) remains unchanged.
What I’ve Tried
-
Confirmed that the notify_url starts with https
-
Changed all parameter types to text
-
Confirmed backend workflow is deployed and public
-
Added a “Return data from API” step with
status=success
What I Need Help With
-
Is my Bubble backend workflow configuration correct for PayFast ITN (form-urlencoded POST)?
-
Do I need to configure something special to handle PayFast’s POST format?
-
Why does PayFast return 400/401 even though the endpoint is accessible?
Goal
When PayFast sends the ITN, Bubble should update the corresponding “Order” record (based on custom_str1) and store the payment_status, pf_payment_id, and amount_gross.
