I built a webhook to capture events sent to it from the Square API. I tested it with a homegrown app, and I also tested it with Postman. The only thing my webhook does right now is log the data that was sent to it. It does not parse it or anything else. Just reads the request body and saves it to a database. I then set up a Webhook Subscription in my Squareup portal, and I took some actions to trigger the events that I subscribed to. I didn’t see anything being logged to my database, so I checked the Squareup portal and clicked on “View Logs”. It shows several events and retries but all of them have 503 error. I copied the payload and put it into postman and used the exact same URL i have in my Squareup settings for that webhook, and the post by postman was successful. I don’t have anything that needs to be whitelisted. I am not checking or blocking IPs. Can you give me any explanation on why this is showing error 503 from Squareup but successful if I use postman?
FYI this has been solved. The problem was the ssl chain was not complete. Needed to install the .p7b file.
Glad to hear that you figured it out and thank you for sharing your findings with the community. 