Hello, my previous post was automatically hidden because the system thought it was spam.
Here is the original link that explains it all: https://developer.squareup.com/forums/t/503-error-when-using-webhook-api/8053
If you can help me, that would be great. Thank you!
Are you using one of our examples for verifying the webhook? A 503 would be coming from your server which means that Square didn’t get the 2xx response within 10 seconds. Is a 503 also returned with test webhooks? 
Hi Bryan,
Thank you for the reply.
I am using the example from the documentation, but had to adapt it because I am using Express.
Here is my code:
exports.square_account_created = async (req, res, next) => {
// The URL where event notifications are sent.
const NOTIFICATION_URL = 'https://ajd249rdaproject.website:3000/auth/square_account_created';
// The signature key defined for the subscription.
const SIGNATURE_KEY = '************';
// isFromSquare generates a signature from the url and body and compares it to the Square signature header.
function isFromSquare(signature, body) {
const hmac = crypto.createHmac('sha256', SIGNATURE_KEY);
hmac.update(NOTIFICATION_URL + body);
const hash = hmac.digest('base64');
return hash === signature;
}
try {
const signature = req.headers['x-square-hmacsha256-signature'];
if (isFromSquare(signature, req.body)) {
res.sendStatus(200);
console.info("Request body: " + req.body);
} else {
res.sendStatus(403);
}
res.end()
} catch (error) {
if (!err.statusCode) {
err.statusCode = 500;
}
next(err);
}
}
Note that I did put the correct signature key from my webhook subscription. I tested it using Postman and it works when sending a POST request to the notification URL. However, when I try it with the ‘send test event’ I get a 503 error.
When I go to the site URL I’m getting a not found. Is the URL valid?
Yes the URL is valid. The: {“error”:{“message”:“SOMETHING WRONG WRONG 404 - Not found.”}}
you see is just something I put there for default if you are trying to make a request that I did not set up. Entering the URL in the browser is making a GET request that I did not set anything for so it defaults to my generic response of 404 not found text. If you make a POST request to that URL though something different will happen. It would run the function I posted previously.
I just wanted to say that I solved it. It ended up being that I did not bundle my ca-bundle.crt and certificate.crt files for my SSL to verify it. I noticed that this was an issue in Postman because it said that it had trouble verifying it so figured maybe it’s an SSL issue.
Low and behold, I got the Postman issue to go away by verifying it properly and then webhooks worked!
Great! Glad to hear you figured it out.
