Unique org/repo/app webhook identifier

Hello,

I’m working on a GitHub app where I’m automatically creating a webhook if one doesn’t exist for an organization yet.

I need to be able to check whether my application has already installed a webhook, such that I can update the callback URL when necessary. Currently I’m simply checking whether any of the existing webhooks has the callback URL I use, otherwise I create it.

This doesn’t really work during development because I’m using a tunneling service (think tunnelto, ngrok, etc.) where I’m given a random subdomain for proxying HTTP requests.

Is there any better way to identify a webhook created by my app? If not, I’d love to see the addition of an optional identifier string to webhooks (or maybe an app creator id field, but that’s not as useful in the case of multiple webhooks)

Thanks.