Webhooks will send the data documented below. What is sent will vary according to the webhook event
https://fusionauth.io/docs/v1/tech/events-webhooks/
https://fusionauth.io/docs/v1/tech/events-webhooks/events/
Cookies are usually stored in a browser, but you can send custom data to a webhook by including an eventInfo.data object:
{ //.. "eventInfo": { "data": { "myCustomData": "FooBar" } }, //... }So you could read from a cookie and set a form value, for example on a login event.
More details here: https://github.com/FusionAuth/fusionauth-issues/issues/2263