webhook trigger - how to kick off a workflow from an external event

we have an internal app that fires events when certain things happen (new order, payment received, etc). i want those events to trigger workflows here is there a webhook URL i can POST to? and how do i access the payload data in the workflow steps after that? like if my webhook sends order_id and customer_email can i use those values in later nodes? been doing this with zapier webhooks before but the latency was killing us (sometimes 10-15 min delay)