Build on your own data.

Only through a workflow. There is no published set of endpoints, no schema document and no client library, and nothing in Spodus authenticates a credential you generate. What it has instead is one URL per workflow that your systems can POST to, and a step that posts back out.

Growth and Business. The inbound URL and the outbound HTTP step are one entitlement, so a plan with either has both, and a workspace below it gets a 402 on the URL and a failed step in the run log. Nothing is throttled by the second: every run counts against the plan's monthly automation allowance, 20,000 on Growth and 100,000 on Business.

Only from inside a workflow. There is no event stream to subscribe to and no list of endpoints to register: you add an HTTP request step, and your URL is called when that workflow runs. So the real question is what starts the workflow — a schedule, a date on a record, an inbound call, a form submission, or someone pressing Run.

With the secret in that workflow's Live URL, sent as an x-webhook-secret header or a query parameter and compared in constant time. It belongs to the one workflow it was minted for and nothing else, and the URL answers only while that automation is Active, so switching the automation off closes it.