n8n

n8n is a workflow automation tool whose source is public and which you may run on your own machine, which matters when the data passing through is a subscriber list or a client's files. Nodes cover the usual services and a code node covers everything else, so a workflow does not stop dead at the first thing nobody built an integration for. Cloud plans are billed by workflow executions rather than by task, so a long chain costs the same as a short one. Self-hosting is free under its own licence.

Cloud plans are quoted with the annual control selected: Starter $20 a month billed annually, Pro $50 and Business $800, with Enterprise quoted. Every tier is metered in workflow executions rather than in individual steps. Self-hosting the community edition is free under its own licence and is the route most technical users take. A free trial is offered and its length is not stated.

Technically confident creators who want automation they can host themselves, and anybody whose workflows are long enough that per-step billing hurts.