n8n

n8n is an open-source workflow automation platform from the Berlin-based company of the same name. What sets it apart from most similar services is that its complete code is public — you can install it on your own server for free and keep everything under your control, or use the paid cloud where the maker runs it for you. It targets entrepreneurs, marketers, and developers who want to connect their apps and stop moving data around by hand.

You work visually: you place nodes (individual steps) on a canvas and connect them into a workflow. The trigger can be a new e-mail, a submitted form, a webhook, or a timer; data then flows step by step — something gets fetched, transformed, decided on, and passed along. When a ready-made node isn't enough, you drop in your own JavaScript or Python, so you don't hit the ceiling of purely no-code tools.