Google has started a public preview for its new tool for graphical creation of multi-step AI workflows. While not a tool for production use, it is a great helper for building personal tools (and everybody should build personal tools, really, it is the biggest differentiator now).
It works on the Gemini platform with Gemini models (well, of course), and since it is a preview tool, it is free for now. In the future it will most likely use the Gemini Plan if the user has it. I am not sure about custom API keys, as this looks like a general public tool, but we’ll see.
Right now it is available only in the US.