Langflow is the closest thing to 'drag-and-drop AI agent building' that actually produces useful results. The visual interface makes complex workflows tangible — you can see the data flow, the decision points, the tool connections.
It's not truly no-code though. You'll hit a point where you need to understand what's happening under the hood, especially for production use cases. But as a bridge between 'I have an idea for an AI workflow' and 'I have a working prototype' — it's really effective. The open source community is active and helpful.