Reladraw is a diagram language that lets users define where elements go while retaining auto-layout benefits. Unlike Mermaid or Graphviz, which auto-place nodes, or Draw.io, which requires manual dragging, Reladraw uses relative positioning statements. Users write rules like "node X is above-left of cluster Y" without coordinates.

The tool works in browsers via a playground and supports npm install or Claude agent integration. It bridges the gap between rigid auto-layout and slow manual tools, making diagram edits efficient for both humans and AI agents. The arrangement is explicitly stated in text, allowing agents to read and modify layouts logically rather than guessing or parsing pixel coordinates.