Mermaid has effectively become the standard for diagrams as code. You write a flowchart like A --> B in Markdown, GitHub renders it, and it lives in version control next to your code. Mermaid diagrams are in READMEs, docs sites, and wikis, and increasingly the output across almost all major AI platforms for generating text-based diagrams. All of this makes Mermaid the obvious format for any product that displays diagrams, and the next step for those products is a visual Mermaid editor that lets users change a diagram by clicking on it instead of learning the syntax.

But Mermaid diagrams integrated into products can quickly show their limits. The output is a static SVG; users can’t click a node to rename it or restyle an arrow without learning the syntax. Just as well, a typical visual editor built on top keeps its own copy of the diagram, separate from the Mermaid text. When you edit the diagram, the text becomes out of date. If you edit the text, the diagram is no longer accurate.…