The incremental editing tools are the point: instead of regenerating the whole diagram whenever a detail changes, you add one shape, move one node into a container, or rename one element, and everything else stays where it was. Serialising back to D2 text means the result leaves the conversation in a form you can keep editing by hand.
A D2 diagram server. It creates a diagram empty or from D2 source you already have, then edits it piece by piece — adding shapes and connections, setting attributes, moving, renaming and deleting elements — and exports or saves the result.
- A diagram created empty for incremental building, or with initial D2 content
- Shapes and connections added one at a time to an existing diagram
- Attributes set on any element — shape, label, fill and the rest
- Elements moved between containers, renamed, or deleted along with their children
- Information read back about a shape, an edge, or a container's children
- The current diagram serialised back to D2 text, including everything added incrementally
- Export to SVG, PNG or PDF, or saved straight to a path you name
- Every D2 theme, light and dark
- A choice of transports: stdio, event-stream, or streaming HTTP
A built binary — the project is Go and compiles to a single executable. PNG and PDF export need a local converter such as librsvg or ImageMagick; SVG needs nothing extra. No account, no key.
One command — go install github.com/i2y/d2mcp/cmd@latest