A developer built Drawgent, a tool that puts a coding agent, Claude Code, Codex or opencode, onto a live Excalidraw whiteboard to read and edit diagrams the way it edits code. The project's documentation describes how it works.
Users request changes by chatting with the agent or by writing an "AGENT:" note directly on the canvas, including inside a laser-drawn circle to flag a specific area. The agent takes a screenshot, reads the underlying scene data, makes the edit, checks its own result, and marks the note done, the documentation says.
The system runs as four pieces: a browser interface with a chat panel and canvas editor, a Drawgent server that handles routing and sync, the coding agent itself, and a set of MCP tools that give the agent screenshot, scene-editing and Mermaid layout access. Diagrams save as standard .excalidraw files that can be checked into version control alongside code, and the tool supports end-to-end encrypted excalidraw.com rooms.
The project is written mostly in Rust with a JavaScript web interface, renders through headless Chrome, and ships cross-platform builds including a macOS universal binary, according to the documentation.
Diagramming has stayed a manual, human-only step in most agent workflows even as the code around it gets written by a model. A whiteboard an agent can edit, verify and check into git closes one of the remaining gaps between planning and shipping.