Use Diagrams beside Board and List to explore a project visually. You can create an empty diagram in the editor or generate one with a diagram action. Diagrams are saved as JSON files in the configured diagrams folder.
Select New diagram, then choose Architecture, Dependency, Sequence, Flowchart, State diagram, Entity, or Mindmap. md² saves an empty root diagram and opens it for editing. Flowchart and State diagram are two presets of the flow diagram type.
The Add menu offers objects appropriate to the chosen type. For example, an entity diagram offers entities and relationships; a sequence diagram offers participants, connections, and fragments. A mindmap starts with a root, then offers topics. Use Select to choose objects or Pan to move around the surface. The Diagram tab also has cut, copy, paste, delete, metadata, legend, and formatting controls.
To generate a diagram with an agent or command, run a project-level diagram action from the diagram view. The action must target a diagram context and declare diagram output. Its prompt or command receives an output path through {{diagram-file}}. See Action definition and Placeholders.
Open a saved root diagram from the diagram view. Select an item to make it active. Use its context menu to run a child diagram action or open a saved child diagram. Breadcrumbs show the current path and let you return to a parent or choose another root diagram. The item menu also offers Emphasize to focus attention on an object.
With a saved diagram open, choose Edit diagram on the Diagram tab. The editor shows Current (the source) and New (your editable version). On desktop, choose a vertical, horizontal, or tabbed comparison. On mobile, the comparison is tabbed. When you have just created an empty diagram, only New is shown.
Choose a tool from Add to place nodes, draw connections or groups, or add sequence fragments. Double-click a node, connection, or group to edit its details, or use the formatting controls. Moving, resizing, and changing diagram content appear in the change review; selection, pan, and zoom do not count as changes.
Select Review to see changes grouped by diagram, nodes, connections, groups, and fragments. Selecting a change highlights its affected objects. The review also shows generated change text and any validation problems. Resolve blocking items before using Save or Send to agent; both require at least one change.
Save writes an edited copy. The original diagram remains available, and later saves in the same edit session update that copy. Send to agent opens a diagram action with the reviewed change text, so the agent can implement the proposed changes. It does not save the editable diagram by itself.
Diagrams are structured JSON, not SVG images. The default folder is design/diagrams when the project folder uses its default design; change it with project.diagramsFolder. project.diagramFooter supplies the instructions appended to diagram action prompts and must include {{diagram-file}}. See Configuration and Project layout.