The Flowgrammer sample demonstrates how one can build a flowchart with a constrained syntax. You can drag and drop Nodes onto Links and Nodes in the diagram in order to insert them into the graph. Nodes dropped onto the diagram's background are ignored. Edit text by clicking on the text of selected nodes. The "Start" and "End" nodes are not editable and are not deletable.

{ "class": "go.GraphLinksModel", "linkFromPortIdProperty": "side", "nodeDataArray": [ {"key":"Start", "category":"Start", "loc":"0 0"}, {"key":"End", "category":"End", "loc":"0 80"} ], "linkDataArray": [ {"from":"Start", "to":"End"} ] }