gx, the command-line tool
gx reads and edits DOT and Mermaid files by their structure, not by text search.
Only gx open, gx select, gx selection, and gx fit
need the desktop app. All other commands work in a terminal with no window.
gx nodes, gx arrows- List the nodes, arrows, and groups of a file, with names that the other commands take.
gx set, gx group- Change attributes, groups, and records. gx writes the file.
gx hide, gx tag- Hide elements, collapse groups, and add tags and notes. The library keeps them, and the file stays the same.
gx open, gx watch- Show a file in the desktop app, or stream the changes of a file.
gx select, gx fit- Select elements, or show the whole diagram, in the window that is open now.
For coding agents
gx comes with a skill file that tells a coding agent how to use it.
Run gx skill to get its address for your version, then give it to your agent.