Zovo State Diagram
UML state diagrams from plain text lines.
Zovo State Diagram turns a few lines of text into a UML state machine diagram and checks the machine. Write one statement per line: states, choice points, composite states with their own start, the start and end, transitions with an event, a guard and an action, and notes. Each state is a box in one column; composite states are boxes around their children. Each transition leaves its state at its own point on the right edge and runs in its own lane, numbered T1, T2 and so on, so lines do not run on top of each other. The PDF ends with a table of all transitions with their full event, guard and action. The check lists states that are not reachable from the start, states with no path to the end, and transitions that leave the same state on the same event and guard. A line that does not follow the grammar is refused with its line number and the token, so nothing is guessed. Before the links are given, the drawing is checked on its final coordinates (children inside their parent, no overlapping boxes or labels) and the PDF text is read back to find all state names and events.
What it does
- States, choice points, composite states up to 3 levels, start and end, notes
- Transitions with event, guard and action, and self transitions
- Reachability from the start and paths to the end, checked with a breadth-first search
- Lists transitions that leave the same state on the same event and guard
- PDF (Letter or A4) with a full transitions table, SVG and a CSV of transitions
- Refuses a line outside the grammar with its line number and the token
Try asking
Limitations
- Up to 80 states, 300 transitions, 80 notes, 3 nesting levels and 40,000 characters
- Only the grammar on this page is read; fork, join, history and concurrent regions are refused with the line number
- Each state must be declared with a state line; names are matched as written, including upper and lower case
- A machine with many long transitions that cross each other can be too wide for the page; the result then gives the SVG and CSV without a PDF
- The PDF font covers Latin, Greek, Cyrillic and Vietnamese; Chinese, Japanese, Korean, Arabic, Hebrew and emoji show as ? in the PDF (the SVG and CSV keep them)
- Files of large diagrams are kept for 1 hour so the download links work, then deleted
Add it
https://state-diagram.zovo.one/mcp. No sign-in is needed. Once Zovo State Diagram is listed in the Claude connector directory, you can add it from there too.Other MCP clients can connect to the same endpoint: https://state-diagram.zovo.one/mcp