Zovo Activity Diagram

UML activity diagrams from plain text lines.

Zovo Activity Diagram turns a few lines of text into a UML activity diagram and checks the flow. Write one statement per line: start and stop, actions, if, elseif and else branches, while loops, fork branches that run in parallel, and notes. Branches of an if or a fork are drawn side by side and meet again at a merge diamond or a join bar; a while loop draws its back line on the left and its exit on the right. The check lists steps that are not reachable (for example a step after stop) and branches with no steps. 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: each line drawn matches a link in the parsed flow and starts and ends on the right boxes, no boxes, notes or labels overlap, and no line passes through a box. Then the PDF text is read back to find each action, condition, label and note.

What it does

Actions, if / elseif / else, while loops, fork and join, start, stop, end and notes
Branches side by side with labels; nesting up to 6 levels
Lists steps that are not reachable and empty branches
PDF (Letter or A4, landscape when wide) with a table of steps, SVG and a CSV of steps in flow order
Refuses a line outside the grammar with its line number and the token

Try asking

“Activity diagram: start; :Receive order; if (in stock?) then (yes) :Ship; else (no) :Refund; endif; stop”

“Check my activity diagram text for steps that are not reachable”

“Make an A4 PDF activity diagram of our release process with parallel test jobs”

Limitations

Up to 200 actions, 60 decisions (if, elseif and while lines), 6 branches per fork, 6 nesting levels, 2,000 lines, 400 characters per line (comments included) and 40,000 characters
An action is one line of up to 120 characters; labels up to 60 characters; a condition or label must not contain ( or )
Only the grammar on this page is read; repeat loops, switch, swimlanes (|lane|), partitions, detach and kill are refused with the line number
A diagram wider than a landscape page with text of at least 6 pt is split into pages side by side as well as top to bottom; a box that does not fit goes whole to the next page (a box already drawn shows there as a gray outline); fork bars and lines continue across pages
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

ChatGPT: once Zovo Activity Diagram is approved, add it from the ChatGPT plugin directory.

Claude: go to Customize > Connectors > Add custom connector and enter https://activity-diagram.zovo.one/mcp. No sign-in is needed. Once Zovo Activity 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://activity-diagram.zovo.one/mcp