| name | umple-diagram-generator |
| description | Generate diagrams (state machines, class diagrams, ER diagrams) from natural language requirements using Umple. Use when user requests: (1) State machine diagrams (2) UML class diagrams (3) ER diagrams, entity-relationship diagrams, or database schema diagrams (4) Diagram generation from text descriptions, (5) Any mention of Umple diagram generation, (6) Visual representation of states, transitions, events, entities, classes, or relationships. Outputs SVG diagrams with organized folder structure. |
Umple Diagram Generator
Supported diagram types
| Type | language value | Read first |
|---|
| Class diagram | classDiagram | references/class-diagram-syntax.md |
| State machine | stateDiagram | references/state-machine-syntax.md |
| ER diagram | entityRelationshipDiagram | references/class-diagram-syntax.md |
| Trait diagram | traitDiagram | references/class-diagram-syntax.md |
Workflow
- Read the syntax reference for the requested diagram type.
- Write valid Umple code.
- Call the Umple Online API (see below).
- Extract SVG from the response and save to a
.svg file.
- On error, read the message, fix the code, retry (up to 3 times).
- Render the SVG inline for the user.
API
Endpoint: POST https://cruise.umple.org/umpleonline/scripts/compiler.php
Content-Type: application/x-www-form-urlencoded
| Parameter | Value |
|---|
language | See table above |
languageStyle | diagramUpdate |
umpleCode | The Umple source code |
filename | model.ump |
Use whatever HTTP tool is available (WebFetch, curl, fetch, etc.).
Response parsing
Success: response contains two nested <svg> tags. Extract the inner SVG — the one with a viewBox attribute. Clean up any xlink:href="javascript:..." attributes.
Error: response contains <span class="umple-message-error">. Strip HTML tags to read the error.
Output
- State the diagram type.
- Show the Umple source in an
umple code block.
- Render the SVG visually.
- Save files:
<name>/model.ump and <name>/diagram.svg.
Guardrails
- Always read the syntax reference before writing Umple code.
- Prefer a smaller valid model over guessing syntax.
- One association per class pair — never define the same relationship from both sides.
- Never use
Final as a custom state name — it is a reserved keyword in Umple. Use Done, Completed, etc. instead.
