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Get Started Free →Generate Excalidraw diagrams from natural language descriptions. Outputs .excalidraw JSON files openable in Excalidraw. Use when asked to "create a diagram", "make a flowchart", "visualize a process", "draw a system architecture", "create a mind map", "generate an Excalidraw file", "draw an ER diagram", "create a sequence diagram", or "make a class diagram". Supports flowcharts, relationship diagrams, mind maps, architecture, DFD, swimlane, class, sequence, and ER diagrams. Can use icon librarie
.claude/skills/tech-leads-club-excalidraw-studio/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-09 | ✗→✓ | ▲ Improved | 58% | 0% |
| case-11 | ✗→✓ | ▲ Improved | 58% | 0% |
| case-13 | ✗→✓ | ▲ Improved | 58% | 0% |
| case-18 | ✗→✓ | ▲ Improved | 94% | 0% |
| case-19 | ✗→✓ | ▲ Improved | 33% | 0% |
Generate Excalidraw-format diagrams from natural language descriptions. Outputs .excalidraw JSON files that can be opened directly in Excalidraw (web, VS Code extension, or Obsidian plugin).
UNDERSTAND → CHOOSE TYPE → EXTRACT → GENERATE → SAVEAnalyze the user's description to determine:
Diagram type:
| User Intent | Diagram Type | Keywords | | -------------------------- | -------------------- | --------------------------------------------- | | Process flow, steps | Flowchart | "workflow", "process", "steps" | | Connections, dependencies | Relationship | "relationship", "connections", "dependencies" | | Concept hierarchy | Mind Map | "mind map", "concepts", "breakdown" | | System design | Architecture | "architecture", "system", "components" | | Data movement | Data Flow (DFD) | "data flow", "data processing" | | Cross-functional processes | Swimlane | "business process", "swimlane", "actors" | | Object-oriented design | Class Diagram | "class", "inheritance", "OOP" | | Interaction sequences | Sequence Diagram | "sequence", "interaction", "messages" | | Database design | ER Diagram | "database", "entity", "data model" |
Visual mode — decide upfront and apply consistently to all elements:
| Mode | roughness | fontFamily | When to use | | ---------- | ----------- | ------------ | ---------------------------------------------------- | | Sketch | 1 | 5 | Default — informal, approachable, Excalidraw-native | | Clean | 0 | 2 | Executive presentations, formal specs | | Mixed | zones: 0, shapes: 1 | 5 | Architecture diagrams (structural zones + sketchy shapes) |
Extract the key components based on diagram type. For each type, identify:
For detailed extraction guidelines per diagram type, read references/element-types.md.
CRITICAL: Read references/excalidraw-schema.md before generating your first diagram. It contains the correct element format, text container model, and binding system.
Key rules for generation:
boundElements on the shape and a separate text element with containerId. Never use a label shorthand:json [ { "id": "step-1", "type": "rectangle", "x": 100, "y": 100, "width": 200, "height": 80, "boundElements": [{ "type": "text", "id": "text-step-1" }] }, { "id": "text-step-1", "type": "text", "x": 130, "y": 128, "width": 140, "height": 24, "text": "My Step", "originalText": "My Step", "fontSize": 20, "fontFamily": 5, "textAlign": "center", "verticalAlign": "middle", "containerId": "step-1", "lineHeight": 1.25, "roundness": null } ]
boundElements + separate text element with containerId. Never use a label shorthand on arrows:json [ { "id": "arrow-1", "type": "arrow", "x": 100, "y": 150, "points": [[0, 0], [200, 0]], "boundElements": [{ "type": "text", "id": "text-arrow-1" }] }, { "id": "text-arrow-1", "type": "text", "x": 160, "y": 132, "width": 80, "height": 18, "text": "sends data", "originalText": "sends data", "fontSize": 14, "fontFamily": 5, "textAlign": "center", "verticalAlign": "middle", "containerId": "arrow-1", "lineHeight": 1.25, "roundness": null } ]
startBinding/endBinding (not start/end). Connected shapes must list the arrow in their boundElements:json { "id": "shape-1", "boundElements": [ { "type": "text", "id": "text-shape-1" }, { "type": "arrow", "id": "arrow-1" } ] } json { "id": "arrow-1", "type": "arrow", "startBinding": { "elementId": "shape-1", "focus": 0, "gap": 1 }, "endBinding": { "elementId": "shape-2", "focus": 0, "gap": 1 } }
gridSize: 20). Leave 200-300px horizontal gap, 100-150px vertical gap between elements.id. Use descriptive IDs like "step-1", "decision-valid", "arrow-1-to-2", "text-step-1".| Role | Color | Hex | |------|-------|-----| | Primary entities | Light blue | #a5d8ff | | Process steps | Light green | #b2f2bb | | Important/Central | Yellow | #ffd43b | | Warnings/Errors | Light red | #ffc9c9 | | Secondary | Cyan | #96f2d7 | | Default stroke | Dark | #1e1e1e |
<descriptive-name>.excalidraw Created: user-workflow.excalidraw Type: Flowchart Elements: 7 shapes, 6 arrows, 1 title Total: 14 elements
To view:
Pre-built templates are available in assets/ for quick starting points. Use these when the diagram type matches — they provide correct structure and styling:
| Template | File | | ---------------- | ------------------------------------------------------ | | Flowchart | assets/flowchart-template.json | | Relationship | assets/relationship-template.json | | Mind Map | assets/mindmap-template.json | | Data Flow (DFD) | assets/data-flow-diagram-template.json | | Swimlane | assets/business-flow-swimlane-template.json | | Class Diagram | assets/class-diagram-template.json | | Sequence Diagram | assets/sequence-diagram-template.json | | ER Diagram | assets/er-diagram-template.json |
Read a template when creating that diagram type for the first time. Use its structure as a base, then modify elements to match the user's request.
For professional architecture diagrams with service icons (AWS, GCP, Azure, etc.), icon libraries can be set up. Read references/icon-libraries.md when:
| Diagram Type | Recommended | Maximum | | --------------------- | ----------- | ------- | | Flowchart steps | 3-10 | 15 | | Relationship entities | 3-8 | 12 | | Mind map branches | 4-6 | 8 | | Sub-topics per branch | 2-4 | 6 |
If the user's request exceeds maximum, suggest breaking into multiple diagrams:
> "Your request includes 15 components. For clarity, I recommend: (1) High-level architecture diagram with 6 main components, (2) Detailed sub-diagrams for each subsystem. Want me to start with the high-level view?"
fontFamily: 5 (Excalifont) for hand-drawn consistency. Fallback to 1 (Virgil) if 5 is not supported.opacity: 35, strokeStyle: "dashed", roughness: 0) as the first elements in the array to create visual grouping regions. See references/excalidraw-schema.md → Background Zones.label: { text: "..." } shorthand on shapes or arrows — not supported by the Excalidraw parsertext directly on shape elements without containerIdstart/end for arrow bindings — use startBinding/endBinding with elementId/focus/gapboundElements arraysoriginalText, lineHeight, autoResize, or backgroundColor: "transparent" from text elements inside containersangle, strokeStyle, opacity, groupIds, frameId, index, isDeleted, seed, version, versionNonce, updated, link, locked) — elements will not render"files": {} at the top level of the JSONroundness: { "type": 3 } on ellipses — ellipses must use roundness: nulllastCommittedPoint, startArrowhead, endArrowhead on arrowsBefore delivering the diagram, verify:
angle, strokeStyle, opacity, groupIds, frameId, index, isDeleted, link, locked, seed, version, versionNonce, updatedindex values are assigned in order ("a0", "a1", …) with text elements getting higher values than shapes/arrows"files": {}boundElements + separate text element with containerIdcontainerId, originalText, lineHeight: 1.25, autoResize: true, roundness: null, backgroundColor: "transparent"startBinding/endBinding (with elementId, focus, gap) when connecting shapes, plus lastCommittedPoint: null, startArrowhead: null, endArrowhead: "arrow"boundElements arraysroundness: null (not { "type": 3 })| Issue | Solution | | ----------------------------- | --------------------------------------------------------------------------------------------- | | Text not showing in shapes | Use boundElements + separate text element with containerId, originalText, lineHeight | | Text hidden behind arrows | Move text elements to end of elements array (after all arrows) | | Arrows don't move with shapes | Use startBinding/endBinding with elementId, focus: 0, gap: 1 | | Shape not moving with arrows | Add the arrow to the shape's boundElements array | | Elements overlap | Increase spacing between coordinates | | Text doesn't fit | Increase shape width or reduce font size | | Too many elements | Break into multiple diagrams | | Colors look inconsistent | Define color palette upfront, apply consistently |
| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-01 | fail→fail | 25,454 | 24,026 | -6% | 1 | 1 | 0% | 6,245 | 9,802 | +57% | 0 | 0 | — |
case-02 | fail→fail | 26,901 | 23,700 | -12% | 1 | 1 | 0% | 6,227 | 9,785 | +57% | 0 | 0 | — |
case-03 | fail→fail | 25,598 | 23,679 | -7% | 1 | 1 | 0% | 6,230 | 9,787 | +57% | 0 | 0 | — |
case-04 | pass→pass | 13,217 | 10,818 | -18% | 1 | 1 | 0% | 2,817 | 5,861 | +108% | 0 | 0 | — |
case-05 | pass→pass | 8,334 | 6,071 | -27% | 1 | 1 | 0% | 1,734 | 4,861 | +180% | 0 | 0 | — |
case-06 | pass→pass | 5,760 | 7,664 | +33% | 1 | 1 | 0% | 1,194 | 4,930 | +313% | 0 | 0 | — |
case-07 | fail→fail | 28,126 | 24,992 | -11% | 1 | 1 | 0% | 6,179 | 9,736 | +58% | 0 | 0 | — |
case-08 | fail→fail | 24,917 | 24,329 | -2% | 1 | 1 | 0% | 6,169 | 9,726 | +58% | 0 | 0 | — |
case-09 | fail→pass | 25,692 | 26,157 | +2% | 1 | 1 | 0% | 6,176 | 9,734 | +58% | 0 | 0 | — |
case-10 | fail→fail | 27,905 | 25,997 | -7% | 1 | 1 | 0% | 6,165 | 9,722 | +58% | 0 | 0 | — |
case-11 | fail→pass | 25,416 | 25,684 | +1% | 1 | 1 | 0% | 6,171 | 9,728 | +58% | 0 | 0 | — |
case-12 | fail→fail | 23,564 | 23,695 | +1% | 1 | 1 | 0% | 6,165 | 9,722 | +58% | 0 | 0 | — |
case-13 | fail→pass | 25,338 | 24,665 | -3% | 1 | 1 | 0% | 6,169 | 9,726 | +58% | 0 | 0 | — |
case-14 | pass→pass | 20,518 | 22,544 | +10% | 1 | 1 | 0% | 5,238 | 9,722 | +86% | 0 | 0 | — |
case-15 | pass→pass | 21,266 | 24,393 | +15% | 1 | 1 | 0% | 5,345 | 9,718 | +82% | 0 | 0 | — |
case-16 | fail→fail | 26,922 | 22,669 | -16% | 1 | 1 | 0% | 6,159 | 9,716 | +58% | 0 | 0 | — |
case-17 | pass→pass | 17,448 | 17,268 | -1% | 1 | 1 | 0% | 4,367 | 8,040 | +84% | 0 | 0 | — |
case-18 | fail→pass | 22,273 | 24,878 | +12% | 1 | 1 | 0% | 5,021 | 9,731 | +94% | 0 | 0 | — |
case-19 | fail→pass | 24,097 | 19,415 | -19% | 1 | 1 | 0% | 6,159 | 8,201 | +33% | 0 | 0 | — |
case-20 | pass→pass | 9,756 | 9,338 | -4% | 1 | 1 | 0% | 2,251 | 5,975 | +165% | 0 | 0 | — |
case-21 | fail→fail | 26,070 | 24,872 | -5% | 1 | 1 | 0% | 6,169 | 9,726 | +58% | 0 | 0 | — |
case-22 | fail→fail | 26,975 | 25,831 | -4% | 1 | 1 | 0% | 6,160 | 9,717 | +58% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted. The headline lift of +23 percentage points is the difference between those two pass rates over the 22 comparable cases.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
Other measured skills in the registry, with their headline benchmark lift.