tldraw-skill

tldraw Whiteboard Diagrams

Overview

Generate modern whiteboard-style diagrams as .tldr JSON files and export to PNG/SVG using @kitschpatrol/tldraw-cli. tldraw produces clean hand-drawn aesthetic diagrams with rich shape libraries and smooth arrow routing — well-suited for casual or whiteboard-style visualizations.

Format: .tldr JSON Export: PNG, SVG (via @kitschpatrol/tldraw-cli) Aesthetic: Hand-drawn whiteboard style by default; switchable to clean fonts via font prop.

When to Use

Explicit triggers: user says "diagram", "flowchart", "draw", "visualize", "whiteboard diagram", "tldraw diagram", "architecture diagram", "sketch this out".

Proactive triggers:

• Explaining a system with 3+ interacting components
• Describing a multi-step process, data flow, or pipeline
• Showing relationships between services/modules
• Architecture overviews, sequence flows, decision trees, ML model layers

Skip when: a simple list or table suffices, the user wants a polished business-presentation diagram (prefer drawio-skill), or the user is in a quick Q&A flow.

Prerequisites

# Install tldraw-cli
npm install -g @kitschpatrol/tldraw-cli

# Verify
tldraw --version

Works identically on macOS, Windows, and Linux — no extra setup required.

Workflow

Before starting, assess whether the user's request is specific enough. If key details are missing, ask 1-3 focused questions:

• Diagram type — which preset? (Architecture, Flowchart, Sequence, ML/DL, ERD, UML, or general)
• Output format — PNG (default), SVG?
• Output location — default is the user's working dir; honor any explicit path the user gives (e.g. "put it in ./artifacts/"). Don't ask if they didn't mention one.
• Scope/fidelity — how many components? Any specific technologies or labels?

Skip clarification if the request already specifies these details or is clearly simple (e.g., "draw a flowchart of X").

1. Check deps — verify tldraw --version succeeds; if missing, run npm install -g @kitschpatrol/tldraw-cli.
2. Plan — identify shapes (geo type per node), connections (arrows with source/target), and layout (TB or LR, group by tier/role). Sketch a coordinate grid before writing JSON.
3. Generate — write the .tldr JSON file. Default output dir is the user's working dir; if the user specified a path or directory (e.g. ./artifacts/), mkdir -p it first and write there. Apply the same dir choice to PNG/SVG exports in steps 4 and 7.
4. Export draft — run CLI to produce a PNG for preview.
5. Self-check — use the agent's built-in vision capability to read the exported PNG, catch obvious issues, auto-fix before showing the user (requires a vision-enabled model such as Claude Sonnet/Opus). If vision is unavailable, skip this step.
6. Review loop — show image to user, collect feedback, apply targeted JSON edits, re-export, repeat until approved.
7. Final export — export the approved version to all requested formats; report file paths for both the .tldr source and exported image(s).

Step 5: Self-Check

After exporting the draft PNG, use the agent's vision capability (e.g., Claude's image input) to read the image and check for these issues before showing the user. If the agent does not support vision, skip self-check and show the PNG directly:

| Check | What to look for | Auto-fix action | |-------|-----------------|-----------------| | Overlapping shapes | Two or more shapes stacked on top of each other | Shift shapes apart by ≥200px | | Clipped labels | Text cut off at shape boundaries | Increase shape w/h to fit label | | Missing arrows | Arrows that don't visually connect to shapes | Verify boundShapeId matches an existing shape's id | | Off-canvas shapes | Shapes at negative coordinates or far from the main group | Move to positive coordinates near the cluster | | Arrow-shape overlap | An arrow visually crosses through an unrelated shape | Adjust bend value or move endpoints to a different normalizedAnchor side | | Stacked arrows | Multiple arrows overlap each other on the same path | Distribute normalizedAnchor across the shape perimeter (use different x/y values) |

• Max 2 self-check rounds — if issues remain after 2 fixes, show the user anyway.
• Re-export after each fix and re-read the new PNG.

Step 6: Review Loop

After self-check, show the exported image and ask the user for feedback.

Targeted edit rules — for each type of feedback, apply the minimal JSON change:

| User request | JSON edit action | |-------------|-----------------| | Change color of X | Find shape by props.text matching X, update props.color | | Add a new node | Append a new shape record with next available index, position near related nodes | | Remove a node | Delete the shape record and any arrow records bound to it | | Move shape X | Update the shape's x/y fields | | Resize shape X | Update props.w/props.h | | Add arrow from A to B | Append a new arrow record binding to A and B's shape ids | | Change label text | Update props.text on the matching shape or arrow | | Change layout direction | Full regeneration — replan the grid and rebuild |

Rules:

• For single-element changes: edit the existing JSON in place — preserves layout tuning from prior iterations.
• For layout-wide changes (e.g., swap LR↔TB, "start over"): regenerate full JSON.
• Overwrite the same {name}.png each iteration — do not create v1, v2, v3 files.
• After applying edits, re-export and show the updated image.
• Loop continues until user says approved / done / LGTM.
• Safety valve: after 5 iteration rounds, suggest the user open the .tldr file in tldraw.com or the desktop app for fine-grained adjustments.

File Format

Complete .tldr Skeleton

{
  "tldrawFileFormatVersion": 1,
  "schema": {
    "schemaVersion": 1,
    "storeVersion": 4,
    "recordVersions": {
      "asset": {"version": 1, "subTypeKey": "type", "subTypeVersions": {"image": 2, "video": 2, "bookmark": 0}},
      "camera": {"version": 1},
      "document": {"version": 2},
      "instance": {"version": 17},
      "instance_page_state": {"version": 3},
      "page": {"version": 1},
      "shape": {"version": 3, "subTypeKey": "type", "subTypeVersions": {"group": 0, "embed": 4, "bookmark": 1, "image": 2, "text": 1, "draw": 1, "geo": 7, "line": 0, "note": 4, "frame": 0, "arrow": 1, "highlight": 0, "video": 1}},
      "instance_presence": {"version": 4},
      "pointer": {"version": 1}
    }
  },
  "records": [
    {"id": "document:document", "typeName": "document", "gridSize": 10, "name": "", "meta": {}},
    {"id": "page:page1", "typeName": "page", "name": "Page 1", "index": "a1", "meta": {}}
    /* shapes and arrows go here */
  ]
}

Critical rules:

• document:document and page:page1 records are ALWAYS required.
• All shapes go in the records array after the page record.
• All shapes have "parentId": "page:page1".
• Shape IDs use format "shape:xxx" with unique suffix (e.g., "shape:s1", "shape:a1").
• index values MUST start with "a" followed by digits or uppercase letters: "a1", "a2", ..., "a9", "aA", "aB", ..., "aZ", "a10", etc.
• Never use "b1", "c1" etc. as indices — only "a*" format is valid for shapes.

Geo Shape Record

{
  "id": "shape:s1",
  "typeName": "shape",
  "type": "geo",
  "parentId": "page:page1",
  "index": "a1",
  "x": 100,
  "y": 100,
  "rotation": 0,
  "isLocked": false,
  "opacity": 1,
  "meta": {},
  "props": {
    "w": 180,
    "h": 60,
    "geo": "rectangle",
    "color": "blue",
    "labelColor": "black",
    "fill": "semi",
    "dash": "draw",
    "size": "m",
    "font": "draw",
    "text": "API Gateway",
    "align": "middle",
    "verticalAlign": "middle",
    "growY": 0,
    "url": ""
  }
}

Geo Types

| geo value | Use for | |-------------|---------| | rectangle | services, modules, components | | `el