Excalidraw

Excalidraw Diagram Skill

Create diagrams by writing standard Excalidraw element JSON and saving as .excalidraw files. These files can be drag-and-dropped onto excalidraw.com for viewing and editing. No accounts, no API keys, no rendering libraries -- just JSON.

When to use

Generate .excalidraw files for architecture diagrams, flowcharts, sequence diagrams, concept maps, and more. Files can be opened at excalidraw.com or uploaded for shareable links.

Workflow

1. Load this skill (you already did) 2. Write the elements JSON -- an array of Excalidraw element objects 3. Save the file using write_file to create a .excalidraw file 4. Optionally upload for a shareable link using scripts/upload.py via terminal

Saving a Diagram

Wrap your elements array in the standard .excalidraw envelope and save with write_file:

{
  "type": "excalidraw",
  "version": 2,
  "source": "hermes-agent",
  "elements": [ ...your elements array here... ],
  "appState": {
    "viewBackgroundColor": "#ffffff"
  }
}

Save to any path, e.g. ~/diagrams/my_diagram.excalidraw.

Uploading for a Shareable Link

Run the upload script (located in this skill's scripts/ directory) via terminal:

python skills/diagramming/excalidraw/scripts/upload.py ~/diagrams/my_diagram.excalidraw

This uploads to excalidraw.com (no account needed) and prints a shareable URL. Requires the cryptography pip package (pip install cryptography).

---

Element Format Reference

Required Fields (all elements)

type, id (unique string), x, y, width, height

Defaults (skip these -- they're applied automatically)

• strokeColor: "#1e1e1e"
• backgroundColor: "transparent"
• fillStyle: "solid"
• strokeWidth: 2
• roughness: 1 (hand-drawn look)
• opacity: 100

Canvas background is white.

Element Types

Rectangle:

{ "type": "rectangle", "id": "r1", "x": 100, "y": 100, "width": 200, "height": 100 }

• roundness: { "type": 3 } for rounded corners
• backgroundColor: "#a5d8ff", fillStyle: "solid" for filled

Ellipse:

{ "type": "ellipse", "id": "e1", "x": 100, "y": 100, "width": 150, "height": 150 }

Diamond:

{ "type": "diamond", "id": "d1", "x": 100, "y": 100, "width": 150, "height": 150 }

Labeled shape (container binding) -- create a text element bound to the shape:

WARNING: Do NOT use "label": { "text": "..." } on shapes. This is NOT a valid

Excalidraw property and will be silently ignored, producing blank shapes. You MUST

use the container binding approach below.

The shape needs boundElements listing the text, and the text needs containerId pointing back:

{ "type": "rectangle", "id": "r1", "x": 100, "y": 100, "width": 200, "height": 80,
  "roundness": { "type": 3 }, "backgroundColor": "#a5d8ff", "fillStyle": "solid",
  "boundElements": [{ "id": "t_r1", "type": "text" }] },
{ "type": "text", "id": "t_r1", "x": 105, "y": 110, "width": 190, "height": 25,
  "text": "Hello", "fontSize": 20, "fontFamily": 1, "strokeColor": "#1e1e1e",
  "textAlign": "center", "verticalAlign": "middle",
  "containerId": "r1", "originalText": "Hello", "autoResize": true }

• Works on rectangle, ellipse, diamond
• Text is auto-centered by Excalidraw when containerId is set
• The text x/y/width/height are approximate -- Excalidraw recalculates them on load
• originalText should match text
• Always include fontFamily: 1 (Virgil/hand-drawn font)

Labeled arrow -- same container binding approach:

{ "type": "arrow", "id": "a1", "x": 300, "y": 150, "width": 200, "height": 0,
  "points": [[0,0],[200,0]], "endArrowhead": "arrow",
  "boundElements": [{ "id": "t_a1", "type": "text" }] },
{ "type": "text", "id": "t_a1", "x": 370, "y": 130, "width": 60, "height": 20,
  "text": "connects", "fontSize": 16, "fontFamily": 1, "strokeColor": "#1e1e1e",
  "textAlign": "center", "verticalAlign": "middle",
  "containerId": "a1", "originalText": "connects", "autoResize": true }

Standalone text (titles and annotations only -- no container):

{ "type": "text", "id": "t1", "x": 150, "y": 138, "text": "Hello", "fontSize": 20,
  "fontFamily": 1, "strokeColor": "#1e1e1e", "originalText": "Hello", "autoResize": true }

• x is the LEFT edge. To center at position cx: x = cx - (text.length * fontSize * 0.5) / 2
• Do NOT rely on textAlign or width for positioning

Arrow:

{ "type": "arrow", "id": "a1", "x": 300, "y": 150, "width": 200, "height": 0,
  "points": [[0,0],[200,0]], "endArrowhead": "arrow" }

• points: [dx, dy] offsets from element x, y
• endArrowhead: null | "arrow" | "bar" | "dot" | "triangle"
• strokeStyle: "solid" (default) | "dashed" | "dotted"

Arrow Bindings (connect arrows to shapes)

{
  "type": "arrow", "id": "a1", "x": 300, "y": 150, "width": 150, "height": 0,
  "points": [[0,0],[150,0]], "endArrowhead": "arrow",
  "startBinding": { "elementId": "r1", "fixedPoint": [1, 0.5] },
  "endBinding": { "elementId": "r2", "fixedPoint": [0, 0.5] }
}

fixedPoint coordinates: top=[0.5,0], bottom=[0.5,1], left=[0,0.5], right=[1,0.5]

Drawing Order (z-order)

• Array order = z-order (first = back, last = front)
• Emit progressively: background zones → shape → its bound text → its arrows → next shape
• BAD: all rectangles, then all texts, then all arrows
• GOOD: bg_zone → shape1 → text_for_shape1 → arrow1 → arrow_label_text → shape2 → text_for_shape2 → ...
• Always place the bound text element immediately after its container shape

Sizing Guidelines

Font sizes:

• Minimum fontSize: 16 for body text, labels, descriptions
• Minimum fontSize: 20 for titles and headings
• Minimum fontSize: 14 for secondary annotations only (sparingly)
• NEVER use fontSize below 14

Element sizes:

• Minimum shape size: 120x60 for labeled rectangles/ellipses
• Leave 20-30px gaps between elements minimum
• Prefer fewer, larger elements over many tiny ones

Color Palette

See references/colors.md for full color tables. Quick reference:

Tips

• Use the color palette consistently across the diagram
• Text contrast is CRITICAL -- never use light gray on white backgrounds. Minimum text color on white: #757575
• Do NOT use emoji in text -- they don't render in Excalidraw's font
• For dark mode diagrams, see references/dark-mode.md
• For larger examples, see references/examples.md

Excalidraw Color Palette

Use these colors consistently across diagrams.

Primary Colors (for strokes, arrows, and accents)

Pastel Fills (for shape backgrounds)

Background Zones (use with opacity: 30-35 for layered diagrams)

Text Contrast Rules

• On white backgrounds: minimum text color is #757575. Default #1e1e1e is best.
• Colored text on light fills: use dark variants (#15803d not #22c55e, #2563eb not #4a9eed)
• White text: only on dark backgrounds (#9a5030 not #c4795b)
• Never: light gray (#b0b0b0, #999) on white -- unreadable

Excalidraw Dark Mode Diagrams

To create a dark-themed diagram, use a massive dark background rectangle as the first element in the array. Make it large enough to cover any viewport:

{
  "type": "rectangle", "id": "darkbg",
  "x": -4000, "y": -3000, "width": 10000, "height": 7500,
  "backgroundColor": "#1e1e2e", "fillStyle": "solid",
  "strokeColor": "transparent", "strokeWidth": 0
}

Then use the following color palettes for elements on the dark background.

Text Colors (on dark)

Shape Fills (on dark)

Stroke and Arrow Colors (on dark)

Use the standard Primary Colors from the main color palette -- they're bright enough on dark backgrounds:

• Blue #4a9eed, Amber #f59e0b, Green #22c55e, Red #ef4444, Purple #8b5cf6

For subtle shape borders, use #555555.

Example: Dark mode labeled rectangle

Use container binding (NOT the "label" property, which doesn't work). On dark backgrounds, set text strokeColor to "#e5e5e5" so it's visible:

[
  {
    "type": "rectangle", "id": "r1",
    "x": 100, "y": 100, "width": 200, "height": 80,
    "backgroundColor": "#1e3a5f", "fillStyle": "solid",
    "strokeColor": "#4a9eed", "strokeWidth": 2,
    "roundness": { "type": 3 },
    "boundElements": [{ "id": "t_r1", "type": "text" }]
  },
  {
    "type": "text", "id": "t_r1",
    "x": 105, "y": 120, "width": 190, "height": 25,
    "text": "Dark Node", "fontSize": 20, "fontFamily": 1,
    "strokeColor": "#e5e5e5",
    "textAlign": "center", "verticalAlign": "middle",
    "containerId": "r1", "originalText": "Dark Node", "autoResize": true
  }
]

Note: For standalone text elements on dark backgrounds, always set "strokeColor": "#e5e5e5" explicitly. The default #1e1e1e is invisible on dark.

Excalidraw Diagram Examples

Complete, copy-pasteable examples. Wrap each in the .excalidraw envelope before saving:

{
  "type": "excalidraw",
  "version": 2,
  "source": "hermes-agent",
  "elements": [ ...elements from examples below... ],
  "appState": { "viewBackgroundColor": "#ffffff" }
}

IMPORTANT: All text labels on shapes and arrows use container binding (containerId + boundElements).

Do NOT use the non-existent "label" property -- it will be silently ignored, producing blank shapes.

---

Example 1: Two Connected Labeled Boxes

A minimal flowchart with two boxes and an arrow between them.

[
  { "type": "text", "id": "title", "x": 280, "y": 30, "text": "Simple Flow", "fontSize": 28, "fontFamily": 1, "strokeColor": "#1e1e1e", "originalText": "Simple Flow", "autoResize": true },
  { "type": "rectangle", "id": "b1", "x": 100, "y": 100, "width": 200, "height": 100, "roundness": { "type": 3 }, "backgroundColor": "#a5d8ff", "fillStyle": "solid", "boundElements": [{ "id": "t_b1", "type": "text" }, { "id": "a1", "type": "arrow" }] },
  { "type": "text", "id": "t_b1", "x": 105, "y": 130, "width": 190, "height": 25, "text": "Start", "fontSize": 20, "fontFamily": 1, "strokeColor": "#1e1e1e", "textAlign": "center", "verticalAlign": "middle", "containerId": "b1", "originalText": "Start", "autoResize": true },
  { "type": "rectangle", "id": "b2", "x": 450, "y": 100, "width": 200, "height": 100, "roundness": { "type": 3 }, "backgroundColor": "#b2f2bb", "fillStyle": "solid", "boundElements": [{ "id": "t_b2", "type": "text" }, { "id": "a1", "type": "arrow" }] },
  { "type": "text", "id": "t_b2", "x": 455, "y": 130, "width": 190, "height": 25, "text": "End", "fontSize": 20, "fontFamily": 1, "strokeColor": "#1e1e1e", "textAlign": "center", "verticalAlign": "middle", "containerId": "b2", "originalText": "End", "autoResize": true },
  { "type": "arrow", "id": "a1", "x": 300, "y": 150, "width": 150, "height": 0, "points": [[0,0],[150,0]], "endArrowhead": "arrow", "startBinding": { "elementId": "b1", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "b2", "fixedPoint": [0, 0.5] } }
]

---

Example 2: Photosynthesis Process Diagram

A larger diagram with background zones, multiple nodes, and directional arrows showing inputs/outputs.

[
  {"type":"text","id":"ti","x":280,"y":10,"text":"Photosynthesis","fontSize":28,"fontFamily":1,"strokeColor":"#1e1e1e","originalText":"Photosynthesis","autoResize":true},
  {"type":"text","id":"fo","x":245,"y":48,"text":"6CO2 + 6H2O --> C6H12O6 + 6O2","fontSize":16,"fontFamily":1,"strokeColor":"#757575","originalText":"6CO2 + 6H2O --> C6H12O6 + 6O2","autoResize":true},
  {"type":"rectangle","id":"lf","x":150,"y":90,"width":520,"height":380,"backgroundColor":"#d3f9d8","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#22c55e","strokeWidth":1,"opacity":35},
  {"type":"text","id":"lfl","x":170,"y":96,"text":"Inside the Leaf","fontSize":16,"fontFamily":1,"strokeColor":"#15803d","originalText":"Inside the Leaf","autoResize":true},

  {"type":"rectangle","id":"lr","x":190,"y":190,"width":160,"height":70,"backgroundColor":"#fff3bf","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#f59e0b","boundElements":[{"id":"t_lr","type":"text"},{"id":"a1","type":"arrow"},{"id":"a2","type":"arrow"},{"id":"a3","type":"arrow"},{"id":"a5","type":"arrow"}]},
  {"type":"text","id":"t_lr","x":195,"y":205,"width":150,"height":20,"text":"Light Reactions","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"lr","originalText":"Light Reactions","autoResize":true},

  {"type":"arrow","id":"a1","x":350,"y":225,"width":120,"height":0,"points":[[0,0],[120,0]],"strokeColor":"#1e1e1e","strokeWidth":2,"endArrowhead":"arrow","boundElements":[{"id":"t_a1","type":"text"}]},
  {"type":"text","id":"t_a1","x":390,"y":205,"width":40,"height":20,"text":"ATP","fontSize":14,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"a1","originalText":"ATP","autoResize":true},

  {"type":"rectangle","id":"cc","x":470,"y":190,"width":160,"height":70,"backgroundColor":"#d0bfff","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#8b5cf6","boundElements":[{"id":"t_cc","type":"text"},{"id":"a1","type":"arrow"},{"id":"a4","type":"arrow"},{"id":"a6","type":"arrow"}]},
  {"type":"text","id":"t_cc","x":475,"y":205,"width":150,"height":20,"text":"Calvin Cycle","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"cc","originalText":"Calvin Cycle","autoResize":true},

  {"type":"rectangle","id":"sl","x":10,"y":200,"width":120,"height":50,"backgroundColor":"#fff3bf","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#f59e0b","boundElements":[{"id":"t_sl","type":"text"},{"id":"a2","type":"arrow"}]},
  {"type":"text","id":"t_sl","x":15,"y":210,"width":110,"height":20,"text":"Sunlight","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"sl","originalText":"Sunlight","autoResize":true},

  {"type":"arrow","id":"a2","x":130,"y":225,"width":60,"height":0,"points":[[0,0],[60,0]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":"arrow"},

  {"type":"rectangle","id":"wa","x":200,"y":360,"width":140,"height":50,"backgroundColor":"#a5d8ff","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#4a9eed","boundElements":[{"id":"t_wa","type":"text"},{"id":"a3","type":"arrow"}]},
  {"type":"text","id":"t_wa","x":205,"y":370,"width":130,"height":20,"text":"Water (H2O)","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"wa","originalText":"Water (H2O)","autoResize":true},

  {"type":"arrow","id":"a3","x":270,"y":360,"width":0,"height":-100,"points":[[0,0],[0,-100]],"strokeColor":"#4a9eed","strokeWidth":2,"endArrowhead":"arrow"},

  {"type":"rectangle","id":"co","x":480,"y":360,"width":130,"height":50,"backgroundColor":"#ffd8a8","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#f59e0b","boundElements":[{"id":"t_co","type":"text"},{"id":"a4","type":"arrow"}]},
  {"type":"text","id":"t_co","x":485,"y":370,"width":120,"height":20,"text":"CO2","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"co","originalText":"CO2","autoResize":true},

  {"type":"arrow","id":"a4","x":545,"y":360,"width":0,"height":-100,"points":[[0,0],[0,-100]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":"arrow"},

  {"type":"rectangle","id":"ox","x":540,"y":100,"width":100,"height":40,"backgroundColor":"#ffc9c9","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#ef4444","boundElements":[{"id":"t_ox","type":"text"},{"id":"a5","type":"arrow"}]},
  {"type":"text","id":"t_ox","x":545,"y":105,"width":90,"height":20,"text":"O2","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"ox","originalText":"O2","autoResize":true},

  {"type":"arrow","id":"a5","x":310,"y":190,"width":230,"height":-50,"points":[[0,0],[230,-50]],"strokeColor":"#ef4444","strokeWidth":2,"endArrowhead":"arrow"},

  {"type":"rectangle","id":"gl","x":690,"y":195,"width":120,"height":60,"backgroundColor":"#c3fae8","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#22c55e","boundElements":[{"id":"t_gl","type":"text"},{"id":"a6","type":"arrow"}]},
  {"type":"text","id":"t_gl","x":695,"y":210,"width":110,"height":25,"text":"Glucose","fontSize":18,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"gl","originalText":"Glucose","autoResize":true},

  {"type":"arrow","id":"a6","x":630,"y":225,"width":60,"height":0,"points":[[0,0],[60,0]],"strokeColor":"#22c55e","strokeWidth":2,"endArrowhead":"arrow"},

  {"type":"ellipse","id":"sun","x":30,"y":110,"width":50,"height":50,"backgroundColor":"#fff3bf","fillStyle":"solid","strokeColor":"#f59e0b","strokeWidth":2},
  {"type":"arrow","id":"r1","x":55,"y":108,"width":0,"height":-14,"points":[[0,0],[0,-14]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":null,"startArrowhead":null},
  {"type":"arrow","id":"r2","x":55,"y":162,"width":0,"height":14,"points":[[0,0],[0,14]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":null,"startArrowhead":null},
  {"type":"arrow","id":"r3","x":28,"y":135,"width":-14,"height":0,"points":[[0,0],[-14,0]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":null,"startArrowhead":null},
  {"type":"arrow","id":"r4","x":82,"y":135,"width":14,"height":0,"points":[[0,0],[14,0]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":null,"startArrowhead":null}
]

---

Example 3: Sequence Diagram (UML-style)

Demonstrates a sequence diagram with actors, dashed lifelines, and message arrows.

[
  {"type":"text","id":"title","x":200,"y":15,"text":"MCP Apps -- Sequence Flow","fontSize":24,"fontFamily":1,"strokeColor":"#1e1e1e","originalText":"MCP Apps -- Sequence Flow","autoResize":true},

  {"type":"rectangle","id":"uHead","x":60,"y":60,"width":100,"height":40,"backgroundColor":"#a5d8ff","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#4a9eed","strokeWidth":2,"boundElements":[{"id":"t_uHead","type":"text"}]},
  {"type":"text","id":"t_uHead","x":65,"y":65,"width":90,"height":20,"text":"User","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"uHead","originalText":"User","autoResize":true},

  {"type":"arrow","id":"uLine","x":110,"y":100,"width":0,"height":400,"points":[[0,0],[0,400]],"strokeColor":"#b0b0b0","strokeWidth":1,"strokeStyle":"dashed","endArrowhead":null},

  {"type":"rectangle","id":"aHead","x":230,"y":60,"width":100,"height":40,"backgroundColor":"#d0bfff","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#8b5cf6","strokeWidth":2,"boundElements":[{"id":"t_aHead","type":"text"}]},
  {"type":"text","id":"t_aHead","x":235,"y":65,"width":90,"height":20,"text":"Agent","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"aHead","originalText":"Agent","autoResize":true},

  {"type":"arrow","id":"aLine","x":280,"y":100,"width":0,"height":400,"points":[[0,0],[0,400]],"strokeColor":"#b0b0b0","strokeWidth":1,"strokeStyle":"dashed","endArrowhead":null},

  {"type":"rectangle","id":"sHead","x":420,"y":60,"width":130,"height":40,"backgroundColor":"#ffd8a8","fillStyle":"solid","roundness":{"type":3},"strokeColor":"#f59e0b","strokeWidth":2,"boundElements":[{"id":"t_sHead","type":"text"}]},
  {"type":"text","id":"t_sHead","x":425,"y":65,"width":120,"height":20,"text":"Server","fontSize":16,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"sHead","originalText":"Server","autoResize":true},

  {"type":"arrow","id":"sLine","x":485,"y":100,"width":0,"height":400,"points":[[0,0],[0,400]],"strokeColor":"#b0b0b0","strokeWidth":1,"strokeStyle":"dashed","endArrowhead":null},

  {"type":"arrow","id":"m1","x":110,"y":150,"width":170,"height":0,"points":[[0,0],[170,0]],"strokeColor":"#1e1e1e","strokeWidth":2,"endArrowhead":"arrow","boundElements":[{"id":"t_m1","type":"text"}]},
  {"type":"text","id":"t_m1","x":165,"y":130,"width":60,"height":20,"text":"request","fontSize":14,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"m1","originalText":"request","autoResize":true},

  {"type":"arrow","id":"m2","x":280,"y":200,"width":205,"height":0,"points":[[0,0],[205,0]],"strokeColor":"#8b5cf6","strokeWidth":2,"endArrowhead":"arrow","boundElements":[{"id":"t_m2","type":"text"}]},
  {"type":"text","id":"t_m2","x":352,"y":180,"width":60,"height":20,"text":"tools/call","fontSize":14,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"m2","originalText":"tools/call","autoResize":true},

  {"type":"arrow","id":"m3","x":485,"y":260,"width":-205,"height":0,"points":[[0,0],[-205,0]],"strokeColor":"#f59e0b","strokeWidth":2,"endArrowhead":"arrow","strokeStyle":"dashed","boundElements":[{"id":"t_m3","type":"text"}]},
  {"type":"text","id":"t_m3","x":352,"y":240,"width":60,"height":20,"text":"result","fontSize":14,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"m3","originalText":"result","autoResize":true},

  {"type":"arrow","id":"m4","x":280,"y":320,"width":-170,"height":0,"points":[[0,0],[-170,0]],"strokeColor":"#8b5cf6","strokeWidth":2,"endArrowhead":"arrow","strokeStyle":"dashed","boundElements":[{"id":"t_m4","type":"text"}]},
  {"type":"text","id":"t_m4","x":165,"y":300,"width":60,"height":20,"text":"response","fontSize":14,"fontFamily":1,"strokeColor":"#1e1e1e","textAlign":"center","verticalAlign":"middle","containerId":"m4","originalText":"response","autoResize":true}
]

---

Common Mistakes to Avoid

• Do NOT use `"label"` property -- this is the #1 mistake. It is NOT part of the Excalidraw file format and will be silently ignored, producing blank shapes with no visible text. Always use container binding (containerId + boundElements) as shown in the examples above.
• Every bound text needs both sides linked -- the shape needs boundElements: [{"id": "t_xxx", "type": "text"}] AND the text needs containerId: "shape_id". If either is missing, the binding won't work.
• Include `originalText` and `autoResize: true` on all text elements -- Excalidraw uses these for proper text reflow.
• Include `fontFamily: 1` on all text elements -- without it, text may not render with the expected hand-drawn font.
• Elements overlap when y-coordinates are close -- always check that text, boxes, and labels don't stack on top of each other
• Arrow labels need space -- long labels like "ATP + NADPH" overflow short arrows. Keep labels short or make arrows wider
• Center titles relative to the diagram -- estimate total width and center the title text over it
• Draw decorations LAST -- cute illustrations (sun, stars, icons) should appear at the end of the array so they're drawn on top