Excalidraw CLI — Agent Skill

Create hand-drawn diagrams from JSON using excalidraw-cli. Outputs .excalidraw files and shareable URLs.

Quick Start

# Create diagram from inline JSON
excalidraw create --json '[...elements...]' -o diagram.excalidraw

# Export to shareable URL
excalidraw export diagram.excalidraw
# → https://excalidraw.com/#json=abc,key

# Create from file
excalidraw create elements.json -o diagram.excalidraw

# Pipe from stdin
echo '[...elements...]' | excalidraw create -o diagram.excalidraw

Built-in Defaults (skip these in JSON)

The CLI auto-applies these so you write less JSON:

Override any default by setting it explicitly.

Element Types

Shapes (rectangle, ellipse, diamond)

Minimal — just type, id, position, size:

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

Filled:

{ "type": "rectangle", "id": "r1", "x": 100, "y": 100, "width": 200, "height": 100, "backgroundColor": "#a5d8ff", "fillStyle": "solid" }

Labels (text inside shapes)

Use the label shorthand on any shape — the CLI auto-expands it into proper bound text elements:

{ "type": "rectangle", "id": "b1", "x": 100, "y": 100, "width": 200, "height": 80, "backgroundColor": "#a5d8ff", "fillStyle": "solid", "label": { "text": "My Label", "fontSize": 20 } }

Works on rectangle, ellipse, diamond, and arrow. Optional label properties: fontSize (default 20), fontFamily, strokeColor.

For dark mode, set text color via strokeColor in the label:

"label": { "text": "Hello", "strokeColor": "#e5e5e5" }

Standalone Text (titles, annotations)

{ "type": "text", "id": "t1", "x": 100, "y": 50, "text": "Diagram Title", "fontSize": 28 }

To center text at position cx: set x = cx - (text.length × fontSize × 0.5) / 2

Arrows

Basic 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 the arrow's x, y
• endArrowhead: null | "arrow" | "bar" | "dot" | "triangle"

Arrow Bindings (connect shapes)

{
  "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] }
}

fixedPoint [x, y] — normalized position on the shape edge:

• Right: [1, 0.5]
• Left: [0, 0.5]
• Top: [0.5, 0]
• Bottom: [0.5, 1]

When binding arrows, also add the arrow to each shape's boundElements:

{ "type": "rectangle", "id": "b1", ..., "boundElements": [{ "id": "b1_t", "type": "text" }, { "id": "a1", "type": "arrow" }] }

Arrow Labels

Use the same label shorthand on arrows:

{ "type": "arrow", "id": "a1", "x": 300, "y": 150, "width": 150, "height": 0, "points": [[0,0],[150,0]], "endArrowhead": "arrow", "label": { "text": "connects", "fontSize": 16 } }

Camera (Viewport)

Controls what's visible when opened. MUST be 4:3 aspect ratio:

{ "type": "cameraUpdate", "width": 800, "height": 600, "x": 50, "y": 20 }

Set x, y to the top-left of your content area (with ~50px padding).

Color Palette

Shape Fills (pastel backgrounds)

Background Zones (use opacity: 30)

Primary Stroke/Text Colors

#4a9eed blue, #f59e0b amber, #22c55e green, #ef4444 red, #8b5cf6 purple, #ec4899 pink, #06b6d4 cyan, #84cc16 lime

Drawing Order

Array order = z-order (first = back, last = front). Emit progressively:

camera → background zones → shape1 → shape1_text → arrow1 → arrow1_text → shape2 → ...

BAD: all rectangles → all texts → all arrows GOOD: shape → its text → its arrows → next shape → its text → ...

Font Size Rules

• 28+ for diagram titles
• 20 for shape labels and headings
• 16-18 for body text, descriptions
• 14 minimum (secondary annotations only)
• Never below 14

Element Sizing

• Minimum shape: 120×60 for labeled shapes
• 20-30px gaps between elements minimum
• Prefer fewer, larger elements over many tiny ones

Pseudo-Elements

cameraUpdate (viewport control)

{ "type": "cameraUpdate", "width": 800, "height": 600, "x": 0, "y": 0 }

delete (remove elements by id)

{ "type": "delete", "ids": "b2,a1,t3" }

restoreCheckpoint (build on previous diagram)

{ "type": "restoreCheckpoint", "id": "checkpoint-id-here" }

Checkpoints

excalidraw checkpoint list
excalidraw checkpoint save mydiagram diagram.excalidraw
excalidraw checkpoint load mydiagram -o restored.excalidraw
excalidraw checkpoint remove mydiagram

Use restoreCheckpoint in JSON to build on a previous diagram, and delete to remove elements from it.

Dark Mode

Add a massive dark background as the FIRST element:

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

Dark fills: #1e3a5f blue, #1a4d2e green, #2d1b69 purple, #5c3d1a orange, #5c1a1a red, #1a4d4d teal Text on dark: #e5e5e5 primary, #a0a0a0 muted — set via strokeColor on text elements.

Tips

• No emoji in text — Excalidraw's font doesn't render them
• Minimum text color on white: #757575
• Always set fillStyle: "solid" when using backgroundColor
• Arrow points are offsets from the arrow's x, y, not absolute coordinates
• Arrow width/height should match the bounding box of your points

Examples

Example 1: Simple Flow (3 connected boxes)

Minimal JSON — no roughness, roundness, or fontFamily needed (all defaults). Dark mode with label shorthand.

excalidraw create --json '[
  { "type": "cameraUpdate", "width": 1200, "height": 900, "x": 0, "y": 100 },
  { "type": "rectangle", "id": "darkbg", "x": -4000, "y": -3000, "width": 10000, "height": 7500, "backgroundColor": "#1e1e2e", "fillStyle": "solid", "strokeColor": "transparent", "strokeWidth": 0 },
  { "type": "rectangle", "id": "b1", "x": 60, "y": 350, "width": 220, "height": 90, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "strokeColor": "#4a9eed", "label": { "text": "Request", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }] },
  { "type": "arrow", "id": "a1", "x": 280, "y": 395, "width": 200, "height": 0, "points": [[0,0],[200,0]], "endArrowhead": "arrow", "strokeColor": "#4a9eed", "startBinding": { "elementId": "b1", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "b2", "fixedPoint": [0, 0.5] }, "label": { "text": "process", "strokeColor": "#a0a0a0" } },
  { "type": "rectangle", "id": "b2", "x": 500, "y": 350, "width": 220, "height": 90, "backgroundColor": "#5c3d1a", "fillStyle": "solid", "strokeColor": "#f59e0b", "label": { "text": "Server", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }, { "id": "a2", "type": "arrow" }] },
  { "type": "arrow", "id": "a2", "x": 720, "y": 395, "width": 200, "height": 0, "points": [[0,0],[200,0]], "endArrowhead": "arrow", "strokeColor": "#22c55e", "startBinding": { "elementId": "b2", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "b3", "fixedPoint": [0, 0.5] }, "label": { "text": "respond", "strokeColor": "#a0a0a0" } },
  { "type": "rectangle", "id": "b3", "x": 940, "y": 350, "width": 220, "height": 90, "backgroundColor": "#1a4d2e", "fillStyle": "solid", "strokeColor": "#22c55e", "label": { "text": "Response", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a2", "type": "arrow" }] }
]' -o flow.excalidraw

Example 2: Architecture Diagram (with zones)

excalidraw create --json '[
  { "type": "cameraUpdate", "width": 1200, "height": 900, "x": 0, "y": 0 },
  { "type": "rectangle", "id": "darkbg", "x": -4000, "y": -3000, "width": 10000, "height": 7500, "backgroundColor": "#1e1e2e", "fillStyle": "solid", "strokeColor": "transparent", "strokeWidth": 0 },
  { "type": "text", "id": "title", "x": 380, "y": 20, "text": "Web App Architecture", "fontSize": 28, "strokeColor": "#e5e5e5" },
  { "type": "rectangle", "id": "zone_fe", "x": 30, "y": 70, "width": 1140, "height": 200, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "opacity": 30, "strokeColor": "transparent" },
  { "type": "text", "id": "zone_fe_t", "x": 50, "y": 80, "text": "Frontend", "fontSize": 16, "strokeColor": "#4a9eed" },
  { "type": "rectangle", "id": "zone_be", "x": 30, "y": 300, "width": 1140, "height": 200, "backgroundColor": "#2d1b69", "fillStyle": "solid", "opacity": 30, "strokeColor": "transparent" },
  { "type": "text", "id": "zone_be_t", "x": 50, "y": 310, "text": "Backend", "fontSize": 16, "strokeColor": "#8b5cf6" },
  { "type": "rectangle", "id": "zone_db", "x": 30, "y": 530, "width": 1140, "height": 200, "backgroundColor": "#1a4d2e", "fillStyle": "solid", "opacity": 30, "strokeColor": "transparent" },
  { "type": "text", "id": "zone_db_t", "x": 50, "y": 540, "text": "Data Layer", "fontSize": 16, "strokeColor": "#22c55e" },
  { "type": "rectangle", "id": "react", "x": 100, "y": 120, "width": 200, "height": 80, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "strokeColor": "#4a9eed", "label": { "text": "React App", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }] },
  { "type": "rectangle", "id": "cdn", "x": 500, "y": 120, "width": 200, "height": 80, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "strokeColor": "#4a9eed", "label": { "text": "CDN", "strokeColor": "#e5e5e5" } },
  { "type": "rectangle", "id": "auth", "x": 900, "y": 120, "width": 200, "height": 80, "backgroundColor": "#5c1a1a", "fillStyle": "solid", "strokeColor": "#ef4444", "label": { "text": "Auth (OAuth)", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a3", "type": "arrow" }] },
  { "type": "arrow", "id": "a1", "x": 200, "y": 200, "width": 0, "height": 150, "points": [[0,0],[0,150]], "endArrowhead": "arrow", "strokeColor": "#4a9eed", "startBinding": { "elementId": "react", "fixedPoint": [0.5, 1] }, "endBinding": { "elementId": "api", "fixedPoint": [0.5, 0] }, "label": { "text": "REST API", "strokeColor": "#a0a0a0" } },
  { "type": "rectangle", "id": "api", "x": 100, "y": 360, "width": 200, "height": 80, "backgroundColor": "#2d1b69", "fillStyle": "solid", "strokeColor": "#8b5cf6", "label": { "text": "API Server", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }, { "id": "a2", "type": "arrow" }] },
  { "type": "rectangle", "id": "queue", "x": 500, "y": 360, "width": 200, "height": 80, "backgroundColor": "#5c3d1a", "fillStyle": "solid", "strokeColor": "#f59e0b", "label": { "text": "Job Queue", "strokeColor": "#e5e5e5" } },
  { "type": "rectangle", "id": "worker", "x": 900, "y": 360, "width": 200, "height": 80, "backgroundColor": "#5c3d1a", "fillStyle": "solid", "strokeColor": "#f59e0b", "label": { "text": "Workers", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a3", "type": "arrow" }] },
  { "type": "arrow", "id": "a3", "x": 1000, "y": 200, "width": 0, "height": 150, "points": [[0,0],[0,150]], "endArrowhead": "arrow", "strokeColor": "#ef4444", "startBinding": { "elementId": "auth", "fixedPoint": [0.5, 1] }, "endBinding": { "elementId": "worker", "fixedPoint": [0.5, 0] } },
  { "type": "arrow", "id": "a2", "x": 200, "y": 440, "width": 0, "height": 150, "points": [[0,0],[0,150]], "endArrowhead": "arrow", "strokeColor": "#8b5cf6", "startBinding": { "elementId": "api", "fixedPoint": [0.5, 1] }, "endBinding": { "elementId": "pg", "fixedPoint": [0.5, 0] }, "label": { "text": "queries", "strokeColor": "#a0a0a0" } },
  { "type": "rectangle", "id": "pg", "x": 100, "y": 590, "width": 200, "height": 80, "backgroundColor": "#1a4d4d", "fillStyle": "solid", "strokeColor": "#06b6d4", "label": { "text": "PostgreSQL", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a2", "type": "arrow" }] },
  { "type": "rectangle", "id": "redis", "x": 500, "y": 590, "width": 200, "height": 80, "backgroundColor": "#1a4d4d", "fillStyle": "solid", "strokeColor": "#06b6d4", "label": { "text": "Redis Cache", "strokeColor": "#e5e5e5" } },
  { "type": "rectangle", "id": "s3", "x": 900, "y": 590, "width": 200, "height": 80, "backgroundColor": "#1a4d4d", "fillStyle": "solid", "strokeColor": "#06b6d4", "label": { "text": "S3 Storage", "strokeColor": "#e5e5e5" } }
]' -o architecture.excalidraw

Example 3: Decision Flowchart (with diamond)

excalidraw create --json '[
  { "type": "cameraUpdate", "width": 1200, "height": 900, "x": -20, "y": 0 },
  { "type": "rectangle", "id": "darkbg", "x": -4000, "y": -3000, "width": 10000, "height": 7500, "backgroundColor": "#1e1e2e", "fillStyle": "solid", "strokeColor": "transparent", "strokeWidth": 0 },
  { "type": "rectangle", "id": "start", "x": 430, "y": 60, "width": 200, "height": 80, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "strokeColor": "#4a9eed", "label": { "text": "User Login", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }] },
  { "type": "arrow", "id": "a1", "x": 530, "y": 140, "width": 0, "height": 100, "points": [[0,0],[0,100]], "endArrowhead": "arrow", "strokeColor": "#4a9eed", "startBinding": { "elementId": "start", "fixedPoint": [0.5, 1] }, "endBinding": { "elementId": "check", "fixedPoint": [0.5, 0] } },
  { "type": "diamond", "id": "check", "x": 400, "y": 260, "width": 260, "height": 180, "backgroundColor": "#5c3d1a", "fillStyle": "solid", "strokeColor": "#f59e0b", "label": { "text": "Valid\nCredentials?", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }, { "id": "a2", "type": "arrow" }, { "id": "a3", "type": "arrow" }] },
  { "type": "arrow", "id": "a2", "x": 660, "y": 350, "width": 180, "height": 0, "points": [[0,0],[180,0]], "endArrowhead": "arrow", "strokeColor": "#22c55e", "startBinding": { "elementId": "check", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "yes", "fixedPoint": [0, 0.5] }, "label": { "text": "Yes", "strokeColor": "#22c55e" } },
  { "type": "rectangle", "id": "yes", "x": 860, "y": 310, "width": 220, "height": 80, "backgroundColor": "#1a4d2e", "fillStyle": "solid", "strokeColor": "#22c55e", "label": { "text": "Dashboard", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a2", "type": "arrow" }] },
  { "type": "arrow", "id": "a3", "x": 400, "y": 350, "width": 180, "height": 0, "points": [[0,0],[-180,0]], "endArrowhead": "arrow", "strokeColor": "#ef4444", "startBinding": { "elementId": "check", "fixedPoint": [0, 0.5] }, "endBinding": { "elementId": "no", "fixedPoint": [1, 0.5] }, "label": { "text": "No", "strokeColor": "#ef4444" } },
  { "type": "rectangle", "id": "no", "x": 0, "y": 310, "width": 220, "height": 80, "backgroundColor": "#5c1a1a", "fillStyle": "solid", "strokeColor": "#ef4444", "label": { "text": "Error Page", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a3", "type": "arrow" }] }
]' -o flowchart.excalidraw

Example 4: Kitchen Sink (every feature)

Demonstrates: all shape types, label shorthand, arrow bindings + labels, standalone text, background zones, colors, opacity, dark mode, camera, diamond, ellipse.

excalidraw create --json '[
  { "type": "cameraUpdate", "width": 1200, "height": 900, "x": -60, "y": -40 },
  { "type": "rectangle", "id": "darkbg", "x": -4000, "y": -3000, "width": 10000, "height": 7500, "backgroundColor": "#1e1e2e", "fillStyle": "solid", "strokeColor": "transparent", "strokeWidth": 0 },
  { "type": "text", "id": "title", "x": 280, "y": -20, "text": "Kitchen Sink: All Features", "fontSize": 28, "strokeColor": "#e5e5e5" },
  { "type": "rectangle", "id": "zone1", "x": -30, "y": 30, "width": 550, "height": 380, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "opacity": 30, "strokeColor": "transparent" },
  { "type": "text", "id": "zone1_t", "x": -10, "y": 40, "text": "Input Layer", "fontSize": 16, "strokeColor": "#4a9eed" },
  { "type": "rectangle", "id": "zone2", "x": 560, "y": 30, "width": 550, "height": 380, "backgroundColor": "#2d1b69", "fillStyle": "solid", "opacity": 30, "strokeColor": "transparent" },
  { "type": "text", "id": "zone2_t", "x": 580, "y": 40, "text": "Processing Layer", "fontSize": 16, "strokeColor": "#8b5cf6" },
  { "type": "rectangle", "id": "b1", "x": 50, "y": 90, "width": 200, "height": 80, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "strokeColor": "#4a9eed", "label": { "text": "API Gateway", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }] },
  { "type": "ellipse", "id": "e1", "x": 80, "y": 230, "width": 160, "height": 120, "backgroundColor": "#1a4d4d", "fillStyle": "solid", "strokeColor": "#06b6d4", "label": { "text": "Cache\n(Redis)", "fontSize": 18, "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a3", "type": "arrow" }] },
  { "type": "diamond", "id": "d1", "x": 330, "y": 120, "width": 180, "height": 140, "backgroundColor": "#5c3d1a", "fillStyle": "solid", "strokeColor": "#f59e0b", "label": { "text": "Auth\nCheck?", "fontSize": 18, "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a1", "type": "arrow" }, { "id": "a2", "type": "arrow" }, { "id": "a4", "type": "arrow" }] },
  { "type": "arrow", "id": "a1", "x": 250, "y": 130, "width": 80, "height": 60, "points": [[0,0],[80,60]], "endArrowhead": "arrow", "strokeColor": "#4a9eed", "startBinding": { "elementId": "b1", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "d1", "fixedPoint": [0, 0.5] }, "label": { "text": "request", "fontSize": 14, "strokeColor": "#a0a0a0" } },
  { "type": "arrow", "id": "a2", "x": 510, "y": 190, "width": 130, "height": 0, "points": [[0,0],[130,0]], "endArrowhead": "arrow", "strokeColor": "#22c55e", "startBinding": { "elementId": "d1", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "b2", "fixedPoint": [0, 0.5] }, "label": { "text": "valid", "fontSize": 14, "strokeColor": "#22c55e" } },
  { "type": "arrow", "id": "a4", "x": 420, "y": 260, "width": 0, "height": 80, "points": [[0,0],[0,80]], "endArrowhead": "arrow", "strokeColor": "#ef4444", "startBinding": { "elementId": "d1", "fixedPoint": [0.5, 1] }, "endBinding": { "elementId": "err", "fixedPoint": [0.5, 0] }, "label": { "text": "denied", "fontSize": 14, "strokeColor": "#ef4444" } },
  { "type": "rectangle", "id": "err", "x": 340, "y": 340, "width": 160, "height": 60, "backgroundColor": "#5c1a1a", "fillStyle": "solid", "strokeColor": "#ef4444", "label": { "text": "403 Error", "fontSize": 18, "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a4", "type": "arrow" }] },
  { "type": "rectangle", "id": "b2", "x": 660, "y": 150, "width": 200, "height": 80, "backgroundColor": "#2d1b69", "fillStyle": "solid", "strokeColor": "#8b5cf6", "label": { "text": "Controller", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a2", "type": "arrow" }, { "id": "a5", "type": "arrow" }] },
  { "type": "arrow", "id": "a5", "x": 760, "y": 230, "width": 0, "height": 100, "points": [[0,0],[0,100]], "endArrowhead": "arrow", "strokeColor": "#8b5cf6", "startBinding": { "elementId": "b2", "fixedPoint": [0.5, 1] }, "endBinding": { "elementId": "b3", "fixedPoint": [0.5, 0] } },
  { "type": "rectangle", "id": "b3", "x": 660, "y": 340, "width": 200, "height": 80, "backgroundColor": "#1a4d2e", "fillStyle": "solid", "strokeColor": "#22c55e", "label": { "text": "Database", "strokeColor": "#e5e5e5" }, "boundElements": [{ "id": "a5", "type": "arrow" }, { "id": "a3", "type": "arrow" }] },
  { "type": "arrow", "id": "a3", "x": 660, "y": 380, "width": 420, "height": 0, "points": [[0,0],[-420,0]], "endArrowhead": "arrow", "strokeColor": "#06b6d4", "startBinding": { "elementId": "b3", "fixedPoint": [0, 0.5] }, "endBinding": { "elementId": "e1", "fixedPoint": [1, 0.5] }, "label": { "text": "cache result", "fontSize": 14, "strokeColor": "#a0a0a0" } },
  { "type": "text", "id": "note", "x": 600, "y": 460, "text": "All shapes, arrows, zones, and dark mode", "fontSize": 16, "strokeColor": "#a0a0a0" }
]' -o kitchen-sink.excalidraw

Minimal Labeled Box Pattern (copy-paste template)

{ "type": "rectangle", "id": "ID", "x": X, "y": Y, "width": 200, "height": 80, "backgroundColor": "COLOR", "fillStyle": "solid", "label": { "text": "LABEL" } }

Dark mode version:

{ "type": "rectangle", "id": "ID", "x": X, "y": Y, "width": 200, "height": 80, "backgroundColor": "#1e3a5f", "fillStyle": "solid", "strokeColor": "#4a9eed", "label": { "text": "LABEL", "strokeColor": "#e5e5e5" } }

Minimal Arrow Pattern (copy-paste template)

{ "type": "arrow", "id": "AID", "x": X, "y": Y, "width": W, "height": 0, "points": [[0,0],[W,0]], "endArrowhead": "arrow", "startBinding": { "elementId": "FROM", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "TO", "fixedPoint": [0, 0.5] } }

With label:

{ "type": "arrow", "id": "AID", "x": X, "y": Y, "width": W, "height": 0, "points": [[0,0],[W,0]], "endArrowhead": "arrow", "startBinding": { "elementId": "FROM", "fixedPoint": [1, 0.5] }, "endBinding": { "elementId": "TO", "fixedPoint": [0, 0.5] }, "label": { "text": "LABEL", "fontSize": 16 } }

Dark Mode Background (copy-paste template)

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