excalidraw-diagrams

Excalidraw Diagram Guidelines

These rules produce clean, readable, customer-facing diagrams embedded as inline SVG in the Tigris docs site.

CRITICAL — Read Before Writing Any Diagram

NEVER use label properties on shapes. This is the #1 source of broken diagrams. The label property causes text to overflow and clip outside boxes. Always create a separate text element positioned inside the shape. See the example below.

Embedding Pattern

Diagrams are embedded as React components that render inline SVG. Each diagram has three parts:

1. JSON data file in src/components/diagrams/data/<name>.json — an array of Excalidraw-style element objects
2. Wrapper component in src/components/diagrams/<Name>Diagram.tsx — thin wrapper that imports the JSON and passes it to ExcalidrawDiagram
3. MDX import in the doc page — imports the wrapper and renders it inside a <div className="mermaid-frame">

Wrapper component template

import React from "react";
import ExcalidrawDiagram from "./ExcalidrawDiagram";
import elements from "./data/<name>.json";

export default function <Name>Diagram() {
  return <ExcalidrawDiagram elements={elements} />;
}

MDX usage

Add a mermaid-syntax HTML comment above the diagram for agent readability, then render the component:

{/_ <!-- Mermaid UML description for AI agents:
graph LR
  A[Component] --> B[Component] --> _/}

<div className="mermaid-frame">
  <NameDiagram />
</div>

JSON Data Format — Correct Example

This shows the RIGHT way to put text inside a box — as a separate text element, not a label:

[
  {
    "type": "rectangle",
    "id": "mybox",
    "x": 50,
    "y": 100,
    "width": 200,
    "height": 55,
    "backgroundColor": "#142229",
    "fillStyle": "solid",
    "roundness": { "type": 3 },
    "strokeColor": "#2a4050",
    "strokeWidth": 2
  },
  {
    "type": "text",
    "id": "myboxlbl",
    "x": 75,
    "y": 113,
    "text": "My Label",
    "fontSize": 16,
    "fontFamily": 1,
    "strokeColor": "#c8d6de"
  }
]

Key points:

• The rectangle has NO label property
• The text element is positioned ~25px inward from the box edges
• fontFamily: 1 is set on every text element (Virgil hand-drawn font)
• Text x/y places the top-left of the first line of text

Multi-line text

Use \n in the text field. The renderer splits on newlines and renders <tspan> elements. Account for ~1.3× fontSize vertical spacing per line.

Font

• Always set fontFamily: 1 on every text element. This is Excalidraw's hand-drawn font (Virgil). Without it, text renders in a mismatched default.

Text Sizing

• The Virgil font renders significantly wider than you'd expect from the pixel coordinates. Always overestimate the space text needs by ~40%.
• Make boxes wide enough to hold the text with at least 25px padding from all edges.

Spacing Between Elements

• Minimum 160px horizontal gap between connected boxes. This gives arrow labels room to breathe.
• Minimum 125px vertical gap between connected boxes.
• Arrow labels must be placed at least 25px away from the arrow line — above for forward arrows, below for return arrows.
• Never place a text label between two parallel arrows. Put labels on the outer sides (above the top arrow, below the bottom arrow).

Arrow Labels

• Place labels as separate text elements above or below arrows, never overlapping them. Do NOT use label on arrows either.
• For bidirectional flows (request → / ← response), stagger the arrows vertically with ~50px gap and put labels on opposite sides.

Zone Labels

• Place zone labels (for dashed-border grouping boxes) in the upper-left corner of the zone, ~15px inward from the top-left edges.
• Use a smaller font size (14–16px) and secondary text color.

Box Internal Padding

• Text inside boxes should have at least 25px padding from all edges.
• For multi-line box content (title + subtitle), leave 30px between lines.

Styling

• The ExcalidrawDiagram component provides its own dark background (#0e1920) and border-radius. Do NOT add borders to the SVG or to the .mermaid-frame wrapper — the diagram is self-contained.
• Do NOT add borders, background colors, or border-radius via inline styles on the SVG element.

Color Scheme (Tigris Dark Theme)

Use this palette to match the Tigris brand:

Background:        #0e1920 (SVG bg, set by component)
Node fill:         #142229 (boxes, containers)
Zone backgrounds:  #142229 at opacity 40 (dashed grouping zones)
Borders:           #1e3340 (zones), #2a4050 (node borders)
Primary text:      #c8d6de
Secondary text:    #8fa3b0
Primary accent:    #62FEB5 (Tigris green — highlights, key elements)
Dark on accent:    #0A171E (text on green backgrounds)

Additional accent colors:
  Steel blue:  #5BA4CF (secondary flows, metadata, gRPC, gossip)
  Sandstone:   #CF8E5B (warnings, cache miss)
  Muted coral: #CF5B5B (errors)

Do NOT use saturated purple (#8b5cf6), bright amber (#f59e0b), or
bright red (#ef4444) — they clash with the cool-toned palette.

Layout Pattern

• Use dashed stroke zones to group related components (e.g., "Your Infrastructure" vs "Tigris Cloud")
• Use numbered step badges (filled circles with numbers) to guide reading order
• Include a Legend box with sample arrows explaining line styles (solid = request, dashed = response, colored = upstream fetch)
• Add an explanatory callout box (dashed border) for key performance facts

Verification

After creating or modifying a diagram, run the dev server (npm start) and visually check the page in the browser. Look for:

1. Text clipping or cutoff at box edges
2. Arrow lines crossing over text labels
3. Sufficient contrast (text readable against backgrounds)
4. All elements visible and nothing overlapping
5. Multi-line text rendering correctly (not as a single line)

Common Mistakes to Avoid

These are listed in order of severity. Every one of these has caused a broken diagram in the past:

1. Do not use label property on ANY element — text clips and overflows. Always use separate text elements. This applies to rectangles, diamonds, ellipses, AND arrows.
2. Do not forget fontFamily: 1 — causes wrong font rendering on every text element.
3. Do not make boxes too narrow — Virgil font is ~40% wider than you expect. A 6-character label needs a box at least 150px wide.
4. Do not place zone labels at the bottom — convention is upper-left corner.
5. Do not add borders to the SVG or wrapper — the component handles styling.
6. Do not place text between two parallel arrows — always gets obscured.
7. Do not use gaps under 120px between connected elements — labels collide.
8. Do not change colors when asked to fix spacing — always preserve the approved palette.