---

name: cytoscape description: Master Cytoscape.js for graph visualization, including Svelte 5 integration, sci-fi styling, custom layouts, and interaction patterns. Use when building relationship maps, node-link diagrams, or interactive network visualizations.

Cytoscape Graph Visualization

Master the art of creating high-performance, aesthetically striking network visualizations using Cytoscape.js, with a focus on Svelte 5 integration and the "Codex Arcana" sci-fi aesthetic.

Core Patterns

1. Svelte 5 Integration

Manage Cytoscape lifecycle and reactivity using Svelte 5 $effect and onMount.

<script lang="ts">
  import { onMount, onDestroy } from 'svelte';
  import cytoscape, { type Core } from 'cytoscape';

  let container: HTMLElement;
  let cy: Core | undefined = $state();
  let { elements } = $props();

  onMount(() => {
    cy = cytoscape({
      container,
      elements,
      style: [ /* styles */ ],
      layout: { name: 'cose' }
    });
  });

  onDestroy(() => {
    cy?.destroy();
  });

  // Reactive updates
  $effect(() => {
    if (cy && elements) {
      cy.elements().remove();
      cy.add(elements);
      cy.layout({ name: 'cose', animate: true }).run();
    }
  });
</script>

<div bind:this={container} class="w-full h-full"></div>

2. Sci-Fi "Terminal" Styling

Embrace a high-contrast, glowing aesthetic. Use dark backgrounds with vibrant green or amber accents.

Feature	Pattern
Node Shape	round-rectangle or diamond for sci-fi feel.
Node Label	Use text-valign: bottom and text-margin-y for a data-readout look.
Edge Style	bezier curves with triangle arrows. Keep lines thin and subtle.
Overlays	Use overlay-color and overlay-opacity for glowing selection effects.

Example Sci-Fi Style:

const SCIFI_STYLE = [
  {
    selector: "node",
    style: {
      "background-color": "#022c22",
      "border-width": 1,
      "border-color": "#15803d",
      label: "data(label)",
      color: "#86efac",
      "font-family": "Inter, monospace",
      "font-size": 10,
      "text-transform": "uppercase",
    },
  },
  {
    selector: "edge",
    style: {
      "line-color": "#14532d",
      "target-arrow-shape": "triangle",
      "curve-style": "bezier",
      opacity: 0.6,
    },
  },
];

3. Layout Strategies

• Cose: Good for organic, balanced layouts.
• Circle/GridLayout: Use for structured overviews or specific groupings.
• Fcose/Cola: Advanced force-directed layouts for complex networks (require plugins).
• Manual: Use metadata.coordinates if entities have fixed positions.

Interaction Patterns

Selection & Focus

Animate the view when a node is selected to provide feedback.

cy.on("tap", "node", (evt) => {
  const node = evt.target;
  cy.animate({
    center: { eles: node },
    zoom: 1.5,
    duration: 500,
    easing: "ease-out-cubic",
  });
});

Connection Management

Implement a "Connect Mode" to allow users to link nodes visually.

• Tap Source -> Tap Target -> Save relationship.
• Visual feedback via classes (e.g., .selected-source).

Performance Guidelines

1. Batch Updates: Use cy.batch() when performing many operations.
2. Selective Layouts: Only run layouts when elements change significantly, not on every prop update.
3. Hardware Acceleration: Cytoscape uses Canvas, which is generally performant, but keep texture usage low.

Best Practices

1. Lifecycle Management: Always destroy() the instance in onDestroy.
2. Viewport Handling: Use cy.fit() and cy.resize() to ensure the graph looks good on all screens.
3. Data Transformation: Use a separate Transformer utility to map domain objects (Entities) to Cytoscape elements.
4. Overlay Elements: Use HTML/CSS overlays for UI (zoom controls, legends) instead of rendering them in the Canvas.