svelte-patterns

name: svelte-patterns description: Svelte 5 runes, component patterns, template directives for Aegis renderer. Use when creating or editing .svelte files.

Svelte 5 Patterns for Aegis

Runes

• $state() for reactive state
• $derived() for computed values
• $effect() for side effects (replaces onMount for reactive deps)
• $props() for component props with defaults
• $bindable() for two-way binding

Component Patterns

• One component per file, max 300 lines
• Props interface at top: let { prop1 = default, prop2 } = $props()
• Event dispatch via callback props, not createEventDispatcher
• Slots via {#snippet} and {@render}

Template Directives

• {#if}/{:else if}/{:else} — conditional rendering
• {#each items as item (item.id)} — keyed lists
• {#await promise} — async data
• use:action — Svelte actions for DOM manipulation
• transition:fade|slide — built-in transitions (GPU only)

For latest Svelte 5 API: use Context7 MCP → @sveltejs/svelte docs