svelte

A set of coding rules for Svelte, a framework for building web interfaces with components. It covers component structure, TypeScript, reactive data, state, routing, forms, loading, errors and performance.

In plain words
What is it for?
Use it when creating or reviewing Svelte or SvelteKit components, routes, forms, stores, animations and asynchronous UI states.
Why use it?
It gives an agent consistent guidance for writing and organizing Svelte application code. This can reduce common mistakes in components, shared state and page behavior.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/mitas/cursor-rules/svelte
Clone the repo
git clone --depth 1 https://github.com/mitas/cursor-rules

Made for: Cursor.

Per session 432 This file is loaded in full into every session.
When invoked 432 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin 91% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00432 $0.00432
Opus 5 $0.00216 $0.00216
Sonnet 5 $0.00086 $0.00086
Haiku 4.5 $0.00043 $0.00043

Measured yesterday against content hash 511fbf04344a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

svelte scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

91% identical to svelte — 21 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.cursor/rules/svelte.mdc · 86 lines

What it actually says


description: Svelte best practices and patterns for modern web applications globs: /*.svelte, src//.ts, src/**/.js

Svelte Best Practices

Component Structure

  • Keep components small and focused
  • Use proper TypeScript integration
  • Implement proper props typing
  • Use proper event dispatching
  • Keep markup clean and readable
  • Use proper slot implementation

Reactivity

  • Use proper reactive declarations
  • Implement proper stores
  • Use proper reactive statements
  • Handle derived values properly
  • Use proper lifecycle functions
  • Implement proper bindings

State Management

  • Use proper Svelte stores
  • Keep stores modular
  • Use proper derived stores
  • Implement proper actions
  • Handle async state properly
  • Use proper store subscriptions

Performance

  • Use proper component lazy loading
  • Implement proper transitions
  • Use proper animations
  • Avoid unnecessary reactivity
  • Use proper event forwarding
  • Implement proper key blocks

Routing

  • Use SvelteKit for routing
  • Implement proper layouts
  • Use proper route parameters
  • Handle loading states properly
  • Implement proper error pages
  • Use proper navigation methods

Forms

  • Use proper form bindings
  • Implement proper validation
  • Handle form submission properly
  • Show proper loading states
  • Use proper error handling
  • Implement proper form reset

TypeScript Integration

  • Use proper component types
  • Implement proper prop types
  • Use proper event types
  • Handle proper type inference
  • Use proper store types
  • Implement proper action types

Testing

  • Write proper unit tests
  • Implement proper component tests
  • Use proper testing libraries
  • Test stores properly
  • Implement proper mocking
  • Test async operations

Best Practices

  • Follow Svelte style guide
  • Use proper naming conventions
  • Keep components organized
  • Implement proper error handling
  • Use proper event handling
  • Document complex logic

Build and Tooling

  • Use Vite for development
  • Configure proper build setup
  • Use proper environment variables
  • Implement proper code splitting
  • Use proper asset handling
  • Configure proper optimization
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 86 lines · 432 tokens per session scan A 511fbf04344a

Subscribe to this mod's changes

svelte is a cursor rule published in the GitHub repository mitas/cursor-rules (2 stars, last pushed 1y ago), licensed MIT. It adds 432 tokens to every session, about $0.0022 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to svelte, differing in 21 lines, and is treated as a copy.