svelte

Coding rules for Svelte, a framework for building web interfaces with reusable components, including its SvelteKit application framework.

In plain words
What is it for?
Use them when creating or reviewing Svelte components, stores, events, pages, forms, loading states, transitions, and animations.
Why use it?
They help keep components, shared state, forms, routing, and reactive updates consistent and avoid unnecessary browser work.

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/rilldata/rill/svelte
Clone the repo
git clone --depth 1 https://github.com/rilldata/rill

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 465 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00000 $0.00465
Opus 5 $0.00000 $0.00233
Sonnet 5 $0.00000 $0.00093
Haiku 4.5 $0.00000 $0.00047

Measured yesterday against content hash 3c03d53ba3d4, 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

Copies of this mod

6 near-identical copies found in the catalogue:

  • svelte — 91% identical, 21 lines differ
  • svelte — 91% identical, 21 lines differ
  • svelte — 91% identical, 20 lines differ
  • svelte — 91% identical, 21 lines differ
  • svelte — 91% identical, 21 lines differ
  • svelte — 88% identical, 21 lines differ
.cursor/rules/svelte.mdc · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

Component Events

  • Avoid using createDispatchEvent and use callback props for handling component events

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

Read the full file on GitHub · 103 lines

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 · 103 lines · 0 tokens per session scan A 3c03d53ba3d4

Subscribe to this mod's changes

svelte is a cursor rule published in the GitHub repository rilldata/rill (2,853 stars, last pushed 3d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 465 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.