solid-js

A set of conventions for SolidJS, a JavaScript framework that updates only the parts of a page affected by changed data. It covers signals, components, asynchronous data, and state management.

In plain words
What is it for?
Use it when creating or reviewing SolidJS components, signals, stores, contexts, conditional views, asynchronous resources, and related tests.
Why use it?
It prevents mistakes that break SolidJS’s reactive updates, such as treating components like React render functions or destructuring reactive properties.

Cursor rule

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/nedcodes-ok/cursorrules-collection/solid-js
Clone the repo
git clone --depth 1 https://github.com/nedcodes-ok/cursorrules-collection
Per session 444 This file is loaded in full into every session.
When invoked 444 The same file — it is already loaded in full.
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 $0.00444 $0.00444
Opus 5 $0.00222 $0.00222
Sonnet 5 $0.00089 $0.00089
Haiku 4.5 $0.00044 $0.00044

Measured yesterday against content hash ac217360f4b3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

solid-js 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.

rules-mdc/frameworks/solid-js.mdc · 50 lines

What it actually says

SolidJS Cursor Rules

You are an expert SolidJS developer. Follow these rules:

Reactivity

  • Signals are the foundation: createSignal for state, createMemo for derived
  • Components run once — they are setup functions, not render functions
  • Never destructure props — it breaks reactivity. Use props.name or mergeProps
  • Access signals by calling them: count() not count
  • createEffect for side effects that depend on reactive values

Components

  • Return JSX from components — no virtual DOM, real DOM operations
  • Use instead of ternary for conditional rendering
  • Use instead of .map() — it tracks by reference efficiently
  • / for multi-branch conditionals
  • at feature boundaries with fallback UI

State Management

  • createSignal for local state
  • createStore for nested/complex objects — it provides deep reactivity
  • Context with createContext for dependency injection
  • Avoid global mutable state — signals in context are the answer
  • Use produce() for immer-like store mutations

Resources

  • createResource for async data fetching with Suspense support
  • Resources integrate with — always wrap data components
  • Provide source signal to createResource for reactive refetching
  • Use initialValue to avoid undefined checks

Performance

  • SolidJS is fast by default — dont optimize prematurely
  • Batch multiple signal updates with batch() when needed
  • Use untrack() to read signals without subscribing
  • Lazy-load components with lazy() for code splitting

JSX Differences from React

  • class not className, for not htmlFor
  • Style objects use CSS property names: { "background-color": "red" }
  • Event handlers are lowercase: onclick not onClick
  • Refs via let ref; — assigned synchronously
  • No key prop on — it tracks by reference automatically
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 · 50 lines · 444 tokens per session scan A ac217360f4b3

Subscribe to this mod's changes

solid-js is a cursor rule published in the GitHub repository nedcodes-ok/cursorrules-collection (37 stars, last pushed 6mo ago), licensed MIT. It adds 444 tokens to every session, about $0.0022 per session on Opus 5. 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.