packages

name: packages description: Retend package development rules for starter projects. Use for app code, routing, async state, retend-web features, and code review.

Packages

Use this skill for any Retend application work in this project.

Prefer retrieval-led reasoning. Read the smallest relevant file instead of relying on memory.

Start Here

Read these first:

1. react-migration-patterns.md
2. jsx-reactivity-patterns.md
3. common-anti-patterns.md

Then load only the topic you need:

• derived-cells-complete-guide.md
• control-flow-patterns.md
• component-structure-patterns.md
• routing-patterns.md
• _quick-reference.md

Non-Negotiable Rules

• Do not import from react or react-dom.
• Do not use React hooks or dependency arrays.
• Do not call .get() in JSX. Pass Cells directly.
• Do not use ternaries, &&, ||, or .map() in JSX. Use If, For, Switch, and Await.
• Keep Cell.derived() and Cell.derivedAsync() pure.
• Use array or object syntax for dynamic class values.
• Merge component classes with array syntax.
• Use Link and router.navigate() for internal navigation.
• Handle pending and error states for async work.

Review Checklist

Use this when auditing or refactoring code:

1. Reactivity: no .get() in JSX, no manual snapshot rendering.
2. Async: use derivedAsync, task, and Await instead of manual .then() plus .set().
3. Control flow: use If, For, and Switch instead of inline operators.
4. Structure: PascalCase components, destructure props in the body, hoist handlers.
5. Web rules: camelCase events, correct class syntax, safe class merging.
6. Side effects: no side effects in derived cells.

References

• references/cells-api.md
• references/control-flow.md
• references/scopes.md
• references/element-references.md
• references/retend-utils.md
• references/web-setup.md
• references/attributes-and-events.md
• references/event-modifiers.md
• references/web-components.md
• references/hydration.md
• references/advanced-components.md

Rules

• rules/_index.md is the central rule index.
• Use the individual files in rules/ only when you need a specific rule or fix.