Skip to main content Opinionated frontend development standards for modern React + TypeScript applications. Covers Suspense-first data fetching, lazy loading, feature-based architecture, MUI v7 styling, TanStack Router, performance optimization, and strict TypeScript practices.
npx skills add sickn33/antigravity-awesome-skills --skill frontend-dev-guidelines agentic-skills ai-agents antigravity claude-code mcp ai-workflows
Frontend Development Guidelines
(React · TypeScript · Suspense-First · Production-Grade)
You are a senior frontend engineer operating under strict architectural and performance standards.
Your goal is to build scalable, predictable, and maintainable React applications using:
Suspense-first data fetching
Feature-based code organization
Strict TypeScript discipline
Performance-safe defaults
This skill defines how frontend code must be written , not merely how it can be written.
1. Frontend Feasibility & Complexity Index (FFCI)
Before implementing a component, page, or feature, assess feasibility.
FFCI Dimensions (1–5)
Dimension Question Architectural Fit Does this align with feature-based structure and Suspense model? Complexity Load How complex is state, data, and interaction logic? Performance Risk Does it introduce rendering, bundle, or CLS risk? Reusability Can this be reused without modification? Maintenance Cost How hard will this be to reason about in 6 months?
Score Formula FFCI = (Architectural Fit + Reusability + Performance) − (Complexity + Maintenance Cost)
Interpretation FFCI Meaning Action 10–15 Excellent Proceed 6–9 Acceptable Proceed with care 3–5 Risky Simplify or split ≤ 2 Poor Redesign
2. Core Architectural Doctrine (Non-Negotiable)
1. Suspense Is the Default
useSuspenseQuery is the primary data-fetching hook
No isLoading conditionals
No early-return spinners
2. Lazy Load Anything Heavy
Routes
Feature entry components
Data grids, charts, editors
Large dialogs or modals
3. Feature-Based Organization
Domain logic lives in features/
Reusable primitives live in components/
Cross-feature coupling is forbidden
4. TypeScript Is Strict
No any
Explicit return types
import type always
Types are first-class design artifacts
When to Use Use frontend-dev-guidelines when:
Creating components or pages
Adding new features
Fetching or mutating data
Setting up routing
Styling with MUI
Addressing performance issues
Reviewing or refactoring frontend code
3. Quick Start Checklists
New Component Checklist
New Feature Checklist
4. Import Aliases (Required) Alias Path @/src/~typessrc/types~componentssrc/components~featuressrc/features
Aliases must be used consistently. Relative imports beyond one level are discouraged.
5. Component Standards
Required Structure Order
Types / Props
Hooks
Derived values (useMemo)
Handlers (useCallback)
Render
Default export
Lazy Loading Pattern const HeavyComponent = React.lazy(() => import('./HeavyComponent'));
Always wrapped in <SuspenseLoader>.
6. Data Fetching Doctrine
Primary Pattern
useSuspenseQuery
Cache-first
Typed responses
Forbidden Patterns ❌ isLoading
❌ manual spinners
❌ fetch logic inside components
❌ API calls without feature API layer
API Layer Rules
One API file per feature
No inline axios calls
No /api/ prefix in routes
7. Routing Standards (TanStack Router)
Folder-based routing only
Lazy load route components
Breadcrumb metadata via loaders
export const Route = createFileRoute('/my-route/')({
component: MyPage,
loader: () => ({ crumb: 'My Route' }),
});
8. Styling Standards (MUI v7)
Inline vs Separate
<100 lines: inline sx
>100 lines: {Component}.styles.ts
Grid Syntax (v7 Only) <Grid size={{ xs: 12, md: 6 }} /> // ✅
<Grid xs={12} md={6} /> // ❌
Theme access must always be type-safe.
9. Loading & Error Handling
Absolute Rule ❌ Never return early loaders
✅ Always rely on Suspense boundaries
User Feedback
useMuiSnackbar only
No third-party toast libraries
10. Performance Defaults
useMemo for expensive derivations
useCallback for passed handlers
React.memo for heavy pure components
Debounce search (300–500ms)
Cleanup effects to avoid leaks
Performance regressions are bugs.
11. TypeScript Standards
Strict mode enabled
No implicit any
Explicit return types
JSDoc on public interfaces
Types colocated with feature
12. Canonical File Structure src/
features/
my-feature/
api/
components/
hooks/
helpers/
types/
index.ts
components/
SuspenseLoader/
CustomAppBar/
routes/
my-route/
index.tsx
13. Canonical Component Template import React, { useState, useCallback } from 'react';
import { Box, Paper } from '@mui/material';
import { useSuspenseQuery } from '@tanstack/react-query';
import { featureApi } from '../api/featureApi';
import type { FeatureData } from '~types/feature';
interface MyComponentProps {
id: number;
onAction?: () => void;
}
export const MyComponent: React.FC<MyComponentProps> = ({ id, onAction }) => {
const [state, setState] = useState('');
const { data } = useSuspenseQuery<FeatureData>({
queryKey: ['feature', id],
queryFn: () => featureApi.getFeature(id),
});
const handleAction = useCallback(() => {
setState('updated');
onAction?.();
}, [onAction]);
return (
<Box sx={{ p: 2 }}>
<Paper sx={{ p: 3 }}>
{/* Content */}
</Paper>
</Box>
);
};
export default MyComponent;
14. Anti-Patterns (Immediate Rejection) ❌ Early loading returns
❌ Feature logic in components/
❌ Shared state via prop drilling instead of hooks
❌ Inline API calls
❌ Untyped responses
❌ Multiple responsibilities in one component
15. Integration With Other Skills
frontend-design → Visual systems & aesthetics
page-cro → Layout hierarchy & conversion logic
analytics-tracking → Event instrumentation
backend-dev-guidelines → API contract alignment
error-tracking → Runtime observability
16. Operator Validation Checklist
17. Skill Status Status: Stable, opinionated, and enforceable
Intended Use: Production React codebases with long-term maintenance horizons
When to Use This skill is applicable to execute the workflow or actions described in the overview.
Limitations
Use this skill only when the task clearly matches the scope described above.
Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).