Frontend Dev Guidelines V2

Frontend Development Guidelines

Overview

This public intake copy packages plugins/antigravity-awesome-skills/skills/frontend-dev-guidelines from https://github.com/sickn33/antigravity-awesome-skills into the native Omni Skills editorial shape without hiding its origin.

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses the external_source block in metadata.json plus ORIGIN.md as the provenance anchor for review.

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. ---

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: 2. Core Architectural Doctrine (Non-Negotiable), 3. Quick Start Checklists, 4. Import Aliases (Required), 5. Component Standards, 6. Data Fetching Doctrine, 8. Styling Standards (MUI v7).

When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

• Creating components or pages
• Adding new features
• Fetching or mutating data
• Setting up routing
• Styling with MUI
• Addressing performance issues

Operating Table

Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Folder-based routing only
2. Lazy load route components
3. Breadcrumb metadata via loaders
4. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task.
5. Read the overview and provenance files before loading any copied upstream support files.
6. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request.
7. Execute the upstream workflow while keeping provenance and source boundaries explicit in the working notes.

Imported Workflow Notes

Imported: 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' }),
});

Imported: 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

Examples

Example 1: Ask for the upstream workflow directly

Use @frontend-dev-guidelines-v2 to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.

Explanation: This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

Example 2: Ask for a provenance-grounded review

Review @frontend-dev-guidelines-v2 against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.

Explanation: Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

Example 3: Narrow the copied support files before execution

Use @frontend-dev-guidelines-v2 for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.

Explanation: This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

Example 4: Build a reviewer packet

Review @frontend-dev-guidelines-v2 using the copied upstream files plus provenance, then summarize any gaps before merge.

Explanation: This is useful when the PR is waiting for human review and you want a repeatable audit packet.

Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

• Keep the imported skill grounded in the upstream repository; do not invent steps that the source material cannot support.
• Prefer the smallest useful set of support files so the workflow stays auditable and fast to review.
• Keep provenance, source commit, and imported file paths visible in notes and PR descriptions.
• Point directly at the copied upstream files that justify the workflow instead of relying on generic review boilerplate.
• Treat generated examples as scaffolding; adapt them to the concrete task before execution.
• Route to a stronger native skill when architecture, debugging, design, or security concerns become dominant.

Troubleshooting

Problem: The operator skipped the imported context and answered too generically

Symptoms: The result ignores the upstream workflow in plugins/antigravity-awesome-skills/skills/frontend-dev-guidelines, fails to mention provenance, or does not use any copied source files at all. Solution: Re-open metadata.json, ORIGIN.md, and the most relevant copied upstream files. Check the external_source block first, then restate the provenance before continuing.

Problem: The imported workflow feels incomplete during review

Symptoms: Reviewers can see the generated SKILL.md, but they cannot quickly tell which references, examples, or scripts matter for the current task. Solution: Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it.

Problem: The task drifted into a different specialization

Symptoms: The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. Solution: Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.

Related Skills

• @cred-omega-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @customs-trade-compliance-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @docker-expert-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @ejentum-reasoning-harness-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.

Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

• common-patterns.md
• complete-examples.md
• component-patterns.md
• data-fetching.md
• file-organization.md
• loading-and-error-states.md

Imported Reference Notes

Imported: 1. Frontend Feasibility & Complexity Index (FFCI)

Before implementing a component, page, or feature, assess feasibility.

FFCI Dimensions (1–5)

Score Formula

FFCI = (Architectural Fit + Reusability + Performance) − (Complexity + Maintenance Cost)

Range: -5 → +15

Interpretation

Imported: 3. Quick Start Checklists

New Component Checklist

• React.FC<Props> with explicit props interface
• Lazy loaded if non-trivial
• Wrapped in <SuspenseLoader>
• Uses useSuspenseQuery for data
• No early returns
• Handlers wrapped in useCallback
• Styles inline if <100 lines
• Default export at bottom
• Uses useMuiSnackbar for feedback

New Feature Checklist

• Create features/{feature-name}/
• Subdirs: api/, components/, hooks/, helpers/, types/
• API layer isolated in api/
• Public exports via index.ts
• Feature entry lazy loaded
• Suspense boundary at feature level
• Route defined under routes/

Imported: 4. Import Aliases (Required)

Aliases must be used consistently. Relative imports beyond one level are discouraged.

Imported: 5. Component Standards

Required Structure Order

1. Types / Props
2. Hooks
3. Derived values (useMemo)
4. Handlers (useCallback)
5. Render
6. Default export

Lazy Loading Pattern

const HeavyComponent = React.lazy(() => import('./HeavyComponent'));

Always wrapped in <SuspenseLoader>.

Imported: 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

Imported: 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.

Imported: 9. Loading & Error Handling

Absolute Rule

❌ Never return early loaders ✅ Always rely on Suspense boundaries

User Feedback

• useMuiSnackbar only
• No third-party toast libraries

Imported: 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.

Imported: 11. TypeScript Standards

• Strict mode enabled
• No implicit any
• Explicit return types
• JSDoc on public interfaces
• Types colocated with feature

Imported: 12. Canonical File Structure

src/
  features/
    my-feature/
      api/
      components/
      hooks/
      helpers/
      types/
      index.ts

  components/
    SuspenseLoader/
    CustomAppBar/

  routes/
    my-route/
      index.tsx

Imported: 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;

Imported: 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

Imported: 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

Imported: 16. Operator Validation Checklist

Before finalizing code:

• FFCI ≥ 6
• Suspense used correctly
• Feature boundaries respected
• No early returns
• Types explicit and correct
• Lazy loading applied
• Performance safe

Imported: 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.

Imported: 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.