Pattern Discovery Skill

Purpose

Enforce pattern-first development by checking the Pattern library before implementing new functionality. This reduces code duplication, ensures consistency, and leverages battle-tested solutions.

When to Use

Invoke this skill when:

• About to create a new API route
• About to create a new UI component
• About to add database operations
• About to write integration tests
• User asks "how do I implement..." or "how should I build..."
• Starting work on any feature implementation

Pattern Discovery Protocol

ALWAYS follow this sequence before writing new code:

Step 1: Check Pattern Library

Search docs/patterns/ for existing patterns:

# Find patterns by category
ls docs/patterns/api/      # API route patterns
ls docs/patterns/ui/       # UI component patterns
ls docs/patterns/database/ # Database operation patterns
ls docs/patterns/testing/  # Testing patterns

Step 2: Review Pattern Index

Check docs/patterns/README.md for the complete pattern index:

| Category | Patterns Available | | -------- | --------------------------------------------------------------------------- | | API | User Context, Admin Context, Webhook Handler, Zod Validation, Bonus Content | | UI | Authenticated Page, Form with Validation, Data Table, Marketing Page | | Database | RLS Migration, Prisma Transaction, Server Component Access | | Testing | API Integration Test, E2E User Flow |

Step 3: Apply or Escalate

If pattern exists:

1. Read the pattern file
2. Copy the code pattern
3. Follow the customization guide
4. Run validation commands

If pattern is missing:

1. Search codebase for similar implementations
2. If found, consider extracting as new pattern (BSA/ARCHitect only)
3. If not found, implement from scratch following existing conventions
4. Report pattern gap to BSA for future extraction

Pattern Library Structure

docs/patterns/
├── README.md           # Pattern index and usage guide
├── api/
│   ├── user-context-api.md
│   ├── admin-context-api.md
│   ├── webhook-handler.md
│   ├── zod-validation-api.md
│   └── bonus-content-delivery.md
├── ui/
│   ├── authenticated-page.md
│   ├── form-with-validation.md
│   ├── data-table.md
│   └── marketing-page.md
├── database/
│   ├── rls-migration.md
│   ├── prisma-transaction.md
│   └── server-component-direct-access.md
├── testing/
│   ├── api-integration-test.md
│   └── e2e-user-flow.md
└── ci/
    ├── service-configuration-pattern.md
    └── database-setup-pattern.md

Pattern Matching Guide

| If you need to... | Use this pattern | | ---------------------------------- | --------------------------------- | | Create authenticated API endpoint | api/user-context-api.md | | Create admin-only API endpoint | api/admin-context-api.md | | Handle external webhooks | api/webhook-handler.md | | Validate API input with Zod | api/zod-validation-api.md | | Serve private downloadable content | api/bonus-content-delivery.md | | Create protected page | ui/authenticated-page.md | | Build form with validation | ui/form-with-validation.md | | Display paginated data | ui/data-table.md | | Create marketing/landing page | ui/marketing-page.md | | Add new table with RLS | database/rls-migration.md | | Run multi-step DB operations | database/prisma-transaction.md | | Test API endpoints | testing/api-integration-test.md | | Write E2E user flow tests | testing/e2e-user-flow.md |

Security Requirements

All patterns enforce:

• RLS Context - Database operations use withUserContext, withAdminContext, or withSystemContext
• Authentication - Protected routes verify auth before processing
• Input Validation - All inputs validated with Zod schemas
• Error Handling - Comprehensive error handling with proper status codes

Validation Commands

After applying a pattern, run:

yarn lint && yarn type-check  # All patterns
yarn test:integration         # API patterns
yarn test:e2e                 # UI patterns

Authoritative Reference

• Pattern Index: docs/patterns/README.md
• RLS Patterns: See rls-patterns skill for database security
• Frontend Patterns: See frontend-patterns skill for UI conventions