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 patterns_library/ for existing patterns:

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

Step 2: Review Pattern Index

Check patterns_library/README.md for the complete pattern index:

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

patterns_library/
├── 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
├── security/
│   ├── input-sanitization.md
│   ├── rate-limiting.md
│   └── secrets-management.md
├── ci/
│   ├── github-actions-workflow.md
│   └── deployment-pipeline.md
└── config/
    ├── environment-config.md
    └── structured-logging.md

Pattern Matching Guide

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