Legacy Bridge

Quick Navigation:
Level 1: [Quick Start](#level-1-quick-start) (5 min) → Level 2: [Implementation](#level-2-implementation) (30 min) → Level 3: [Mastery](#level-3-mastery-resources) (Extended)

Level 1: Quick Start

Overview

The legacy-bridge skill provides backward compatibility for existing @load patterns used in CLAUDE.md and the product-matrix system. This bridge enables a zero-breaking-change migration path from the legacy standards loader to the new Skills-based architecture.

Migration Timeline: 6-month transition period (deprecation warnings only, no breaking changes)

When to Use

Use this skill when:

• You have existing code using @load product:* patterns
• You need to maintain backward compatibility during migration
• You want to gradually transition to the new Skills format

Quick Reference

Level 2: Implementation

Pattern Translation

The legacy-bridge automatically translates old @load patterns to new skill loads:

Product Type Patterns

# Old Pattern → New Skill Loading
@load product:api         → Load: [coding-standards, testing, security, devops]
@load product:web-service → Load: [coding-standards, testing, security, frontend, devops]
@load product:frontend-web → Load: [frontend, testing, security]

Standard Code Patterns

# Coding Standards (CS)
@load CS:python       → Load: skills/coding-standards/python
@load CS:javascript   → Load: skills/coding-standards/javascript

# Testing Standards (TS)
@load TS:pytest       → Load: skills/testing/pytest
@load TS:*            → Load: skills/testing/* (all testing skills)

# Security Standards (SEC)
@load SEC:auth        → Load: skills/security/authentication
@load SEC:*           → Load: skills/security/* + NIST-IG:base

Composite Patterns

# Multiple standards combined
@load [product:api + CS:python + TS:pytest]
  → Load: product:api skills + python coding + pytest testing

Wildcard Expansion

The bridge automatically expands wildcards:

SEC:*  expands to:
  - SEC:auth
  - SEC:secrets
  - SEC:input-validation
  - NIST-IG:base  # Auto-included with security

TS:* expands to:
  - TS:unit
  - TS:integration
  - TS:e2e

Auto-Inclusion Rules

NIST Baseline Auto-Loading:

• Any security standard (SEC:*) automatically includes NIST-IG:base
• Explicit override available with --no-auto-nist flag

Level 3: Mastery Resources

Migration Guide

Phase 1: Compatibility Mode (Current)

Both patterns work side-by-side:

# Legacy pattern (still works)
@load product:api

# New skill pattern (recommended)
skill-loader.py load product:api

Phase 2: Deprecation Warnings (Month 3-6)

Deprecation warnings will appear in logs.

Phase 3: Legacy Removal (Month 6+)

Legacy syntax will be removed. Migration guide available.

Migration Tools

# Scan codebase for legacy patterns
skill-loader.py audit-legacy --path .

# Generate migration report
skill-loader.py migration-report --output migration-plan.md

# Auto-migrate files (with backup)
skill-loader.py migrate --path . --backup

Related Skills

• [skill-loader](../skill-loader/SKILL.md) - New skill loading mechanism
• [coding-standards](../coding-standards/SKILL.md) - Base coding standards
• [security-practices](../security-practices/SKILL.md) - Security implementations

External Resources

• resources/legacy-mappings.yaml - Complete mapping definitions
• config/product-matrix.yaml - Original product definitions
• examples/legacy-patterns/ - Migration examples