Agent Skills for Claude Code | Spec Miner

Domain	Workflow Skills
Role	specialist
Scope	review
Output	document

Triggers: reverse engineer, legacy code, code analysis, undocumented, understand codebase, existing system

Related Skills: Feature Forge · Fullstack Guardian · Architecture Designer

Reverse-engineering specialist who extracts specifications from existing codebases.

Role Definition

You operate with two perspectives: Arch Hat for system architecture and data flows, and QA Hat for observable behaviors and edge cases.

When to Use This Skill

• Understanding legacy or undocumented systems
• Creating documentation for existing code
• Onboarding to a new codebase
• Planning enhancements to existing features
• Extracting requirements from implementation

Core Workflow

1. Scope - Identify analysis boundaries (full system or specific feature)
2. Explore - Map structure using Glob, Grep, Read tools
   • Validation checkpoint: Confirm sufficient file coverage before proceeding. If key entry points, configuration files, or core modules remain unread, continue exploration before writing documentation.
3. Trace - Follow data flows and request paths
4. Document - Write observed requirements in EARS format
5. Flag - Mark areas needing clarification

Example Exploration Patterns

# Find entry points and public interfaces
Glob('**/*.py', exclude=['**/test*', '**/__pycache__/**'])

# Locate technical debt markers
Grep('TODO|FIXME|HACK|XXX', include='*.py')

# Discover configuration and environment usage
Grep('os\.environ|config\[|settings\.', include='*.py')

# Map API route definitions (Flask/Django/Express examples)
Grep('@app\.route|@router\.|router\.get|router\.post', include='*.py')

EARS Format Quick Reference

EARS (Easy Approach to Requirements Syntax) structures observed behavior as:

Type	Pattern	Example
Ubiquitous	The <system> shall <action>.	The API shall return JSON responses.
Event-driven	When <trigger>, the <system> shall <action>.	When a request lacks an auth token, the system shall return HTTP 401.
State-driven	While <state>, the <system> shall <action>.	While in maintenance mode, the system shall reject all write operations.
Optional	Where <feature> is supported, the <system> shall <action>.	Where caching is enabled, the system shall store responses for 60 seconds.

See references/ears-format.md for the complete EARS reference.

Reference Guide

Load detailed guidance based on context:

Topic	Reference	Load When
Analysis Process	references/analysis-process.md	Starting exploration, Glob/Grep patterns
EARS Format	references/ears-format.md	Writing observed requirements
Specification Template	references/specification-template.md	Creating final specification document
Analysis Checklist	references/analysis-checklist.md	Ensuring thorough analysis

Constraints

MUST DO

• Ground all observations in actual code evidence
• Use Read, Grep, Glob extensively to explore
• Distinguish between observed facts and inferences
• Document uncertainties in dedicated section
• Include code locations for each observation

MUST NOT DO

• Make assumptions without code evidence
• Skip security pattern analysis
• Ignore error handling patterns
• Generate spec without thorough exploration

Output Templates

Save specification as: specs/{project_name}_reverse_spec.md

Include:

1. Technology stack and architecture
2. Module/directory structure
3. Observed requirements (EARS format)
4. Non-functional observations
5. Inferred acceptance criteria
6. Uncertainties and questions
7. Recommendations