retro_requirements

Reverse-engineer codebases into structured requirements through a 9-phase process.

4|Updated Jun 22, 2026

Search Tags:#code analysis #codebase analysis #requirements engineering #systematic analysis #reverse engineering

Ready to run

npx skills add https://github.com/blendsdk/claude-codeops --skill retro-requirements

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: retro_requirements
Source: https://github.com/blendsdk/claude-codeops/tree/main/skills/retro_requirements
Command: npx skills add https://github.com/blendsdk/claude-codeops --skill retro-requirements

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires retro_requirements, and includes scripts (resource) and references (resource) and assets (resource) components.

What problem does it solve?

This Skill helps reconstruct requirements from existing, undocumented, or legacy codebases, providing a structured description that can be used for documentation, migration, or a from-scratch rebuild.

Core Features & Use Cases

Reverse Engineering: Analyzes any language/framework through a 9-phase archaeology pipeline.
Requirement Extraction: Extracts what the system does (not how) and classifies behaviors by confidence.
Use Case: Use this Skill to document what an existing application does, or to extract requirements for a migration or rebuild.

Quick Start

Run the retro_requirements skill with the --continue flag to resume an interrupted session.

Frequently Asked Questions about retro_requirements

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I reverse-engineer requirements from an existing legacy codebase?▼

You reverse-engineer requirements from a legacy codebase by applying a systematic 9-phase archaeology pipeline that identifies behaviors, extracts domain knowledge, and classifies confidence levels for documentation or migration planning.

What is the best way to extract system behaviors from undocumented source code?▼

The best way to extract system behaviors from undocumented source code is through systematic analysis that identifies what the system does rather than how it works, classifying extracted requirements by confidence levels for structured documentation.

Can I analyze codebases written in any programming language for migration planning?▼

Yes, you can analyze codebases written in any language or framework for migration planning because the reverse-engineering pipeline applies systematic analysis to extract domain knowledge regardless of the underlying technology stack.

Do I need Python installed to extract structured requirements from an application?▼

Yes, you need Python and various analysis libraries installed to extract structured requirements from an application, as the reverse-engineering pipeline relies on these dependencies to execute its systematic 9-phase codebase analysis.

How do I resume an interrupted codebase analysis session?▼

To resume an interrupted codebase analysis session, run the retro_requirements skill with the --continue flag, which restores the previous state of the systematic reverse-engineering pipeline.

When should I use reverse engineering instead of forward requirements engineering?▼

You should use reverse engineering instead of forward requirements engineering when you have an existing, undocumented, or legacy codebase that needs structured descriptions for documentation, migration, or a from-scratch rebuild.