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archaeologist

Guide legacy code modification with characterization tests and feature flags.

Updated Feb 23, 2026
Search Tags:#debugging#documentation#safety#code#legacy#characterization-tests
One-click install
npx skills add https://github.com/mcevoyinit/agentic-skills --skill archaeologist
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: archaeologist
Source: https://github.com/mcevoyinit/agentic-skills/tree/main/skills/coding-modes/archaeologist
Command: npx skills add https://github.com/mcevoyinit/agentic-skills --skill archaeologist

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Legacy code mode for safely modifying code you don't fully understand. Understand before touching. Characterization tests first. Never delete "dead" code without confirmation. Minimal blast radius with feature flags. Document what you learn. Prevents confident destruction of load-bearing code you misidentified as dead.

Core Features & Use Cases

  • Guided, risk-aware workflow for exploring unfamiliar or legacy codebases.
  • Characterization tests first to capture current behavior before changes.
  • Minimal, reversible edits behind feature flags with clear documentation of learnings.
  • Repeatable archaeology protocol: read, test, modify, validate, and document changes.

Quick Start

Activate Archaeologist mode and begin a guided, test-first modification session before touching any code.

Frequently Asked Questions about archaeologist

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

FAQPage Schema
How do I reduce the blast radius of changes in a complex codebase?▼

To reduce the blast radius of changes in a complex codebase, make minimal, reversible edits gated by feature flags. This ensures safe rollout and allows you to validate changes against characterization tests before full deployment.

How do I safely modify legacy code I don't fully understand?▼

To safely modify legacy code, you must understand it before touching anything, write characterization tests to capture current behavior, make minimal reversible changes behind feature flags, and document what you learn to ensure safe rollout.

What are characterization tests and when do I need them for legacy code?▼

Characterization tests capture the current behavior of legacy code before changes. You need them when working with complex or poorly understood codebases to prevent confidently destroying load-bearing code you misidentified as dead.

How do I safely edit unfamiliar codebases without breaking existing functionality?▼

Safely editing unfamiliar codebases requires a repeatable archaeology protocol: read code and git history, create characterization tests, make minimal edits behind feature flags, and validate and document changes for safe rollout.

Can I delete dead code in a legacy codebase without running tests first?▼

Never delete dead code in a legacy codebase without confirmation. Code that appears dead may be load-bearing, so you must write characterization tests first to capture behavior and prevent confident destruction of critical functionality.

How do I reduce the blast radius of changes in a complex codebase?▼

To reduce the blast radius of changes in a complex codebase, make minimal, reversible edits gated by feature flags. This ensures safe rollout and allows you to validate changes against characterization tests before full deployment.

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