working-effectively-with-legacy-code
Apply Michael Feathers-inspired legacy-code rules when changing hard-to-test code safely with characterization tests, seams, sprout methods, or wrap methods.
Install / Use
npx skills add ciembor/agent-rules-books --skill working-effectively-with-legacy-codeInstalls into whichever agent you are using.
SKILL.md
Installable skill definition
Quality Score
Category
Development & EngineeringSupported Platforms
Our assessment of working-effectively-with-legacy-code
working-effectively-with-legacy-code scores 86/100 on our quality scale, 1124th of 3,168 Development & Engineering skills we index (top 36%).
We have not analysed the SKILL.md file itself yet, so the content part of this score is an estimate until our crawler reaches it.
With 2,876 GitHub stars, it is one of the more widely adopted skills in the catalogue.
Maintenance, license and trust
- The repository was last updated 18 days ago, so working-effectively-with-legacy-code is actively maintained.
- It is released under the MIT license, a permissive license that allows use, modification and commercial use with attribution.
- Its trust signals score 100/100, with no cautions. These come from repository metadata, not a code audit — read the skill file before letting an agent act on it.
working-effectively-with-legacy-code compared with similar skills
All 4 of these similar skills score higher than working-effectively-with-legacy-code; compare them before choosing.
| Skill | Score | Stars | Updated | Format |
|---|---|---|---|---|
| working-effectively-with-legacy-code (this skill)by ciembor | 86 | 2.9k | 18d ago | SKILL.md |
| ai-job-searchby MadsLorentzen | 100 | 44.4k | today | CLAUDE.md |
| claude-howtoby luongnv89 | 100 | 41.7k | 2d ago | CLAUDE.md |
| algorithmic-artby anthropics | 100 | 177.9k | 6d ago | SKILL.md |
| pptxby anthropics | 100 | 177.9k | 6d ago | SKILL.md |
Frequently asked questions
- How do I install working-effectively-with-legacy-code?
- Run
npx skills add ciembor/agent-rules-books --skill working-effectively-with-legacy-code. The install tabs above show the steps for each supported agent. - Which AI agents does working-effectively-with-legacy-code work with?
- It is written for Universal, as a SKILL.md file. Other agents that read the same format can often use it too.
- Is working-effectively-with-legacy-code safe to use?
- It is MIT-licensed and scores 100/100 on trust signals. Skills are instructions an agent will follow, so read the file before installing it and do not approve commands you do not understand.
- Is working-effectively-with-legacy-code still maintained?
- The repository was last updated 18 days ago, so working-effectively-with-legacy-code is actively maintained.
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Trust signals
From repository metadata: license, adoption, age and documentation. Not a code audit — see the Safety scan above for what the skill file itself contains.