deprecation-and-migration

deprecation-and-migration is an open-source backend skill for Claude Code and compatible agents, published by addyosmani. Its author describes it as: “Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one implementation to another. Use when deciding whether to maintain or sunset existing code.”. The project has 88k stars on GitHub and is available under the MIT license. Add it to your setup with `/plugin marketplace add addyosmani/agent-skills`.

What deprecation-and-migration does

Code is a liability, not an asset. Every line of code has ongoing maintenance cost — bugs to fix, dependencies to update, security patches to apply, and new engineers to onboard. Deprecation is the discipline of removing code that no longer earns its keep, and migration is the process of moving users safely from the old to the new.

Installation

Add deprecation-and-migration to your agent with:

/plugin marketplace add addyosmani/agent-skills

Always review a skill's source before installing it. This command comes from the skill's public repository; the linked repo is the source of truth for exact setup steps.

What's inside

The SKILL.md for deprecation-and-migration is organised into these sections:

• Overview
• When to Use
• Core Principles
• Code Is a Liability
• Hyrum's Law Makes Removal Hard
• Deprecation Planning Starts at Design Time
• The Deprecation Decision
• Compulsory vs Advisory Deprecation
• The Migration Process
• Step 1: Build the Replacement
• Step 2: Announce and Document
• Step 3: Migrate Incrementally

When to use it

Reach for deprecation-and-migration when you want backend help from your agent without writing the same instructions every session. Load the skill and the agent picks it up automatically for relevant tasks.

Strengths

• Clear MIT license — safe to read and adapt
• Ships in addyosmani/agent-skills, an established project with 88,280 GitHub stars
• Actively maintained (recent commits)

Topics

Frequently asked questions

What does deprecation-and-migration do?

Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one implementation to another. Use when deciding whether to maintain or sunset existing code.

How do I install deprecation-and-migration?

Run /plugin marketplace add addyosmani/agent-skills in your agent, then reload your skills. Review the source at https://github.com/addyosmani/agent-skills before installing.

Is deprecation-and-migration free to use?

Yes. deprecation-and-migration is free and open source under the MIT license, so you can read, run, and adapt it within that license's terms.

Where does deprecation-and-migration come from?

deprecation-and-migration ships inside addyosmani/agent-skills, a repository that contains 25 catalogued skills in total. The repository's 88,280 GitHub stars apply to that whole collection, not to this skill on its own.