deprecation-and-migration is agent-read markdown (skill) from nota-america/forgecat-agent-profiles: Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one implementation to another. Use when migrating a database schema in production, such as renaming or dropping a column without downtime (expand/contract). Use when deciding whether to maintain or sunset existing code..
Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.
What the file says
# Deprecation and Migration
## Overview
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.
Most engineering organizations are good at building things. Few are good at removing them. This skill addresses that gap.
## When to Use
- Replacing an old system, API, or library with a new one
- Sunsetting a feature that's no longer needed
- Consolidating duplicate implementations
- Removing dead code that nobody owns but everybody depends on
- Planning the lifecycle of a new system (deprecation planning starts at design time)
- Deciding whether to maintain a legacy system or invest in migration
## Core Principles
### Code Is a Liability
…
Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.
GET https://markdownregistry.com/api/v1/artifacts/art_kufk73hjx7wtvexl
GET https://markdownregistry.com/api/v1/resolve?ref=nota-america/forgecat-agent-profiles/deprecation-and-migration
GET https://markdownregistry.com/api/v1/blob/6a624f942e09c69863a4219b9bd5d56975026b67b0c70bc83385ffd2120b6142
Your agent does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/api-and-interface-design/SKILL.md · Guides stable API and interface design. Use when designing APIs,
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/browser-testing-with-devtools/SKILL.md · Tests in real browsers via Chrome DevTools MCP. Use when building
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/ci-cd-and-automation/SKILL.md · Automates CI/CD pipeline setup. Use when setting up or modifying
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/code-review-and-quality/SKILL.md · Conducts multi-axis code review. Use before merging any change. Use
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/code-simplification/SKILL.md · Simplifies code for clarity. Use when refactoring code for clarity
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/constraint-driven-development/SKILL.md · Establishes a project's quality bar as a written contract and stops
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/context-engineering/SKILL.md · Optimizes agent context setup. Use when starting a new session,
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems,
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/documentation-and-adrs/SKILL.md · Records decisions and documentation. Use when you need to document
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/doubt-driven-development/SKILL.md · Subjects every non-trivial decision to a fresh-context adversarial
addyosmani/agent-skills · skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
shashankswe2020-ux/whoop-mcp · .github/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-claude/.claude/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems,
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-codex/.agents/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-forgecat/platforms/codex/.agents/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-forgecat/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
nota-america/forgecat-agent-profiles · profiles/addyosmani/agent-skills/for-cursor/.cursor/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
hamza-ali-shahjahan/hamzaish · factory/skills/deprecation-and-migration/SKILL.md · Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one…
