How do I install the API Deprecation Sunsetting skill?

Run npx skillmds@latest add deangrant/api-deprecation-sunsetting in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is API Deprecation Sunsetting safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with API Deprecation Sunsetting?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is API Deprecation Sunsetting free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published API Deprecation Sunsetting?

deangrant (@deangrant) published this skill. Their other Agent Skills are listed on their SkillMD profile.

API Deprecation Sunsetting by deangrant

Name: API Deprecation Sunsetting
Author: deangrant

API Deprecation Sunsetting

Deprecate and sunset API versions or fields using Deprecation, Sunset, and Link headers, plus 410 Gone. Use when retiring endpoints, publishing migration timelines, or reviewing compatibility windows.

deangrant 60b3d08 4 files · 2.4 KB Updated Sep 17, 2026

File contents

API Deprecation and Sunsetting

Use this skill when retiring versions, fields, or endpoints without surprising clients.

1. Signal early on success responses

On still-working (200) responses for deprecated resources:

Deprecation: (RFC 9745) — when deprecation took effect
Sunset: (RFC 8594) — when it will be removed
Link: …; rel="sunset" / rel="deprecation" — migration docs

2. After removal

Return 410 Gone (not 404) with problem+json and migration guidance.

3. Timeline

Publish announce → support → remind → monitor → remove. Example windows: 6mo announce / 12mo support / 18–24mo removal (adjust for audience; public APIs often need ≥24mo).

Track adoption metrics against migration expectations. Clients should pin versions explicitly.

4. Quick checklist

Deprecation + Sunset (+ Link) on deprecated-but-live responses.
Published timeline and migration docs.
410 at cutoff with problem+json.
Metrics for remaining traffic.
Clients instructed to pin versions.

See reference.md and examples.md.

Frequently asked questions