agent-skills: engineering lifecycle skills for coding agents (Addy Osmani)

Summary

agent-skills is an MIT-licensed pack of 25 SKILL.md workflows that walk a coding agent through the software lifecycle: define, plan, build, verify, review, and ship. Each skill has steps, checkpoints, and verification gates, and the pack adds nine slash commands and four agent personas. It had about 772 commits and 111,500 stars when read on 2026-10-29 (the date above is that reading date, not a release date).

Key points

• Install in Claude Code: /plugin marketplace add addyosmani/agent-skills, then /plugin install agent-skills@addy-agent-skills.
• Install in Codex (0.122+): codex plugin marketplace add addyosmani/agent-skills, then codex plugin add agent-skills@agent-skills.
• Other agents: npx skills add addyosmani/agent-skills (add --list to browse first). Per-skill npx installs leave out the shared references/ folder (issue #361), so install the whole pack.
• Good for: giving an agent a disciplined process. Examples: interview-me and spec-driven-development before coding, test-driven-development and incremental-implementation while building, browser-testing-with-devtools and code-review-and-quality before merging, and /spec, /plan, /build, /test, /review, and /ship as shortcuts.
• Its star count rose by about 2,100 in the week to 2026-10-29; the long commit history and per-agent setup guides suggest active maintenance.

Why it matters

Most skill packs cover one task; this one encodes a whole engineering process in a portable format that installs the same way in Claude Code, Codex, and other agents.