Agent Skills is Addy Osmani's set of 25 skills that gives coding agents step-by-step workflows for every project stage.
You do not need to read 25 files, because each stage uses only a few skills.What is Agent Skills for?
Agent Skills · by Addy Osmani
Gives your agent step-by-step workflows for every stage of a project, from defining the idea to deploying it.
Each stage has its own command, and matching skills also activate based on what you are doing.
25
skills
9
slash commands
4
review personas
7
reference checklists
Start with /spec, /plan, /build, /test, /review, /ship
How does Agent Skills work?
Take a guess first
Who moves the project to the next stage?
You move between stages with each stage's command. The right skills then activate from the work at hand.
Pick a stage to see the skills inside
Explored 1/6
Clarify what to build
The agent writes a spec before it writes code.
interview-meAsks one question at a time until your request is clearidea-refineTurns a vague idea into a concrete proposalspec-driven-developmentWrites a PRD before any codeconstraint-driven-developmentWrites your quality thresholds to CONSTRAINTS.md
Break the work down
This skill splits a spec into small, verifiable tasks in dependency order.
planning-and-task-breakdownSplits a spec into tasks with acceptance criteria
Write code one thin slice at a time
/build auto runs the whole plan after one approval, still testing and committing each task.
incremental-implementationImplements, tests, verifies and commits one vertical slice at a timetest-driven-developmentRuns the red, green, refactor loopcontext-engineeringFeeds the agent the right information at the right timesource-driven-developmentChecks official docs before framework decisionsdoubt-driven-developmentUses a fresh context to challenge each decisionfrontend-ui-engineeringCovers components, design systems and WCAG 2.1 AAapi-and-interface-designDefines the API contract before the implementation
Prove it works
The agent needs passing tests before it can call the work done.
browser-testing-with-devtoolsReads the live DOM, console and network through Chrome DevTools MCPdebugging-and-error-recoveryReproduces the bug, localizes it, reduces it, fixes it and guards against a repeat
Quality gates before merge
The review skill scores code on five axes and keeps each change near 100 lines.
code-review-and-qualityReviews on five axes and labels severitycode-simplificationReduces complexity without changing behaviorsecurity-and-hardeningChecks OWASP Top 10, auth, secrets and dependenciesperformance-optimizationMeasures before optimizing
Deploy to production
/ship runs the review personas in parallel and merges them into a go or no-go.
git-workflow-and-versioningUses trunk-based development and atomic commitsci-cd-and-automationBuilds pipelines with quality gatesdeprecation-and-migrationRetires old systems and dead codedocumentation-and-adrsRecords the why behind decisionsobservability-and-instrumentationAdds structured logs, RED metrics and tracingshipping-and-launchRuns checklists, staged rollouts and rollback
The 25th skill, using-agent-skills, belongs to no stage. It picks the right skill for your current task.
How is Agent Skills different from other skill sets?
vs SuperpowersSuperpowers concentrates on the build loop. Agent Skills also covers security, CI/CD, observability and launch.vs pstackpstack lets one command choose the process. In Agent Skills you walk each stage with its own command.vs mattpocock/skillsMatt's set is strongest at requirements and has few skills after Build. Agent Skills has skills through launch.
When should you use Agent Skills?
Use it when
You want one process from idea to production
You want a human checkpoint at each stage
Your team uses several different AI tools
Skip it when
You only need a quick small fix
You want to hand off work and let it run for hours
How do you start with Agent Skills?
bash
npx skills add addyosmani/agent-skillsChoose if you want one set with steps all the way through deployment. Install the set and begin with /spec.