addyosmani/agent-skills is a collection of reusable workflows, quality checks, commands, and other instructions that guide AI coding agents through software development. It is for developers who want agents to follow consistent engineering practices, and the catalogue entries are its packaged skills, commands, agents, plugins, instructions, and hooks.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/addyosmani/agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/commands/addyosmani/agent-skills/spec)<a href="https://agentmods.dev/commands/addyosmani/agent-skills/spec"><img src="https://agentmods.dev/badge/commands/addyosmani/agent-skills/spec/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/commands/addyosmani/agent-skills/spec"><img src="https://agentmods.dev/badge/commands/addyosmani/agent-skills/spec.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00012 | $0.00176 |
| Opus 5.5 | $0.00005 | $0.00070 |
| Sonnet 5.5 | $0.00002 | $0.00035 |
| Haiku 4.5 | $0.00001 | $0.00018 |
Grade A, and why
spec scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Invoke the agent-skills:spec-driven-development skill.
Begin by understanding what the user wants to build. Ask clarifying questions about:
- The objective and target users
- Core features and acceptance criteria
- Tech stack preferences and constraints
- Known boundaries (what to always do, ask first about, and never do)
Then generate a structured spec covering all six core areas: objective, commands, project structure, code style, testing strategy, and boundaries.
If the request bundles several independently testable capabilities, first propose a capability map (module ids, dependency direction, build order) per the skill's Phase 0 and get it approved, then spec each module in dependency order.
Save the spec as SPEC.md in the project root and confirm with the user before proceeding.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 18 lines · 12 tokens per session scan A 82325b4cc75a
spec is a command published in the GitHub repository addyosmani/agent-skills (107,397 stars, last pushed 3d ago), licensed MIT. It adds 12 tokens to every session and 176 once invoked, about $0.0000 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other commands, from other repositories
ship
A command that runs several specialist checks before software is released, then combines their findings into a decision about whether to launch.
build
A command for carrying out the next unfinished coding task from a plan, including writing tests, implementing the change, checking the project, and committing it. TDD, or test-driven development, means writing a failing test before the code that makes it pass.
constraints
A command for defining a project's quality standards through a short interview and a written CONSTRAINTS.md file. It records checks, thresholds, exceptions, and commands for enforcing them.
code-simplify
A code-review command that simplifies recently changed code or another chosen scope while preserving its behavior.
plan
A planning command that breaks software work into small, verifiable tasks with dependencies and acceptance criteria. Acceptance criteria describe what must be true for a task to be complete.
review
A command that reviews code changes across correctness, readability, architecture, security, and performance.