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/constraints)<a href="https://agentmods.dev/commands/addyosmani/agent-skills/constraints"><img src="https://agentmods.dev/badge/commands/addyosmani/agent-skills/constraints/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/constraints"><img src="https://agentmods.dev/badge/commands/addyosmani/agent-skills/constraints.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 | $0.00017 | $0.00598 |
| Opus 5.5 | $0.00007 | $0.00239 |
| Sonnet 5.5 | $0.00003 | $0.00120 |
| Haiku 4.5 | $0.00002 | $0.00060 |
Grade A, and why
constraints 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- constraints — 97% identical, 5 lines differ
What it actually says
Invoke the agent-skills:constraint-driven-development skill.
$ARGUMENTS
Default behaviour with no arguments: set up constraints for this repository.
-
Detect first. Read package.json / pyproject.toml / go.mod, the test runner, existing lint configs, current coverage output, CI workflows, and the agent harness in use. Report what you found in two lines. Never ask for anything you can read.
-
Interview, at most four questions. One at a time, each with your best guess and a usable default so "I don't know" still produces a working config:
- Which dimensions beyond the floor (coverage, security, performance, accessibility, architecture)
- Block or warn when a check fails mid-task
- Target numbers, or measure today's values and hold them
- Slowest check tolerated before handing work back
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Write CONSTRAINTS.md at the repo root with a Floor section, enforced numbers, measured-only metrics with today's values, and an exceptions table with owners and expiry dates. Every number needs a stated reason.
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Install what each picked dimension needs. A dimension with a number and no tool behind it is an aspiration. Use the de facto tool so existing config keeps working: Semgrep for code scanning, gitleaks (always
--redact) for secrets, osv-scanner for dependencies, axe-core for accessibility, Lighthouse for web vitals, size-limit for bundles, dependency-cruiser for boundaries, Stryker for assertion quality. Record the exact command next to each rule in CONSTRAINTS.md. Accessibility and performance need a running URL; if the project has none, say so and drop the dimension rather than inventing a check. Add the commands to package.json as check:fast / check:task / check:full. -
Place each check by cost. Types, lint and secrets in the edit loop (seconds). Related tests and changed-line coverage at task end (under 90s). Everything else at review or in CI. Scope checks to the diff, not the whole repo.
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Point the agent at it. Add a line to CLAUDE.md telling agents to read CONSTRAINTS.md and never weaken it to make a change pass.
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Verify. Run the constraints against the current branch. If anything fails that the user disagrees with, fix the constraint now rather than leaving a gate people will learn to ignore.
Sub-commands:
/constraints check— run the current constraints against this branch and report/constraints guard— inspect the diff for a weakened bar: lowered thresholds, skipped or deleted tests, new suppression comments, unfinished stubs, new exceptions/constraints ratchet— record today's measured values as the floor that must not fall
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 · 33 lines · 17 tokens per session scan A f6d8fdf69be7
constraints is a command published in the GitHub repository addyosmani/agent-skills (110,212 stars, last pushed 11d ago), licensed MIT. It adds 17 tokens to every session and 598 once invoked, about $0.0001 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.
review
A command that reviews code changes across correctness, readability, architecture, security, and performance.
spec
A command for specification-driven development, where the work is described and agreed in a structured document before coding begins.