Overview
constraint-driven-development is an open-source testing skill for Claude Code and compatible agents, published by addyosmani. Its author describes it as: “Establishes a project's quality bar as a written contract and stops agents quietly lowering it. Interviews the user on which dimensions matter, supplies sane default thresholds when they have no number in mind, record…”. The project has 98k stars on GitHub and is available under the MIT license. Add it to your setup with `/plugin marketplace add addyosmani/agent-skills`.
What constraint-driven-development does
Other skills in this pack describe what good looks like. `code-review-and-quality` gives you five axes. `test-driven-development` gives you a cycle. `security-and-hardening` gives you a threat list. All of that lives in prose the agent reads and may or may not follow, and none of it survives the end of the session.
What’s inside
The SKILL.md for constraint-driven-development is organised into these sections:
- Overview
- When to Use
- Loading Constraints
- The Process
- Step 1: Detect before you ask
- Step 2: Four questions, each with a default
- Step 3: Write CONSTRAINTS.md
- Step 4: Install what each dimension needs
- Step 5: Wire it to the lifecycle
- Step 6: Guard the bar itself
- Step 7: Ratchets, when you don't have a number
- Sane Defaults
Installation
Add constraint-driven-development to your agent with:
/plugin marketplace add addyosmani/agent-skillsReview a skill’s source before installing it — skills can instruct your agent to run commands. This command comes from the skill’s public repository, which is the source of truth for setup steps. New to skills? Read how to install Claude Code skills.
Supported agents
- Claude Code — ships a claude code plugin marketplace
- Codex — declared in the repository topics
- Cursor — declared in the repository topics
- Antigravity — declared in the repository topics
License
constraint-driven-development is published under the MIT license.
Strengths
- Clear MIT license — safe to read and adapt within its terms
- Ships in addyosmani/agent-skills, an established project with 97,992 GitHub stars
- Works with Claude Code, Codex, Cursor, Antigravity
- Actively maintained — repository updated in the last 30 days
- Its repository gained 6,925 GitHub stars over the last 21 days
Author
Topics
Frequently asked questions
- What does constraint-driven-development do?
- Establishes a project's quality bar as a written contract and stops agents quietly lowering it. Interviews the user on which dimensions matter, supplies sane default thresholds when they have no number in mind, records everything in CONSTRAINTS.md, and watches the diff for a weakened bar — new @ts-ignore or eslint-disable suppressions, skipped or deleted tests, assertions stripped out, unimplemented stubs, thresholds edited down. Use when no quality bar is written down, when the user says "set up constraints" or "define our standards", when the user wants dimensions they care about — accessibility, web performance, coverage — set up as enforced constraints, when an agent keeps silencing checks or skipping tests to get to green, when you need a coverage or performance threshold and don't know what number to pick, or when an agent writes more code than anyone will read.
- How do I install constraint-driven-development?
- Run /plugin marketplace add addyosmani/agent-skills in your agent, then reload your skills. Review the source at https://github.com/addyosmani/agent-skills before installing.
- Is constraint-driven-development free to use?
- Yes. constraint-driven-development is free and open source under the MIT license, so you can read, run, and adapt it within that license's terms.
- Which agents does constraint-driven-development work with?
- constraint-driven-development lists Claude Code, Codex, Cursor, and Antigravity — named in its SKILL.md, its plugin marketplace or its repository topics. Skills use the portable SKILL.md format, so other agents that read that format may load it too.
- Where does constraint-driven-development come from?
- constraint-driven-development ships inside addyosmani/agent-skills, a repository that contains 26 catalogued skills in total. The repository's 97,992 GitHub stars apply to that whole collection, not to this skill on its own.
