Overview
doubt-driven-development is an open-source testing skill for Claude Code and compatible agents, published by addyosmani. Its author describes it as: “Subjects every non-trivial decision to a fresh-context adversarial review before it stands. Use when you want every assumption cross-examined before proceeding, when stress-testing a plan for hidden failure modes, whe…”. 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 doubt-driven-development does
A confident answer is not a correct one. Long sessions accumulate context that quietly turns assumptions into "facts" without anyone noticing. Doubt-driven development is the discipline of materializing a fresh-context reviewer — biased to **disprove**, not approve — before any non-trivial output stands.
Best for
What’s inside
The SKILL.md for doubt-driven-development is organised into these sections:
- Overview
- When to Use
- Loading Constraints
- The Process
- Step 1: CLAIM — Surface what stands
- Step 2: EXTRACT — Smallest reviewable unit
- Step 3: DOUBT — Invoke the fresh-context reviewer
- Step 4: RECONCILE — Fold findings back
- Step 5: STOP — Bounded loop, not recursion
- Common Rationalizations
- Red Flags
- Interaction with Other Skills
Installation
Add doubt-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
doubt-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 16,916 GitHub stars over the last 52 days
Author
Topics
Alternatives to doubt-driven-development
Similar skills from other repositories:
Frequently asked questions
- What does doubt-driven-development do?
- Subjects every non-trivial decision to a fresh-context adversarial review before it stands. Use when you want every assumption cross-examined before proceeding, when stress-testing a plan for hidden failure modes, when correctness matters more than speed, when working in unfamiliar code, when stakes are high (production auth, security-sensitive logic, a high-stakes migration, irreversible operations), or any time a confident output would be cheaper to verify now than to debug later.
- How do I install doubt-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 doubt-driven-development free to use?
- Yes. doubt-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 doubt-driven-development work with?
- doubt-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 doubt-driven-development come from?
- doubt-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.
