# Doubt Driven Development (agent skill)

> Doubt Driven Development is an agent skill (a SKILL.md file) from addyosmani/agent-skills. Subjects every non-trivial decision to a fresh-context adversarial review before it stands. It works with Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot and OpenCode and has 102,166 GitHub stars across a repository of 13 listed skills.

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.

## Key facts

| Fact | Value |
|---|---|
| Repository | https://github.com/addyosmani/agent-skills |
| Skill path | skills/doubt-driven-development/SKILL.md |
| Skill name | doubt-driven-development |
| GitHub stars | 102,166 |
| Installs on skills.sh | 823 |
| License | MIT |
| Skills in repo | 13 |
| Plugin marketplace | addy-agent-skills |
| Official | no |
| Works with | Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, OpenCode |
| Category | Security |
| Last commit | Oct 3, 2026 |

## When it triggers

- 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, secu

## Add this skill

### Claude Code

```sh
/plugin marketplace add addyosmani/agent-skills
/plugin install agent-skills@addy-agent-skills
```

In the Claude apps, zip the skill folder and upload it under Customize > Skills > + > Upload a skill (code execution must be on).

### ChatGPT / Codex

```sh
git clone --depth 1 https://github.com/addyosmani/agent-skills.git
cp -r agent-skills/skills/doubt-driven-development .agents/skills/doubt-driven-development   # repo; ~/.agents/skills for all projects
```

### Cursor

```sh
git clone --depth 1 https://github.com/addyosmani/agent-skills.git
cp -r agent-skills/skills/doubt-driven-development .cursor/skills/doubt-driven-development   # project; ~/.cursor/skills for all projects
```

Sources (checked 2026-10-07): https://code.claude.com/docs/en/skills, https://support.claude.com/en/articles/12512180-using-skills-in-claude, https://learn.chatgpt.com/docs/build-skills, https://cursor.com/docs/context/skills

skills.sh listing: https://www.skills.sh/addyosmani/agent-skills/doubt-driven-development

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Canonical page: https://appsgit.com/skills/addyosmani-doubt-driven-development
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