Community · by addyosmani

Spec-driven development Claude skill

The Spec-driven development skill guides an AI assistant to draft a structured specification before coding begins, giving the team a common reference point.

MIT licence
★ 108,503 on GitHub (whole repository)
Verified against its source 19 Oct 2026

View SKILL.md Repository

What the Spec-driven development skill does

The assistant drafts a structured spec ahead of writing code, states its assumptions at the outset, and converts ambiguous requirements into measurable success criteria. It suits launching a fresh project, a new feature, or a major change when no spec is in place yet.

What it covers

Clarifying requirements and surfacing assumptions before writing a spec
Reframing vague requirements into testable success criteria

How to install it

In Claude Code

/plugin marketplace add addyosmani/agent-skills

/plugin install agent-skills@addy-agent-skills

This plugin also installs: api-and-interface-design, browser-testing-with-devtools, ci-cd-and-automation, code-review-and-quality, code-simplification, constraint-driven-development, context-engineering, debugging-and-error-recovery, deprecation-and-migration, documentation-and-adrs, doubt-driven-development, frontend-ui-engineering, git-workflow-and-versioning, idea-refine, incremental-implementation, interview-me, observability-and-instrumentation, performance-optimization, planning-and-task-breakdown, security-and-hardening, shipping-and-launch, source-driven-development, test-driven-development, using-agent-skills.

In Codex

codex plugin add agent-skills@agent-skills

What you need

In its documentation's own words:

“Install as a native Codex plugin (Codex CLI v0.122+)”

Steps change between versions. Check the official instructions before you install.