Status:✅ ACCEPTED

Date:📅 2026-04-25

Decision Makers:Joe Stump

ADR-0022: Rename Plugin to sdd (Spec-Driven Development)

Context and Problem Statement

Anthropic has shipped an official Claude Code plugin under the slash-command namespace design, which collides with this plugin's /design:* commands. Users who install Anthropic's plugin alongside this one see ambiguous skill resolution, and the /design: namespace can no longer be considered ours to claim.

Separately, the discipline this plugin codifies — ADRs, paired spec/design docs, requirements with scenarios, drift detection — is now widely referred to in the industry as "spec-driven development" (SDD). Adopting that name is both clearer to newcomers and aligned with how the practice is discussed.

Decision Drivers

• Namespace collision: /design:* ships with Anthropic's tooling; we cannot keep using it without breaking users
• Industry convention: "spec-driven development" is the established name for this practice
• Breaking change tolerance: All artifacts in this repo are still in proposed/accepted ADRs and draft specs; there is no large external user base whose existing automation would break catastrophically
• GitHub repo naming: Repos under the claude-plugin-* convention should keep that prefix

Considered Options

• Option 1: Keep /design:*, accept the collision (rely on user-side disambiguation)
• Option 2: Rename to sdd everywhere — namespace, repo, plugin name, config heading
• Option 3: Rename only the slash namespace to sdd, keep the repo name claude-plugin-design

Decision Outcome

Chosen option: Option 2 — full rename to sdd. Half-renames are confusing; aligning every surface (namespace, repo, package, configuration heading) avoids ongoing user friction.

Concretely:

Surface	Before	After
Slash command namespace	/design:*	/sdd:*
Plugin name field	design	sdd
GitHub repo	joestump/claude-plugin-design	joestump/claude-plugin-sdd
Local dir convention	claude-plugin-design/	claude-plugin-sdd/
Marketplace name	claude-plugin-design	claude-plugin-sdd
Docusaurus build plugin dir	templates/integration/sync-design-docs/	templates/integration/sync-spec-docs/
Docusaurus manifest file	.design-docs.json	.sdd-docs.json
CLAUDE.md config heading	### Design Plugin Configuration	### SDD Configuration
CLAUDE.md skills heading	### Design Plugin Skills	### SDD Skills
Project title (docs site)	Claude Plugin: Design	Claude Plugin: Spec-Driven Development
Plugin version	3.0.0	4.0.0 (breaking)

The legacy .claude-plugin-design.json config file is removed. Per 📝 ADR-0015, configuration moved to CLAUDE.md, and /sdd:init already auto-migrates any remaining JSON files it discovers in user repos. The migration logic continues to look for the old filename so users upgrading from v3 still get a clean migration path.

GitHub provides automatic redirects from the old repo URL to the new one, so existing clones (origin URLs) keep working until users update them.

Positive Consequences

• No more namespace collision with Anthropic's design plugin
• Plugin name aligns with the industry term "spec-driven development"
• All surfaces (namespace, repo, headings, config) are consistent

Negative Consequences

• Users on v3 must reinstall under the new namespace; their existing ### Design Plugin Configuration sections will not be parsed by v4 skills
  • Mitigation: /sdd:init rewrites the heading on first run
• GitHub repo rename invalidates external links (e.g., docs site links from third-party blog posts)
  • Mitigation: GitHub auto-redirects URLs and clones; published docs site stays on old BASE_URL until next deploy
• Any user-authored governing comments referencing /design:* commands become slightly stale, but remain readable

Links

• Supersedes the implicit naming established in 📝 ADR-0003 (Foundational Design Artifact Formats and Core Skills)
• Related to 📝 ADR-0015 (Markdown-Native Configuration) — the renamed ### SDD Configuration heading is what migrated config writes