Sdd

SDD Plugin — Spec-Driven Development for Claude Code

SDD is a Claude Code plugin that guides you through a structured, interview-driven workflow for planning and building software projects. It replaces ad-hoc prompting with a repeatable process: scope the project, produce a product requirements document, write a technical spec, then execute in sprint cycles with built-in retrospectives. Every phase produces real Markdown artifacts in your repository, so the project's knowledge base grows alongside the code.

Installation

From a plugin marketplace

# Add the marketplace (one-time)
/plugin marketplace add zabuuq/sdd-plugin

# Install the plugin
/plugin install sdd@sdd-marketplace

Local development

# Clone the repository, then run Claude Code with the plugin directory
claude --plugin-dir ./plugins/sdd

Commands

SDD provides 13 commands organized into four workflow phases.

Planning Phase

Command	Description
/sdd:onboard	One-time setup. Creates a global user profile with your communication style, git preferences, and workflow explanation preference.
/sdd:discovery	Open exploration before structural decisions. Reads files placed in docs/refs/ and runs an interview to capture "what is this?"
/sdd:scope	Defines the project boundary — what's in, what's out. Narrower in v2; exploration moved to /sdd:discovery.
/sdd:prd	Produces a product requirements document from the scope. User stories grouped into epics with testable acceptance criteria.
/sdd:spec	Generates a technical specification covering architecture, data models, and file structure. Also produces CLAUDE.md and AGENTS.md for your project.

Sprint Loop

Command	Description
/sdd:plan	Pulls a logical batch of work from the PRD into a buildable sprint checklist with spec references and verification steps.
/sdd:build	Executes the sprint checklist. Supports step-by-step mode (one item per session) and autonomous mode (multiple items with checkpoints). Wraps up with PRD checkoff, story splitting, and a "anything notable?" beat that closes the sprint.
/sdd:polish	Optional post-sprint cleanup. Scopes bugs, features, or UX improvements through a brief interview and appends them to the sprint.
/sdd:refine	Runs unvetted PRD items through a compressed planning interview. Updates spec and related documents if needed.

Project Close

Command	Description
/sdd:retro	Project-level retrospective across all sprints. Synthesizes patterns and explains how to act on plugin feedback.

Anytime

Command	Description
/sdd:pause	Distill the in-flight command's conversation into a resume file at docs/<command>-resume.md for multi-session resume.
/sdd:unpause	Zero-argument resume of whatever was paused — reads lastCommand, loads the matching resume file, and picks up.
/sdd:feedback	Quick flag for plugin improvement ideas. Captures your note with context and returns immediately. Usage: /sdd:feedback [your note]

Workflow

Planning Phase       /sdd:onboard → /sdd:discovery → /sdd:scope → /sdd:prd → /sdd:spec

Sprint Loop          /sdd:plan → /sdd:build → /sdd:polish (optional) → /sdd:refine (if unvetted items)
                         ↑                                                                   │
                         └──────────────────── loop back ────────────────────────────────────┘

Project Close        /sdd:retro

Anytime              /sdd:pause, /sdd:unpause, /sdd:feedback

The planning phase runs once per project. You move through each command in order, and each one builds on the artifacts produced by the previous command.

The sprint loop repeats as many times as needed. Each cycle plans a batch of work, builds it (with /sdd:build closing the sprint in its wrap-up phase), optionally polishes via /sdd:polish, and runs /sdd:refine against any unvetted items that emerged. After the loop, you return to /sdd:plan for the next batch.

/sdd:retro runs once when the project is complete. It reads all sprint process notes to produce a project-level summary and captures cross-project patterns to your user profile.

/sdd:pause and /sdd:unpause are anytime utilities for suspending and resuming the current command across sessions. /sdd:feedback can be used at any point to flag ideas for improving the plugin itself.

Quick Start

1. Install the plugin using one of the methods above.

2. Run onboard to set up your user profile:

   /sdd:onboard
   

3. Start a project by navigating to your project directory and running scope:

   /sdd:scope
   

   If you have initial ideas written up, place them in docs/seed.md before running /sdd:scope and they will be used as starting context.

4. Continue through the planning phase in order:

   /sdd:prd
   /sdd:spec
   

5. Enter the sprint loop:

   /sdd:plan
   /sdd:build
   

6. Optionally polish and refine after each sprint, then loop back to /sdd:plan for the next one.

Artifacts

SDD creates the following files in your project:

Project documents (in docs/)

File	Created by
scope.md	/sdd:scope
prd.md	/sdd:prd
spec.md	/sdd:spec
sprint-N.md	/sdd:plan
backlog.md	All planning commands (overflow items)
open-concerns.md	/sdd:scope (updated by every command)
project-state.json	/sdd:scope (updated by every command)
sdd-feedback.md	/sdd:feedback
retro.md	/sdd:retro

Project root files

File	Created by
CLAUDE.md	/sdd:spec
AGENTS.md	/sdd:spec
README.md	/sdd:spec
process-notes.md	Planning phase commands
process-notes-sprint-N.md	Sprint loop commands (/sdd:plan, /sdd:build, /sdd:polish, /sdd:refine)

Global files

File	Created by
~/.claude/sdd-user-profile.json	/sdd:onboard

License

MIT

Attribution

Adapted from the hackathon-in-a-plugin curriculum by Devpost.