Install

SDCD comes in two layers. You can install the core rules alone, or the rules plus the plugin.

Layer 1 — Core rules (every install gets these)

The core rules at ~/.claude/CLAUDE.md are loaded in every Claude Code session automatically. That makes the §1 discipline opt-out, not opt-in — which is the point.

Windows (PowerShell)

git clone https://github.com/Tschonsen/spec-driven-claude-development.git
cd spec-driven-claude-development
.\install.ps1

macOS / Linux

git clone https://github.com/Tschonsen/spec-driven-claude-development.git
cd spec-driven-claude-development
./install.sh

The installer:

Backs up any existing ~/.claude/CLAUDE.md or ~/.claude/methodology.md to .bak files.
Copies CLAUDE.md and methodology.md into ~/.claude/.
Does not touch project-specific files. Each project is still free to add its own <project>/CLAUDE.md.

After this, every Claude Code session you start will have the §1 rules loaded. That is the minimum viable SDCD install.

Layer 2 — The plugin (optional but recommended for serious projects)

The plugin bundles the methodology as namespaced slash-commands (/sdcd:*) and specialised subagents. You can use SDCD without it — but you’ll manually do what the plugin automates.

Testing the plugin locally

claude --plugin-dir path/to/spec-driven-claude-development/plugin/sdcd

Then in a Claude Code session:

/plugins

You should see sdcd listed with its 11 skills and 8 subagents.

Installing the plugin persistently

Once you are happy with the behaviour, install the plugin into your Claude Code config:

claude plugin install ./plugin/sdcd

Verify:

claude plugin list

The plugin will now be available in every session without the --plugin-dir flag.

Verifying the install

In a new Claude Code session, check that §1.6 (Brain Files) is loaded:

Ask Claude: “Show me §1.6 from the core rules.”

You should get the Brain-File convention text back. If Claude has no idea what §1.6 is, the install did not land; check the installer output.

If the plugin is installed, try:

/sdcd:new-project

Claude should recognise the skill and ask for the project intent.

Uninstalling

Core rules

rm ~/.claude/CLAUDE.md ~/.claude/methodology.md
# restore your backups if you had them:
mv ~/.claude/CLAUDE.md.bak ~/.claude/CLAUDE.md
mv ~/.claude/methodology.md.bak ~/.claude/methodology.md

Plugin

claude plugin uninstall sdcd

Updating

From the repo checkout:

git pull
./install.sh   # or install.ps1 on Windows
claude plugin update sdcd

The installer always creates fresh .bak copies before overwriting, so you can roll back if an update breaks your workflow.

Customisation

SDCD is opinionated, but it is not yours until you fork it. Two paths:

Fork and edit — clone your own copy, change rules to match your style, install from your fork.
Project-level overrides — keep the user-level SDCD as-is, override specific rules in <project>/CLAUDE.md. Every project can declare its own state-file tier and opt out of specific rules with a reason.