Install Codex Design.

01 / Before you install

You need Codex with plugin support, the Codex CLI, Git, and Node.js 22.12 or later in the MCP process PATH. Check these before installing:

codex plugin --help
git --version
node --version

The default package targets macOS and Linux. A PowerShell launcher and .mcp.windows.json are included for native Windows, but Windows has not been verified end to end. Explain this limitation before making platform-specific changes.

02 / Instructions for your agent

The plugin is distributed through the public ummydev/codexdesign Git marketplace on main. No GitHub account or private repository access is required.

Install from this remote repository’s Git marketplace. Run the following commands in order:

codex plugin marketplace add ummydev/codexdesign --ref main
codex plugin add codexdesign@codexdesign-github
codex plugin list

The public repository is ummydev/codexdesign. The plugin identifier is codexdesign, and the marketplace name is codexdesign-github. Its release lives in plugins/codexdesign/ on main.

If the marketplace already exists, inspect codex plugin marketplace list, confirm the repository and branch match, and use:

codex plugin marketplace upgrade codexdesign-github
codex plugin add codexdesign@codexdesign-github
codex plugin list

If you installed an earlier private preview from ummydev/codexcanvas, follow the marketplace migration in the plain-text guide. Confirm the plugin is installed and enabled. Report its version if available. If a required command fails, report the command and error without claiming success.

• Use the remote Git marketplace, not a local development checkout or personal marketplace.
• Do not run npm install, npm ci, or any build command in the workspace, marketplace snapshot, or plugin cache.
• Do not manually install React Flow or other dependencies. The plugin includes its prebuilt MCP server and frontend.
• Do not clone into the personal marketplace or build from source to bypass an error.
• If a prerequisite is missing, explain what is missing. Do not silently install another runtime.
• Preserve the user's canvas projects and settings.

03 / Restart, then create

After installation, completely quit and restart Codex. Open a new conversation so the plugin’s skills and tools can load, then try:

Use Codex Design to explore three directions for a login page
and open the canvas.

Agents: remind the user to restart. Do not assume the current conversation already has the new tools. Create a separate task only if the user explicitly asks and the host supports it.

Keeping your workspace up to date

The canvas daemon runs independently of Codex. Before updating, if an old Codex Design daemon is running, locate the installed plugin and run node scripts/start.cjs stop from its directory. Refresh the marketplace and reinstall using the commands above, then restart Codex and open a new conversation.

No extra API key. Your work stays yours.

There is no separate plugin token wallet. Codex access, plan limits, and applicable usage charges still apply. This is not unlimited free model usage.

Canvas projects and assets are stored locally, by default in ~/.codex-design-plugin/projects. This does not change how Codex processes context or files you share with it. Updating the plugin does not require deleting project data.