Developer toolchain (devkit)

The devkit installs the developer tools that SigmaShake agents use. It is part of ssg init. You can also run it on its own.

The devkit needs an active SigmaShake license. You get a license when you have an active subscription. See Plans and limits.

What it installs

Tool	Pinned version	Minimum version on PATH	Notes
Node.js	24.22.0	22.0.0
Bun	1.4.3	1.0.0
GitHub CLI (gh)	2.102.0	2.0.0	You run gh auth login yourself.
wrangler	4.151.1	4.0.0	You run wrangler login yourself.
Playwright	1.64.1	1.0.0	Installs Chromium.
Playwright MCP	0.0.83	None	Gives agents a browser tool.
stk, headroom, wt	Same release as ssg	Any version	SigmaShake agent tools.
Claude in Chrome	None	None	Guided step. See Claude in Chrome.

If a tool on PATH is older than the minimum version, the devkit installs its own copy.

Run ssg devkit status to see the install state of each tool. Pass tool IDs to --only to limit an install.

Tool IDs

Use these IDs with --only:

ID	Tool
node	Node.js
bun	Bun
gh	GitHub CLI
wrangler	wrangler
playwright	Playwright
chromium	Playwright Chromium
playwright-mcp	Playwright MCP server
claude-plugin	Claude Code plugin sigmashake-devkit
claude-chrome	Claude in Chrome (guided step)
stk	SigmaShake agent tool stk
headroom	SigmaShake agent tool headroom
wt	SigmaShake agent tool wt

Check the toolchain

ssg devkit status           # table of tools, versions, and install state
ssg devkit status --json    # same data as JSON

ssg devkit status makes no network call. It needs no license.

Install the toolchain

ssg devkit install                       # install every tool that is missing
ssg devkit install --only <id>,<id>      # install only the listed tool IDs
ssg devkit install --dry-run             # show the plan and change nothing
ssg devkit install --yes                 # do not ask for confirmation
ssg devkit install --json                # machine-readable output (implies --yes)

The devkit does not need sudo. It keeps its state under ~/.sigmashake/devkit. On Windows, the state folder is %USERPROFILE%\.sigmashake\devkit.

The devkit puts the tool binaries in the folder of ssg in these cases:

• The folder is under your home folder.
• You can write to the folder.
• The folder is not inside a node_modules folder.

Otherwise, the devkit puts the tool binaries in ~/.sigmashake/devkit/bin. On Windows, that folder is %USERPROFILE%\.sigmashake\devkit\bin. Run ssg devkit status --json and read the field bin_dir to see the folder that the devkit plans to use.

If a tool is already on PATH at a version that meets the minimum, the devkit keeps it. Its status is external. It does not replace that tool, and it needs no action.

Before the devkit uses an archive, it checks the archive against a pinned SHA-256 value. If the check fails, the devkit stops and does not use the file.

When the devkit runs

ssg init runs the devkit by default. It runs after ssg init configures your agent hosts.

Skip the devkit in any of these ways:

• Run ssg init --no-devkit.
• Set the environment variable SSG_DEVKIT=off.
• Run in CI: the devkit does not run if the environment variable CI is set.

Sign in first

The devkit needs an active license. If you run ssg init before you sign in, the devkit waits. It finishes automatically after your first sign-in.

You can also sign in and then install the devkit:

ssg auth login
ssg devkit install

ssg auth login is the sign-in command in the CLI reference.

For sign-in options, see Signing in.

Agent host setup

The devkit sets up the Playwright MCP server for each agent host.

• Claude Code: ssg adds the local plugin marketplace sigmashake. It installs the plugin sigmashake-devkit. The plugin gives the Playwright MCP server.
• Codex, Cursor, Antigravity, OpenCode, and Pi: ssg adds a playwright MCP server entry. It does not replace a playwright entry that the user wrote.

The devkit records each MCP entry that it writes. The record is the file hosts-authored.json in the devkit root. The devkit updates only an entry that it wrote. If an entry matches the current command exactly, the devkit treats it as its own entry. An entry from before the record is not in the record. Remove that entry by hand once. Then run ssg devkit install. The devkit writes the entry again.

Claude in Chrome

Claude in Chrome is a guided step. The devkit does not install it for you.

1. Install the extension from the Chrome Web Store.
2. Run claude --chrome to use Chrome in one session.
3. To use Chrome in each session, run /chrome in Claude Code and select "Enabled by default".

ssg never changes the Claude Code settings files.

Logins you do yourself

The devkit does not log in to these services. Run these commands yourself:

gh auth login
wrangler login

Linux: Chromium system libraries

If Chromium needs system libraries, run this command. It needs sudo:

sudo npx [email protected] install-deps chromium

Troubleshooting

• Run ssg devkit status --json to see which tool fails.
• Run ssg devkit install --dry-run to see the planned changes.
• Run ssg devkit install --only <id> to retry one tool.
• If the SHA-256 check fails, the devkit does not use the file. Run ssg doctor, then send the output to the support portal.