Install Chromium

Plumb drives Chrome or Chromium through the Chrome DevTools Protocol. The browser is not bundled with the plumb binary.

Plumb supports Chromium major versions 131 through 150 inclusive. If the detected browser reports a major version outside that range, plumb lint exits with an unsupported Chromium error instead of producing lint output.

macOS

Install Chrome or Chromium:

brew install --cask google-chrome

Plumb checks common app locations such as:

/Applications/Google Chrome.app/Contents/MacOS/Google Chrome
/Applications/Chromium.app/Contents/MacOS/Chromium

To use a specific binary:

plumb lint https://example.com --executable-path "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"

Linux

Install Chromium from your distribution packages:

sudo apt-get update
sudo apt-get install chromium

Package names vary by distribution. On Debian or Ubuntu systems the binary is usually chromium, chromium-browser, or google-chrome-stable.

To use a specific binary:

plumb lint https://example.com --executable-path /usr/bin/chromium

Windows

Install Chrome from the official installer, or install Chromium with a package manager you already use. Plumb checks the standard Chrome app registration and common install paths.

To use a specific binary:

plumb lint https://example.com --executable-path "C:\Program Files\Google\Chrome\Application\chrome.exe"

Check the version

Run the browser directly to confirm its major version:

chromium --version

The first number in the version must fall in the supported range (131 through 150 inclusive). If you have several Chrome or Chromium builds installed, pass --executable-path to select one whose major version falls in that range.

Auto-fetch (opt-in)

If you do not have a system Chromium installed, pass --auto-fetch-chromium and Plumb downloads Chrome-for-Testing into a managed cache directory before the first lint run. Subsequent runs reuse the cached binary.

plumb lint https://example.com --auto-fetch-chromium

The cache directory follows the platform convention:

After the first install, Plumb writes a .plumb-sha256 file alongside the executable. Every subsequent run re-hashes the binary and refuses to launch on a mismatch — the cache is pinned against accidental or malicious tampering.

Trust model

Auto-fetch downloads and executes a third-party binary. Chromium is served by Google over HTTPS but Plumb does not verify the upstream publisher signature, so passing --auto-fetch-chromium is your explicit acknowledgement of trust. The SHA-256 sidecar protects against post-install tampering, not against a compromised upstream. If the trust model is unacceptable for your environment, install Chromium yourself and pass --executable-path instead.