diff --git a/Formula/wai.rb b/Formula/wai.rb
new file mode 100644
index 0000000..605d295
--- /dev/null
+++ b/Formula/wai.rb
@@ -0,0 +1,39 @@
+class Wai < Formula
+  desc "WAI, an open media standard: its command line, and a local relay and room service"
+  homepage "https://wai.transaction.science/docs/quickstart/"
+  version "0.4.0"
+  license "Apache-2.0"
+  on_macos do
+    on_arm do
+      url "https://git.transaction.science/Transaction-Science/open-standards/releases/download/wai-v0.4.0/wai-0.4.0-aarch64-apple-darwin.tar.gz"
+      sha256 "bd86291604a444208bbd39ad02739a7fcff5f286db32fa7175cd06d39bc5d793"
+    end
+    on_intel do
+      url "https://git.transaction.science/Transaction-Science/open-standards/releases/download/wai-v0.4.0/wai-0.4.0-x86_64-apple-darwin.tar.gz"
+      sha256 "1a4a734d7845ffab9a4d53eb478370ab51b1f4de03fef5f667207fa2993939b0"
+    end
+  end
+  on_linux do
+    on_arm do
+      url "https://git.transaction.science/Transaction-Science/open-standards/releases/download/wai-v0.4.0/wai-0.4.0-aarch64-unknown-linux-musl.tar.gz"
+      sha256 "0ea60ffb5dfd82cd8c5f70ce37631a4e052c2a50675f87143a49630d104cadb0"
+    end
+    on_intel do
+      url "https://git.transaction.science/Transaction-Science/open-standards/releases/download/wai-v0.4.0/wai-0.4.0-x86_64-unknown-linux-musl.tar.gz"
+      sha256 "9cf15a8ce823e22469b9d99147e36d2ea897c5a4e9fd040fa8e0357ec163cf29"
+    end
+  end
+
+  def install
+    # bin/ and share/wai/web/ side by side: `wai dev` finds the relay, the room service and the
+    # room client beside its own binary.
+    bin.install Dir["bin/*"]
+    (share/"wai").install "share/wai/web"
+  end
+
+  test do
+    assert_match "video-room", shell_output("#{bin}/wai create --list")
+    assert_match "delivered-verified", shell_output("#{bin}/wai hello #{testpath}/hello")
+    assert_match "verified", shell_output("#{bin}/wai verify #{testpath}/hello")
+  end
+end
diff --git a/README.md b/README.md
index 6f9a948..6f8498a 100644
--- a/README.md
+++ b/README.md
@@ -42,3 +42,20 @@ Intel; Linux on x86_64 and arm64, linked statically.
 Homepage: https://wai.transaction.science/quantum-studio/
 Source: https://git.transaction.science/Transaction-Science/open-standards/src/branch/main/wai/wai-quantum-cli
 Releases: https://git.transaction.science/Transaction-Science/open-standards/releases (tags `wai-quantum-cli-v…`)
+
+## wai
+
+The WAI command line, and what `wai dev` runs on your own machine: a relay, a room service, the
+room client a browser loads, a remote desktop host and the packager. `wai hello` shows WAI's
+four steps on a sample; `wai create` makes a project from one of the examples; `wai dev` runs it.
+
+```sh
+brew tap transaction-science/tap https://git.transaction.science/Transaction-Science/homebrew-tap
+brew install transaction-science/tap/wai
+wai hello
+```
+
+macOS and Linux, arm64 and x86_64.
+
+Homepage: https://wai.transaction.science/docs/quickstart/
+Source and releases: https://git.transaction.science/Transaction-Science/open-standards