diff --git a/packages/cli/src/__tests__/cloud-init.test.ts b/packages/cli/src/__tests__/cloud-init.test.ts
new file mode 100644
index 00000000..b5100c5d
--- /dev/null
+++ b/packages/cli/src/__tests__/cloud-init.test.ts
@@ -0,0 +1,106 @@
+import { describe, it, expect } from "bun:test";
+import { getPackagesForTier, needsNode, needsBun, NODE_INSTALL_CMD } from "../shared/cloud-init.js";
+
+describe("getPackagesForTier", () => {
+  const MINIMAL_PACKAGES = [
+    "curl",
+    "unzip",
+    "git",
+    "ca-certificates",
+  ];
+
+  it("returns minimal packages for 'minimal' tier", () => {
+    const pkgs = getPackagesForTier("minimal");
+    expect(pkgs).toEqual(MINIMAL_PACKAGES);
+  });
+
+  it("returns minimal + zsh + build-essential for 'node' tier", () => {
+    const pkgs = getPackagesForTier("node");
+    for (const p of MINIMAL_PACKAGES) {
+      expect(pkgs).toContain(p);
+    }
+    expect(pkgs).toContain("zsh");
+    expect(pkgs).toContain("build-essential");
+  });
+
+  it("returns minimal + zsh but NOT build-essential for 'bun' tier", () => {
+    const pkgs = getPackagesForTier("bun");
+    for (const p of MINIMAL_PACKAGES) {
+      expect(pkgs).toContain(p);
+    }
+    expect(pkgs).toContain("zsh");
+    expect(pkgs).not.toContain("build-essential");
+  });
+
+  it("returns minimal + zsh + build-essential for 'full' tier", () => {
+    const pkgs = getPackagesForTier("full");
+    for (const p of MINIMAL_PACKAGES) {
+      expect(pkgs).toContain(p);
+    }
+    expect(pkgs).toContain("zsh");
+    expect(pkgs).toContain("build-essential");
+  });
+
+  it("defaults to 'full' tier when no argument given", () => {
+    expect(getPackagesForTier()).toEqual(getPackagesForTier("full"));
+  });
+});
+
+describe("needsNode", () => {
+  it("returns true for 'node' tier", () => {
+    expect(needsNode("node")).toBe(true);
+  });
+
+  it("returns true for 'full' tier", () => {
+    expect(needsNode("full")).toBe(true);
+  });
+
+  it("returns false for 'minimal' tier", () => {
+    expect(needsNode("minimal")).toBe(false);
+  });
+
+  it("returns false for 'bun' tier", () => {
+    expect(needsNode("bun")).toBe(false);
+  });
+
+  it("defaults to true (full tier)", () => {
+    expect(needsNode()).toBe(true);
+  });
+});
+
+describe("needsBun", () => {
+  it("returns true for 'bun' tier", () => {
+    expect(needsBun("bun")).toBe(true);
+  });
+
+  it("returns true for 'full' tier", () => {
+    expect(needsBun("full")).toBe(true);
+  });
+
+  it("returns false for 'minimal' tier", () => {
+    expect(needsBun("minimal")).toBe(false);
+  });
+
+  it("returns false for 'node' tier", () => {
+    expect(needsBun("node")).toBe(false);
+  });
+
+  it("defaults to true (full tier)", () => {
+    expect(needsBun()).toBe(true);
+  });
+});
+
+describe("NODE_INSTALL_CMD", () => {
+  it("is a non-empty string", () => {
+    expect(typeof NODE_INSTALL_CMD).toBe("string");
+    expect(NODE_INSTALL_CMD.length).toBeGreaterThan(0);
+  });
+
+  it("installs Node 22", () => {
+    expect(NODE_INSTALL_CMD).toContain("22");
+  });
+
+  it("downloads and runs an install script", () => {
+    expect(NODE_INSTALL_CMD).toContain("curl");
+  });
+});