diff --git a/package.json b/package.json
index 7730d0c..8c25e4e 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,9 @@
   "version": "1.0.0",
   "description": "REST API for managing notes with tags and search — demo project for Agentic AI Workshop (Advanced)",
   "main": "dist/index.js",
+  "bin": {
+    "fleet-e2e-toy": "dist/cli.js"
+  },
   "scripts": {
     "build": "tsc",
     "start": "ts-node src/index.ts",
diff --git a/src/cli.ts b/src/cli.ts
new file mode 100644
index 0000000..e40e0d4
--- /dev/null
+++ b/src/cli.ts
@@ -0,0 +1,67 @@
+const VERSION = "fleet-e2e-toy v1.0.0";
+
+const HELP_TEXT = `Usage: fleet-e2e-toy [command] [options] [arguments]
+
+Commands:
+  help                Show this help message
+  serve               Start the API server (default)
+
+Flags:
+  --version, -v       Print version and exit
+  --help, -h          Show this help message
+  --port <number>     Port to listen on (default: 3000)`;
+
+export function parseArgs(argv: string[]): { action: string; args: string[] } {
+  const args = argv.slice(2);
+
+  if (args.includes("--version") || args.includes("-v")) {
+    return { action: "version", args: [] };
+  }
+
+  if (args.includes("--help") || args.includes("-h") || args[0] === "help") {
+    return { action: "help", args: [] };
+  }
+
+  const positional = args.filter((a) => !a.startsWith("-"));
+  return { action: "serve", args: positional };
+}
+
+export function validateStringArg(value: string): string | null {
+  if (value.trim().length === 0) {
+    return "Error: argument must not be empty or whitespace-only";
+  }
+  return null;
+}
+
+export function run(argv: string[]): number {
+  const parsed = parseArgs(argv);
+
+  switch (parsed.action) {
+    case "version":
+      console.log(VERSION);
+      return 0;
+
+    case "help":
+      console.log(HELP_TEXT);
+      return 0;
+
+    case "serve": {
+      for (const arg of parsed.args) {
+        const error = validateStringArg(arg);
+        if (error) {
+          console.error(error);
+          return 1;
+        }
+      }
+      return 0;
+    }
+
+    default:
+      return 0;
+  }
+}
+
+if (require.main === module) {
+  const code = run(process.argv);
+  process.exit(code);
+}
diff --git a/tests/cli.test.ts b/tests/cli.test.ts
new file mode 100644
index 0000000..c17bc6d
--- /dev/null
+++ b/tests/cli.test.ts
@@ -0,0 +1,152 @@
+import { parseArgs, validateStringArg, run } from "../src/cli";
+
+describe("parseArgs", () => {
+  it("detects --version flag", () => {
+    expect(parseArgs(["node", "cli", "--version"])).toEqual({ action: "version", args: [] });
+  });
+
+  it("detects -v flag", () => {
+    expect(parseArgs(["node", "cli", "-v"])).toEqual({ action: "version", args: [] });
+  });
+
+  it("detects --version alongside other flags", () => {
+    expect(parseArgs(["node", "cli", "--port", "3000", "--version"])).toEqual({
+      action: "version",
+      args: [],
+    });
+  });
+
+  it("detects --help flag", () => {
+    expect(parseArgs(["node", "cli", "--help"])).toEqual({ action: "help", args: [] });
+  });
+
+  it("detects -h flag", () => {
+    expect(parseArgs(["node", "cli", "-h"])).toEqual({ action: "help", args: [] });
+  });
+
+  it("detects help subcommand", () => {
+    expect(parseArgs(["node", "cli", "help"])).toEqual({ action: "help", args: [] });
+  });
+
+  it("defaults to serve with no args", () => {
+    expect(parseArgs(["node", "cli"])).toEqual({ action: "serve", args: [] });
+  });
+
+  it("collects positional args for serve", () => {
+    expect(parseArgs(["node", "cli", "myarg"])).toEqual({ action: "serve", args: ["myarg"] });
+  });
+});
+
+describe("--version flag (gh-toy-4ef)", () => {
+  it("prints fleet-e2e-toy v1.0.0", () => {
+    const spy = jest.spyOn(console, "log").mockImplementation();
+    const code = run(["node", "cli", "--version"]);
+    expect(code).toBe(0);
+    expect(spy).toHaveBeenCalledWith("fleet-e2e-toy v1.0.0");
+    spy.mockRestore();
+  });
+
+  it("prints version with -v alias", () => {
+    const spy = jest.spyOn(console, "log").mockImplementation();
+    const code = run(["node", "cli", "-v"]);
+    expect(code).toBe(0);
+    expect(spy).toHaveBeenCalledWith("fleet-e2e-toy v1.0.0");
+    spy.mockRestore();
+  });
+
+  it("--version takes priority when mixed with other flags", () => {
+    const spy = jest.spyOn(console, "log").mockImplementation();
+    const code = run(["node", "cli", "--port", "8080", "--version"]);
+    expect(code).toBe(0);
+    expect(spy).toHaveBeenCalledWith("fleet-e2e-toy v1.0.0");
+    spy.mockRestore();
+  });
+});
+
+describe("help command (gh-toy-kbk)", () => {
+  it("--help prints usage and exits 0", () => {
+    const spy = jest.spyOn(console, "log").mockImplementation();
+    const code = run(["node", "cli", "--help"]);
+    expect(code).toBe(0);
+    const output = spy.mock.calls[0][0] as string;
+    expect(output).toContain("Usage:");
+    expect(output).toContain("--version");
+    expect(output).toContain("--help");
+    expect(output).toContain("help");
+    expect(output).toContain("serve");
+    spy.mockRestore();
+  });
+
+  it("-h prints same usage", () => {
+    const spy = jest.spyOn(console, "log").mockImplementation();
+    const code = run(["node", "cli", "-h"]);
+    expect(code).toBe(0);
+    const output = spy.mock.calls[0][0] as string;
+    expect(output).toContain("Usage:");
+    spy.mockRestore();
+  });
+
+  it("help subcommand prints same usage as --help", () => {
+    const helpSpy = jest.spyOn(console, "log").mockImplementation();
+    run(["node", "cli", "--help"]);
+    const helpOutput = helpSpy.mock.calls[0][0];
+    helpSpy.mockRestore();
+
+    const subSpy = jest.spyOn(console, "log").mockImplementation();
+    run(["node", "cli", "help"]);
+    const subOutput = subSpy.mock.calls[0][0];
+    subSpy.mockRestore();
+
+    expect(subOutput).toBe(helpOutput);
+  });
+
+  it("help output lists all subcommands and flags", () => {
+    const spy = jest.spyOn(console, "log").mockImplementation();
+    run(["node", "cli", "--help"]);
+    const output = spy.mock.calls[0][0] as string;
+    expect(output).toContain("help");
+    expect(output).toContain("serve");
+    expect(output).toContain("--version");
+    expect(output).toContain("-v");
+    expect(output).toContain("--help");
+    expect(output).toContain("-h");
+    expect(output).toContain("--port");
+    spy.mockRestore();
+  });
+});
+
+describe("input validation (gh-toy-v6z)", () => {
+  it("validateStringArg rejects empty string", () => {
+    expect(validateStringArg("")).not.toBeNull();
+  });
+
+  it("validateStringArg rejects whitespace-only string", () => {
+    expect(validateStringArg("   ")).not.toBeNull();
+    expect(validateStringArg("\t\n")).not.toBeNull();
+  });
+
+  it("validateStringArg accepts valid string", () => {
+    expect(validateStringArg("hello")).toBeNull();
+  });
+
+  it("run exits non-zero on empty string argument", () => {
+    const spy = jest.spyOn(console, "error").mockImplementation();
+    const code = run(["node", "cli", ""]);
+    expect(code).toBe(1);
+    expect(spy).toHaveBeenCalledWith(expect.stringContaining("empty or whitespace"));
+    spy.mockRestore();
+  });
+
+  it("run exits non-zero on whitespace-only argument", () => {
+    const spy = jest.spyOn(console, "error").mockImplementation();
+    const code = run(["node", "cli", "   "]);
+    expect(code).toBe(1);
+    expect(spy).toHaveBeenCalledWith(expect.stringContaining("empty or whitespace"));
+    spy.mockRestore();
+  });
+
+  it("run exits 0 on valid string argument", () => {
+    const code = run(["node", "cli", "validarg"]);
+    expect(code).toBe(0);
+  });
+});