diff --git a/build.mjs b/build.mjs
index 26ae01c..6cb79e6 100644
--- a/build.mjs
+++ b/build.mjs
@@ -1,4 +1,4 @@
-import { rm, mkdir, readdir } from "node:fs/promises";
+import { rm, mkdir, cp } from "node:fs/promises";
 import { join } from "node:path";
 
 const DIST = "dist";
@@ -21,7 +21,7 @@ async function build() {
     minify: true,
     sourcemap: "external",
     target: "browser",
-    external: ["/lib/*"], 
+    external: ["/lib/*", "*/zerocms_tagger.js", "*/zerocms_tagger_bg.wasm"],
   });
 
   if (!result.success) {
@@ -31,12 +31,7 @@ async function build() {
 
   // 3. Copy Static Libraries
   console.log("📂 Copying libraries...");
-  const libs = await readdir("lib");
-  for (const lib of libs) {
-    const src = join("lib", lib);
-    const dest = join(DIST, "lib", lib);
-    await Bun.write(dest, Bun.file(src));
-  }
+  await cp("lib", join(DIST, "lib"), { recursive: true });
 
   // Extract the generated hashed file name from Bun's output
   const jsOutput = result.outputs.find(out => out.path.endsWith('.js'));
diff --git a/serve.js b/serve.js
index 0fe3dcc..a294666 100644
--- a/serve.js
+++ b/serve.js
@@ -334,16 +334,22 @@ const server = http.createServer((req, res) => {
   }
 });
 
-server.listen(PORT, () => {
-  console.log(`\x1b[32m[ZeroCMS] Server running at http://localhost:${PORT}\x1b[0m`);
-  console.log(`\x1b[33mOpen http://localhost:${PORT} to start the CMS.\x1b[0m`);
-  if (CLIENT_ID === 'YOUR_CLIENT_ID') {
-    console.log(`\x1b[31m[!] GITHUB_CLIENT_ID is not configured. OAuth will not work.\x1b[0m`);
-  }
-  if (!APP_ID) {
-    console.log(`\x1b[33m[!] GITHUB_APP_ID not found. Organization support disabled.\x1b[0m`);
-  }
-  if (!PRIVATE_KEY) {
-    console.log(`\x1b[33m[!] GITHUB_PRIVATE_KEY not found. Organization support disabled.\x1b[0m`);
-  }
-});
+if (require.main === module) {
+  server.listen(PORT, () => {
+    console.log(`\x1b[32m[ZeroCMS] Server running at http://localhost:${PORT}\x1b[0m`);
+    console.log(`\x1b[33mOpen http://localhost:${PORT} to start the CMS.\x1b[0m`);
+    if (CLIENT_ID === 'YOUR_CLIENT_ID') {
+      console.log(`\x1b[31m[!] GITHUB_CLIENT_ID is not configured. OAuth will not work.\x1b[0m`);
+    }
+    if (!APP_ID) {
+      console.log(`\x1b[33m[!] GITHUB_APP_ID not found. Organization support disabled.\x1b[0m`);
+    }
+    if (!PRIVATE_KEY) {
+      console.log(`\x1b[33m[!] GITHUB_PRIVATE_KEY not found. Organization support disabled.\x1b[0m`);
+    }
+  });
+}
+
+if (typeof module !== 'undefined') {
+  module.exports.base64Url = base64Url;
+}
diff --git a/tests/serve.test.js b/tests/serve.test.js
new file mode 100644
index 0000000..748a0d9
--- /dev/null
+++ b/tests/serve.test.js
@@ -0,0 +1,30 @@
+const { test, expect } = require("bun:test");
+const { base64Url } = require("../serve.js");
+
+test("base64Url handles standard string", () => {
+  expect(base64Url("hello world")).toBe("aGVsbG8gd29ybGQ");
+});
+
+test("base64Url handles empty string", () => {
+  expect(base64Url("")).toBe("");
+});
+
+test("base64Url replaces + with -", () => {
+  // String.fromCharCode(0, 190) creates a string whose standard base64 encoding contains '+'
+  // The standard base64 is AMK+
+  const input = String.fromCharCode(0, 190);
+  expect(base64Url(input)).toBe("AMK-");
+});
+
+test("base64Url replaces / with _", () => {
+  // String.fromCharCode(128, 63) creates a string whose standard base64 encoding contains '/'
+  // The standard base64 is woA/
+  const input = String.fromCharCode(128, 63);
+  expect(base64Url(input)).toBe("woA_");
+});
+
+test("base64Url removes =", () => {
+  // 'a' has standard base64 encoding 'YQ=='
+  // The two '=' should be removed
+  expect(base64Url("a")).toBe("YQ");
+});