diff --git a/scripts/build.ts b/scripts/build.ts
index 985408b..7a6fa9c 100644
--- a/scripts/build.ts
+++ b/scripts/build.ts
@@ -79,9 +79,9 @@ const swSource = await swBuild.outputs[0]!.text();
 const precachePaths = precachePathsFromOutputs(
   shellBuild.outputs.map((output) => relative(DIST, output.path)),
   [
-    "/inference.worker.js",
-    "/manifest.webmanifest",
-    ...ICON_SIZES.map((size) => `/icons/icon-${size}.png`),
+    "inference.worker.js",
+    "manifest.webmanifest",
+    ...ICON_SIZES.map((size) => `icons/icon-${size}.png`),
   ],
 );
 const version = Bun.hash(
diff --git a/src/App.tsx b/src/App.tsx
index 70a47fc..342c08b 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -120,7 +120,7 @@ export function App() {
     // main thread (Architecture.md §5). The worker script is bundled by the
     // server at startup and served at a stable URL (see src/index.ts) because
     // Bun's bundler does not follow `new Worker(new URL(...))` graphs yet.
-    const worker = new Worker("/inference.worker.js", { type: "module" });
+    const worker = new Worker("inference.worker.js", { type: "module" });
     worker.addEventListener("message", (event: MessageEvent<unknown>) => {
       const message = event.data;
       if (!isWorkerToUiMessage(message)) return;
diff --git a/src/lib/authClient.ts b/src/lib/authClient.ts
index 49276ad..122c9d7 100644
--- a/src/lib/authClient.ts
+++ b/src/lib/authClient.ts
@@ -122,7 +122,7 @@ export function login(
   password: string,
   fetchFn: FetchLike = defaultFetch,
 ): Promise<AuthUser> {
-  return requestUser(fetchFn, "/api/auth/login", { username, password });
+  return requestUser(fetchFn, "api/auth/login", { username, password });
 }
 
 /** POST /api/auth/register → user (auto signed in), or throws (400/409). */
@@ -131,7 +131,7 @@ export function register(
   password: string,
   fetchFn: FetchLike = defaultFetch,
 ): Promise<AuthUser> {
-  return requestUser(fetchFn, "/api/auth/register", { username, password });
+  return requestUser(fetchFn, "api/auth/register", { username, password });
 }
 
 /** Result of the startup /me probe (fetchAuthStatus). */
@@ -158,7 +158,7 @@ export async function fetchAuthStatus(
   fetchFn: FetchLike = defaultFetch,
 ): Promise<AuthStatus> {
   try {
-    const response = await fetchFn("/api/auth/me", {
+    const response = await fetchFn("api/auth/me", {
       method: "GET",
       credentials: "same-origin",
     });
@@ -179,7 +179,7 @@ export async function fetchAuthStatus(
  */
 export async function logout(fetchFn: FetchLike = defaultFetch): Promise<void> {
   try {
-    await fetchFn("/api/auth/logout", {
+    await fetchFn("api/auth/logout", {
       method: "POST",
       credentials: "same-origin",
     });
diff --git a/src/lib/engine.ts b/src/lib/engine.ts
index 79c387d..5e6228f 100644
--- a/src/lib/engine.ts
+++ b/src/lib/engine.ts
@@ -263,7 +263,7 @@ export class ServerEngine implements Engine {
 
     let response: Response;
     try {
-      response = await this.fetchFn(`/api/transcribe?${params}`, {
+      response = await this.fetchFn(`api/transcribe?${params}`, {
         method: "POST",
         credentials: "same-origin",
         headers: { "Content-Type": "application/octet-stream" },
@@ -327,7 +327,7 @@ export async function fetchServerEngineStatus(
   fetchFn: FetchLike = defaultFetch,
 ): Promise<ServerEngineStatus> {
   try {
-    const response = await fetchFn("/api/transcribe/status", {
+    const response = await fetchFn("api/transcribe/status", {
       method: "GET",
       credentials: "same-origin",
     });
diff --git a/src/pwa/manifest.webmanifest b/src/pwa/manifest.webmanifest
index 6669a4b..2805eaf 100644
--- a/src/pwa/manifest.webmanifest
+++ b/src/pwa/manifest.webmanifest
@@ -2,21 +2,21 @@
   "name": "Whisper Web — on-device speech-to-text",
   "short_name": "Whisper Web",
   "description": "Speech-to-text that runs entirely in your browser via OpenAI Whisper. Works offline once installed with a downloaded model.",
-  "id": "/",
-  "start_url": "/",
-  "scope": "/",
+  "id": "./",
+  "start_url": "./",
+  "scope": "./",
   "display": "standalone",
   "theme_color": "#16181d",
   "background_color": "#16181d",
   "icons": [
     {
-      "src": "/icons/icon-192.png",
+      "src": "icons/icon-192.png",
       "sizes": "192x192",
       "type": "image/png",
       "purpose": "any maskable"
     },
     {
-      "src": "/icons/icon-512.png",
+      "src": "icons/icon-512.png",
       "sizes": "512x512",
       "type": "image/png",
       "purpose": "any maskable"
diff --git a/src/pwa/precache.ts b/src/pwa/precache.ts
index de498b9..bbc8d7b 100644
--- a/src/pwa/precache.ts
+++ b/src/pwa/precache.ts
@@ -27,7 +27,7 @@ export function precachePathsFromOutputs(
   for (const outputPath of outputPaths) {
     const normalized = outputPath.replaceAll("\\", "/").replace(/^\.?\//, "");
     if (normalized.endsWith(".map")) continue;
-    paths.add(normalized === "index.html" ? "/" : `/${normalized}`);
+    paths.add(normalized === "index.html" ? "./" : normalized);
   }
   for (const extra of extraPaths) paths.add(extra);
   return [...paths].sort();
diff --git a/src/pwa/register.ts b/src/pwa/register.ts
index a4f278d..579ed39 100644
--- a/src/pwa/register.ts
+++ b/src/pwa/register.ts
@@ -31,7 +31,7 @@ export function registerServiceWorker(options: RegisterOptions): void {
   if (container.controller) options.onControlled?.();
 
   container
-    .register("/sw.js")
+    .register("sw.js")
     .then((registration) => {
       const notify = (worker: ServiceWorker) => {
         options.onUpdateReady(() => {
diff --git a/src/pwa/sw.ts b/src/pwa/sw.ts
index 8a5c951..79e5c70 100644
--- a/src/pwa/sw.ts
+++ b/src/pwa/sw.ts
@@ -18,6 +18,7 @@
 // In dev src/index.ts injects an empty list + "dev"; in production
 // scripts/build.ts injects the hashed dist asset list + a content hash.
 const PRECACHE: string[] = JSON.parse("__PRECACHE_MANIFEST__") as string[];
+const PRECACHE_URLS = PRECACHE.map(path => new URL(path, sw.location.href).pathname);
 const VERSION = "__CACHE_VERSION__";
 
 const SHELL_CACHE = `whisper-shell-${VERSION}`;
@@ -118,19 +119,19 @@ sw.addEventListener("fetch", (event) => {
   if (url.origin !== sw.location.origin) return;
   // API is network-only (D-007) — auth and the server engine must never be
   // served stale from cache.
-  if (url.pathname.startsWith("/api/")) return;
+  if (url.pathname.includes("/api/")) return;
 
-  if (url.pathname.startsWith("/ort/")) {
+  if (url.pathname.includes("/ort/")) {
     event.respondWith(cacheFirst(RUNTIME_CACHE, request));
     return;
   }
-  if (PRECACHE.includes(url.pathname)) {
+  if (PRECACHE_URLS.includes(url.pathname)) {
     event.respondWith(cacheFirst(SHELL_CACHE, request));
     return;
   }
   // Anything else (dev's unhashed shell, navigations to deep links):
   // network-first with cache fallback; navigations fall back to the shell.
-  event.respondWith(networkFirst(request, request.mode === "navigate" ? "/" : null));
+  event.respondWith(networkFirst(request, request.mode === "navigate" ? "./" : null));
 });
 
 export {};
diff --git a/src/worker/inference.worker.ts b/src/worker/inference.worker.ts
index 4bf6eb1..be843dd 100644
--- a/src/worker/inference.worker.ts
+++ b/src/worker/inference.worker.ts
@@ -31,7 +31,7 @@ import {
 // them at /ort/* (src/index.ts; copied into dist/ort by scripts/build.ts)
 // and the service worker runtime-caches them cache-first (src/pwa/sw.ts).
 if (env.backends.onnx.wasm) {
-  env.backends.onnx.wasm.wasmPaths = "/ort/";
+  env.backends.onnx.wasm.wasmPaths = "ort/";
 }
 
 // `lib: ["DOM"]` types `self` as Window; give it the worker-scope shape we use.
diff --git a/tests/auth-client.test.ts b/tests/auth-client.test.ts
index 76bd902..2aba72e 100644
--- a/tests/auth-client.test.ts
+++ b/tests/auth-client.test.ts
@@ -69,7 +69,7 @@ describe("fetchAuthStatus (fail-silent /me)", () => {
     const { fetch, calls } = mockFetch(jsonResponse(200, { user: USER }));
     expect(await fetchAuthStatus(fetch)).toEqual({ enabled: true, user: USER });
     // The cookie is HttpOnly — it must ride along via same-origin credentials.
-    expect(calls[0]?.input).toBe("/api/auth/me");
+    expect(calls[0]?.input).toBe("api/auth/me");
     expect(calls[0]?.init?.credentials).toBe("same-origin");
   });
 
@@ -105,7 +105,7 @@ describe("login", () => {
     expect(await login("alice", "hunter22", fetch)).toEqual(USER);
 
     const call = calls[0];
-    expect(call?.input).toBe("/api/auth/login");
+    expect(call?.input).toBe("api/auth/login");
     expect(call?.init?.method).toBe("POST");
     expect(call?.init?.credentials).toBe("same-origin");
     expect(
@@ -145,7 +145,7 @@ describe("register", () => {
   test("returns the user on 201", async () => {
     const { fetch, calls } = mockFetch(jsonResponse(201, { user: USER }));
     expect(await register("alice", "hunter22", fetch)).toEqual(USER);
-    expect(calls[0]?.input).toBe("/api/auth/register");
+    expect(calls[0]?.input).toBe("api/auth/register");
   });
 
   test("surfaces {error} on 409 (username taken)", async () => {
@@ -172,7 +172,7 @@ describe("logout", () => {
   test("POSTs to /api/auth/logout with credentials", async () => {
     const { fetch, calls } = mockFetch(new Response(null, { status: 204 }));
     await logout(fetch);
-    expect(calls[0]?.input).toBe("/api/auth/logout");
+    expect(calls[0]?.input).toBe("api/auth/logout");
     expect(calls[0]?.init?.method).toBe("POST");
     expect(calls[0]?.init?.credentials).toBe("same-origin");
   });
diff --git a/tests/precache.test.ts b/tests/precache.test.ts
index 19e6cdc..079201a 100644
--- a/tests/precache.test.ts
+++ b/tests/precache.test.ts
@@ -11,15 +11,15 @@ describe("precachePathsFromOutputs", () => {
     expect(
       precachePathsFromOutputs(
         ["index.html", "chunk-abc123.js", "chunk-abc123.js.map", "./index-def456.css"],
-        ["/inference.worker.js"],
+        ["inference.worker.js"],
       ),
-    ).toEqual(["/", "/chunk-abc123.js", "/index-def456.css", "/inference.worker.js"]);
+    ).toEqual(["./", "chunk-abc123.js", "index-def456.css", "inference.worker.js"]);
   });
 
   test("deduplicates and sorts", () => {
-    expect(precachePathsFromOutputs(["a.js", "a.js"], ["/a.js", "/"])).toEqual([
-      "/",
-      "/a.js",
+    expect(precachePathsFromOutputs(["a.js", "a.js"], ["a.js", "./"])).toEqual([
+      "./",
+      "a.js",
     ]);
   });
 });