diff --git a/clients/chrome-extension/background/worker.ts b/clients/chrome-extension/background/worker.ts
index d48469791b7..a89774ac32d 100644
--- a/clients/chrome-extension/background/worker.ts
+++ b/clients/chrome-extension/background/worker.ts
@@ -256,7 +256,7 @@ function missingTokenMessage(kind: RelayModeKind): string {
   if (kind === 'cloud') {
     return 'Sign in with Vellum (cloud) before connecting';
   }
-  return 'Pair the Vellum daemon (self-hosted) before connecting';
+  return 'Pair the Vellum assistant (self-hosted) before connecting';
 }
 
 async function connect(): Promise<void> {
diff --git a/clients/chrome-extension/tsconfig.json b/clients/chrome-extension/tsconfig.json
index 7476c828e31..300f3cb23e7 100644
--- a/clients/chrome-extension/tsconfig.json
+++ b/clients/chrome-extension/tsconfig.json
@@ -15,12 +15,9 @@
     "types": []
   },
   "include": [
-    "background/cdp-proxy.ts",
-    "background/cloud-auth.ts",
-    "background/host-browser-dispatcher.ts",
-    "background/relay-connection.ts",
-    "background/self-hosted-auth.ts",
-    "background/__tests__/**/*.ts",
+    "background/**/*.ts",
+    "popup/**/*.ts",
     "types/**/*.d.ts"
-  ]
+  ],
+  "exclude": ["dist/**", "node_modules/**"]
 }
diff --git a/clients/chrome-extension/types/chrome-globals.d.ts b/clients/chrome-extension/types/chrome-globals.d.ts
index 426b4edfdaa..20e4cdeed0b 100644
--- a/clients/chrome-extension/types/chrome-globals.d.ts
+++ b/clients/chrome-extension/types/chrome-globals.d.ts
@@ -4,58 +4,244 @@
  * Minimal ambient declarations for the subset of the Chrome Extension API
  * surface used by the Vellum browser-relay extension's typed modules.
  *
- * This is intentionally narrow — it covers what's needed by
- * background/cloud-auth.ts, background/self-hosted-auth.ts, and their tests.
- * The full @types/chrome package is an option for the future if we type-check
- * more of the package.
+ * This is intentionally narrow — it covers what's needed by the
+ * typechecked files under `background/` and `popup/`, not the full
+ * Chrome API surface. The full `@types/chrome` package is an option for
+ * the future if we type-check more of the package or need additional
+ * API surface that this file doesn't cover.
+ *
+ * Note: `debugger` is a reserved word in TypeScript so we cannot declare
+ * a `namespace chrome.debugger`. Instead, `chrome` is declared as a
+ * top-level `const` whose type is an interface — that shape can include
+ * a `debugger` property because object literal property names may use
+ * reserved words.
  */
 
-declare namespace chrome {
-  namespace storage {
-    interface StorageArea {
-      get(keys?: string | string[] | Record<string, unknown> | null): Promise<Record<string, unknown>>;
-      set(items: Record<string, unknown>): Promise<void>;
-      remove(keys: string | string[]): Promise<void>;
-      clear(): Promise<void>;
-    }
-    const local: StorageArea;
-    const sync: StorageArea;
-    const session: StorageArea;
-  }
-
-  namespace identity {
-    interface WebAuthFlowDetails {
-      url: string;
-      interactive?: boolean;
-    }
-    function getRedirectURL(path?: string): string;
-    function launchWebAuthFlow(details: WebAuthFlowDetails): Promise<string | undefined>;
-  }
-
-  namespace runtime {
-    interface LastError {
-      message?: string;
-    }
-    const lastError: LastError | undefined;
-
-    interface PortMessageEvent {
-      addListener(listener: (message: unknown) => void): void;
-      removeListener(listener: (message: unknown) => void): void;
-    }
-
-    interface PortDisconnectEvent {
-      addListener(listener: (port: Port) => void): void;
-      removeListener(listener: (port: Port) => void): void;
-    }
-
-    interface Port {
-      name: string;
-      onMessage: PortMessageEvent;
-      onDisconnect: PortDisconnectEvent;
-      postMessage(message: unknown): void;
-      disconnect(): void;
-    }
-
-    function connectNative(application: string): Port;
-  }
+interface ChromeStorageArea {
+  get(keys?: string | string[] | Record<string, unknown> | null): Promise<Record<string, unknown>>;
+  set(items: Record<string, unknown>): Promise<void>;
+  remove(keys: string | string[]): Promise<void>;
+  clear(): Promise<void>;
+}
+
+interface ChromeStorageChange {
+  newValue?: unknown;
+  oldValue?: unknown;
+}
+
+type ChromeStorageAreaName = 'local' | 'sync' | 'managed' | 'session';
+
+interface ChromeStorageChangedEvent {
+  addListener(
+    listener: (
+      changes: Record<string, ChromeStorageChange>,
+      areaName: ChromeStorageAreaName,
+    ) => void,
+  ): void;
+  removeListener(
+    listener: (
+      changes: Record<string, ChromeStorageChange>,
+      areaName: ChromeStorageAreaName,
+    ) => void,
+  ): void;
+}
+
+interface ChromeStorageNamespace {
+  local: ChromeStorageArea;
+  sync: ChromeStorageArea;
+  session: ChromeStorageArea;
+  onChanged: ChromeStorageChangedEvent;
+}
+
+interface ChromeIdentityWebAuthFlowDetails {
+  url: string;
+  interactive?: boolean;
+}
+
+interface ChromeIdentityNamespace {
+  getRedirectURL(path?: string): string;
+  launchWebAuthFlow(details: ChromeIdentityWebAuthFlowDetails): Promise<string | undefined>;
+}
+
+interface ChromeRuntimeLastError {
+  message?: string;
+}
+
+interface ChromeRuntimePortMessageEvent {
+  addListener(listener: (message: unknown) => void): void;
+  removeListener(listener: (message: unknown) => void): void;
+}
+
+interface ChromeRuntimePortDisconnectEvent {
+  addListener(listener: (port: ChromeRuntimePort) => void): void;
+  removeListener(listener: (port: ChromeRuntimePort) => void): void;
+}
+
+interface ChromeRuntimePort {
+  name: string;
+  onMessage: ChromeRuntimePortMessageEvent;
+  onDisconnect: ChromeRuntimePortDisconnectEvent;
+  postMessage(message: unknown): void;
+  disconnect(): void;
+}
+
+interface ChromeRuntimeMessageSender {
+  tab?: ChromeTab;
+  frameId?: number;
+  id?: string;
+  url?: string;
+  tlsChannelId?: string;
+  origin?: string;
+}
+
+type ChromeRuntimeMessageListener = (
+  message: Record<string, unknown> & { type?: string },
+  sender: ChromeRuntimeMessageSender,
+  sendResponse: (response?: unknown) => void,
+) => boolean | void;
+
+interface ChromeRuntimeOnMessageEvent {
+  addListener(listener: ChromeRuntimeMessageListener): void;
+  removeListener(listener: ChromeRuntimeMessageListener): void;
+}
+
+interface ChromeRuntimeManifest {
+  version: string;
+  [key: string]: unknown;
+}
+
+interface ChromeRuntimeNamespace {
+  readonly lastError: ChromeRuntimeLastError | undefined;
+  connectNative(application: string): ChromeRuntimePort;
+  onMessage: ChromeRuntimeOnMessageEvent;
+  // Generic over the response type so callers can narrow the callback
+  // argument without casting. Matches the de-facto shape used by the
+  // official @types/chrome package.
+  sendMessage<TResponse = unknown>(
+    message: unknown,
+    responseCallback?: (response: TResponse) => void,
+  ): void;
+  getManifest(): ChromeRuntimeManifest;
 }
+
+interface ChromeTab {
+  id?: number;
+  windowId?: number;
+  url?: string;
+  active?: boolean;
+  title?: string;
+  index?: number;
+}
+
+interface ChromeTabsQueryInfo {
+  active?: boolean;
+  lastFocusedWindow?: boolean;
+  url?: string | string[];
+  windowId?: number;
+  currentWindow?: boolean;
+  [key: string]: unknown;
+}
+
+interface ChromeTabsCreateProperties {
+  url?: string;
+  active?: boolean;
+  windowId?: number;
+  index?: number;
+}
+
+interface ChromeTabsUpdateProperties {
+  url?: string;
+  active?: boolean;
+  [key: string]: unknown;
+}
+
+interface ChromeTabsCaptureVisibleTabOptions {
+  format?: 'jpeg' | 'png';
+  quality?: number;
+}
+
+interface ChromeTabsNamespace {
+  query(queryInfo: ChromeTabsQueryInfo): Promise<ChromeTab[]>;
+  get(tabId: number): Promise<ChromeTab>;
+  create(createProperties: ChromeTabsCreateProperties): Promise<ChromeTab>;
+  update(tabId: number, updateProperties: ChromeTabsUpdateProperties): Promise<ChromeTab | undefined>;
+  captureVisibleTab(
+    windowId: number,
+    options?: ChromeTabsCaptureVisibleTabOptions,
+  ): Promise<string>;
+}
+
+interface ChromeWindowsNamespace {
+  readonly WINDOW_ID_CURRENT: number;
+  readonly WINDOW_ID_NONE: number;
+}
+
+interface ChromeCookie {
+  name: string;
+  value: string;
+  domain: string;
+  hostOnly?: boolean;
+  path: string;
+  secure: boolean;
+  httpOnly: boolean;
+  sameSite?: 'no_restriction' | 'lax' | 'strict' | 'unspecified';
+  session?: boolean;
+  expirationDate?: number;
+  storeId?: string;
+}
+
+interface ChromeCookiesGetAllDetails {
+  domain?: string;
+  name?: string;
+  path?: string;
+  secure?: boolean;
+  session?: boolean;
+  storeId?: string;
+  url?: string;
+}
+
+interface ChromeCookiesSetDetails {
+  url: string;
+  name?: string;
+  value?: string;
+  domain?: string;
+  path?: string;
+  secure?: boolean;
+  httpOnly?: boolean;
+  sameSite?: 'no_restriction' | 'lax' | 'strict' | 'unspecified';
+  expirationDate?: number;
+  storeId?: string;
+}
+
+interface ChromeCookiesNamespace {
+  getAll(details: ChromeCookiesGetAllDetails): Promise<ChromeCookie[]>;
+  set(details: ChromeCookiesSetDetails): Promise<ChromeCookie | null>;
+}
+
+interface ChromeDebuggerDebuggee {
+  tabId?: number;
+  extensionId?: string;
+  targetId?: string;
+}
+
+interface ChromeDebuggerNamespace {
+  attach(target: ChromeDebuggerDebuggee, requiredVersion: string): Promise<void>;
+  detach(target: ChromeDebuggerDebuggee): Promise<void>;
+  sendCommand(
+    target: ChromeDebuggerDebuggee,
+    method: string,
+    commandParams?: Record<string, unknown>,
+  ): Promise<unknown>;
+}
+
+interface ChromeGlobal {
+  storage: ChromeStorageNamespace;
+  identity: ChromeIdentityNamespace;
+  runtime: ChromeRuntimeNamespace;
+  tabs: ChromeTabsNamespace;
+  windows: ChromeWindowsNamespace;
+  cookies: ChromeCookiesNamespace;
+  debugger: ChromeDebuggerNamespace;
+}
+
+declare const chrome: ChromeGlobal;