diff --git a/mobile/package.json b/mobile/package.json
index 85eb4f2..caefd6b 100644
--- a/mobile/package.json
+++ b/mobile/package.json
@@ -17,6 +17,7 @@
   "dependencies": {
     "@bytelyst/api-client": "*",
     "@bytelyst/auth-client": "*",
+    "@bytelyst/billing-client": "*",
     "@bytelyst/blob-client": "*",
     "@bytelyst/broadcast-client": "*",
     "@bytelyst/design-tokens": "*",
@@ -25,6 +26,7 @@
     "@bytelyst/feedback-client": "*",
     "@bytelyst/kill-switch-client": "*",
     "@bytelyst/offline-queue": "*",
+    "@bytelyst/platform-client": "*",
     "@bytelyst/survey-client": "*",
     "@bytelyst/telemetry-client": "*",
     "expo": "~55.0.4",
diff --git a/mobile/src/lib/billing-client.ts b/mobile/src/lib/billing-client.ts
new file mode 100644
index 0000000..3755a9c
--- /dev/null
+++ b/mobile/src/lib/billing-client.ts
@@ -0,0 +1,20 @@
+import { createBillingClient, type BillingClient } from '@bytelyst/billing-client';
+import { API_CONFIG, PRODUCT_ID } from '../api/config';
+import { mmkvStorage } from '../store/mmkv-storage';
+
+function getAccessToken(): string | null {
+  return mmkvStorage.getItem(`${PRODUCT_ID}_access_token`);
+}
+
+let _client: BillingClient | null = null;
+
+export function getBillingClient(): BillingClient {
+  if (!_client) {
+    _client = createBillingClient({
+      baseUrl: API_CONFIG.platformBaseUrl,
+      productId: PRODUCT_ID,
+      getAccessToken,
+    });
+  }
+  return _client;
+}
diff --git a/mobile/src/lib/platform-api.ts b/mobile/src/lib/platform-api.ts
new file mode 100644
index 0000000..cb2379d
--- /dev/null
+++ b/mobile/src/lib/platform-api.ts
@@ -0,0 +1,54 @@
+import { createPlatformClient, type PlatformClient } from '@bytelyst/platform-client';
+import { API_CONFIG, PRODUCT_ID } from '../api/config';
+import { mmkvStorage } from '../store/mmkv-storage';
+
+function getAccessToken(): string | null {
+  return mmkvStorage.getItem(`${PRODUCT_ID}_access_token`);
+}
+
+let _client: PlatformClient | null = null;
+
+function getClient(): PlatformClient {
+  if (!_client) {
+    _client = createPlatformClient({
+      baseUrl: API_CONFIG.platformBaseUrl,
+      productId: PRODUCT_ID,
+      getAccessToken,
+    });
+  }
+  return _client;
+}
+
+export interface UserSettings {
+  theme?: 'dark' | 'light' | 'system';
+  language?: string;
+  notificationsEnabled?: boolean;
+  [key: string]: unknown;
+}
+
+export interface ActiveSession {
+  id: string;
+  deviceName: string;
+  lastActiveAt: string;
+  isCurrent: boolean;
+}
+
+export async function getUserSettings(): Promise<UserSettings> {
+  return getClient().get<UserSettings>('/settings');
+}
+
+export async function updateUserSettings(settings: Partial<UserSettings>): Promise<UserSettings> {
+  return getClient().put<UserSettings>('/settings', settings);
+}
+
+export async function listSessions(): Promise<ActiveSession[]> {
+  return getClient().get<ActiveSession[]>('/sessions');
+}
+
+export async function revokeSession(sessionId: string): Promise<void> {
+  await getClient().del(`/sessions/${sessionId}`);
+}
+
+export async function updateProfile(updates: { displayName?: string }): Promise<void> {
+  await getClient().put('/auth/profile', updates);
+}
diff --git a/web/package.json b/web/package.json
index da3d284..0fab40c 100644
--- a/web/package.json
+++ b/web/package.json
@@ -15,6 +15,7 @@
   },
   "dependencies": {
     "@bytelyst/api-client": "*",
+    "@bytelyst/billing-client": "*",
     "@bytelyst/design-tokens": "*",
     "@bytelyst/blob-client": "*",
     "@bytelyst/diagnostics-client": "*",
diff --git a/web/src/lib/billing-client.ts b/web/src/lib/billing-client.ts
new file mode 100644
index 0000000..8b78634
--- /dev/null
+++ b/web/src/lib/billing-client.ts
@@ -0,0 +1,18 @@
+"use client";
+
+import { createBillingClient, type BillingClient } from "@bytelyst/billing-client";
+import { PLATFORM_SERVICE_URL, PRODUCT_ID } from "@/lib/product-config";
+import { getAccessToken } from "@/lib/api-helpers";
+
+let _client: BillingClient | null = null;
+
+export function getBillingClient(): BillingClient {
+  if (!_client) {
+    _client = createBillingClient({
+      baseUrl: PLATFORM_SERVICE_URL,
+      productId: PRODUCT_ID,
+      getAccessToken,
+    });
+  }
+  return _client;
+}