diff --git a/apps/laboratory/src/pages/library/multichain-siwx.tsx b/apps/laboratory/src/pages/library/multichain-siwx.tsx
index 9c9a5e53cb..6623e90b6a 100644
--- a/apps/laboratory/src/pages/library/multichain-siwx.tsx
+++ b/apps/laboratory/src/pages/library/multichain-siwx.tsx
@@ -8,7 +8,7 @@ import { AppKitButtons } from '../../components/AppKitButtons'
 import { HuobiWalletAdapter, SolflareWalletAdapter } from '@solana/wallet-adapter-wallets'
 import { MultiChainTestsEthersSolana } from '../../components/MultiChainTestsEthersSolana'
 import { mainnet } from '@reown/appkit/networks'
-import { DefaultSIWX } from '@reown/appkit-siwx'
+import { CloudAuth, DefaultSIWX } from '@reown/appkit-siwx'
 
 const networks = ConstantsUtil.AllNetworks
 
@@ -28,7 +28,9 @@ const modal = createAppKit({
   },
   termsConditionsUrl: 'https://reown.com/terms-of-service',
   privacyPolicyUrl: 'https://reown.com/privacy-policy',
-  siwx: new DefaultSIWX()
+  siwx: new DefaultSIWX({
+    storage: new CloudAuth()
+  })
 })
 
 ThemeStore.setModal(modal)
diff --git a/packages/siwx/src/storages/CloudAuth.ts b/packages/siwx/src/storages/CloudAuth.ts
new file mode 100644
index 0000000000..581df6cae9
--- /dev/null
+++ b/packages/siwx/src/storages/CloudAuth.ts
@@ -0,0 +1,101 @@
+import {
+  ApiController,
+  BlockchainApiController,
+  type SIWXMessage,
+  type SIWXSession
+} from '@reown/appkit-core'
+import type { SIWXStorage } from '../core/SIWXStorage.js'
+import { ConstantsUtil, type CaipNetworkId } from '@reown/appkit-common'
+
+export class CloudAuth implements SIWXStorage {
+  add(session: SIWXSession): Promise<void> {
+    return this.request('authenticate', {
+      message: session.message,
+      signature: session.signature,
+      clientId: BlockchainApiController.state.clientId
+    })
+  }
+
+  delete(_chainId: string, _address: string): Promise<void> {
+    return this.request('sign-out', undefined)
+  }
+
+  async get(chainId: CaipNetworkId, address: string): Promise<SIWXSession[]> {
+    try {
+      const siweSession = await this.request('me', undefined)
+      const siweCaipNetworkId = `eip155:${siweSession?.chainId}`
+
+      if (!siweSession || siweCaipNetworkId !== chainId || siweSession.address !== address) {
+        return []
+      }
+
+      const session: SIWXSession = {
+        data: {
+          accountAddress: siweSession.address,
+          chainId: siweCaipNetworkId
+        } as SIWXMessage.Data,
+        message: '',
+        signature: ''
+      }
+
+      return [session]
+    } catch {
+      return []
+    }
+  }
+
+  set(_sessions: SIWXSession[]): Promise<void> {
+    throw new Error('Set is not available for CloudAuth')
+  }
+
+  private async request<Key extends CloudAuth.RequestKey>(
+    key: Key,
+    params: CloudAuth.Requests[Key]['body']
+  ): Promise<CloudAuth.Requests[Key]['response']> {
+    const response = await fetch(`${ConstantsUtil.W3M_API_URL}/auth/v1/${key}`, {
+      method: RequestMethod[key],
+      body: JSON.stringify(params),
+      headers: ApiController._getApiHeaders() satisfies { 'x-project-id': string }
+    })
+
+    if (response.headers.get('content-type')?.includes('application/json')) {
+      return response.json()
+    }
+
+    throw new Error(await response.text())
+  }
+}
+
+const RequestMethod = {
+  nonce: 'GET',
+  me: 'GET',
+  authenticate: 'POST',
+  'update-user-metadata': 'PATCH',
+  'sign-out': 'POST'
+} satisfies { [key in CloudAuth.RequestKey]: CloudAuth.Requests[key]['method'] }
+
+export namespace CloudAuth {
+  export type Request<Method extends 'GET' | 'POST' | 'PATCH', Params, Response> = {
+    method: Method
+    body: Params
+    response: Response
+  }
+
+  export type Requests = {
+    nonce: Request<'GET', undefined, { nonce: string }>
+    me: Request<'GET', undefined, { address: string; chainId: string }>
+    authenticate: Request<
+      'POST',
+      {
+        message: string
+        signature: string
+        clientId?: string | null
+      },
+      never
+    >
+    'update-user-metadata': Request<'PATCH', Record<string, unknown>, unknown>
+    'sign-out': Request<'POST', undefined, never>
+  }
+
+  export type RequestKey = keyof Requests
+}
diff --git a/packages/siwx/src/storages/index.ts b/packages/siwx/src/storages/index.ts
index 9af82f0252..893e6dd407 100644
--- a/packages/siwx/src/storages/index.ts
+++ b/packages/siwx/src/storages/index.ts
@@ -1 +1,2 @@
 export * from './LocalStorage.js'
+export * from './CloudAuth.js'