diff --git a/DysonNetwork.Sphere/Wallet/SubscriptionController.cs b/DysonNetwork.Sphere/Wallet/SubscriptionController.cs
index da55eff..3dbc0d2 100644
--- a/DysonNetwork.Sphere/Wallet/SubscriptionController.cs
+++ b/DysonNetwork.Sphere/Wallet/SubscriptionController.cs
@@ -136,7 +136,7 @@ public class SubscriptionController(SubscriptionService subscriptions, AppDataba
 
     public class SubscriptionOrderRequest
     {
-        [Required] public string OrderId { get; set; } = null!;
+        [Required] public Guid OrderId { get; set; }
     }
 
     [HttpPost("order/handle")]
diff --git a/DysonNetwork.Sphere/Wallet/SubscriptionService.cs b/DysonNetwork.Sphere/Wallet/SubscriptionService.cs
index 2e0b19c..8f73fa2 100644
--- a/DysonNetwork.Sphere/Wallet/SubscriptionService.cs
+++ b/DysonNetwork.Sphere/Wallet/SubscriptionService.cs
@@ -1,3 +1,4 @@
+using System.Text.Json;
 using DysonNetwork.Sphere.Storage;
 using Microsoft.EntityFrameworkCore;
 using NodaTime;
@@ -139,16 +140,16 @@ public class SubscriptionService(AppDatabase db, PaymentService payment, ICacheS
     public async Task<Subscription> HandleSubscriptionOrder(Order order)
     {
         if (order.AppIdentifier != SubscriptionOrderIdentifier || order.Status != OrderStatus.Paid ||
-            order.Meta?["subscription_id"] is not string subscriptionId)
+            order.Meta?["subscription_id"] is not JsonElement subscriptionIdJson)
             throw new InvalidOperationException("Invalid order.");
 
-        var subscriptionIdParsed = Guid.TryParse(subscriptionId, out var parsedSubscriptionId)
+        var subscriptionId = Guid.TryParse(subscriptionIdJson.ToString(), out var parsedSubscriptionId)
             ? parsedSubscriptionId
             : Guid.Empty;
-        if (subscriptionIdParsed == Guid.Empty)
+        if (subscriptionId == Guid.Empty)
             throw new InvalidOperationException("Invalid order.");
         var subscription = await db.WalletSubscriptions
-            .Where(s => s.Id == subscriptionIdParsed)
+            .Where(s => s.Id == subscriptionId)
             .Include(s => s.Coupon)
             .FirstOrDefaultAsync();
         if (subscription is null)
diff --git a/DysonNetwork.Sphere/Wallet/WalletController.cs b/DysonNetwork.Sphere/Wallet/WalletController.cs
index 1e59d28..92d9208 100644
--- a/DysonNetwork.Sphere/Wallet/WalletController.cs
+++ b/DysonNetwork.Sphere/Wallet/WalletController.cs
@@ -1,3 +1,5 @@
+using System.ComponentModel.DataAnnotations;
+using DysonNetwork.Sphere.Permission;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -6,7 +8,7 @@ namespace DysonNetwork.Sphere.Wallet;
 
 [ApiController]
 [Route("/wallets")]
-public class WalletController(AppDatabase db, WalletService ws) : ControllerBase
+public class WalletController(AppDatabase db, WalletService ws, PaymentService payment) : ControllerBase
 {
     [HttpPost]
     [Authorize]
@@ -61,4 +63,39 @@ public class WalletController(AppDatabase db, WalletService ws) : ControllerBase
 
         return Ok(transactions);
     }
+
+    public class WalletBalanceRequest
+    {
+        public string? Remark { get; set; }
+        [Required] public decimal Amount { get; set; }
+        [Required] public string Currency { get; set; } = null!;
+        [Required] public Guid AccountId { get; set; }
+    }
+
+    [HttpPost("balance")]
+    [Authorize]
+    [RequiredPermission("maintenance", "wallets.balance.modify")]
+    public async Task<ActionResult<Transaction>> ModifyWalletBalance([FromBody] WalletBalanceRequest request)
+    {
+        var wallet = await ws.GetWalletAsync(request.AccountId);
+        if (wallet is null) return NotFound("Wallet was not found.");
+
+        var transaction = request.Amount >= 0
+            ? await payment.CreateTransactionAsync(
+                payerWalletId: null,
+                payeeWalletId: wallet.Id,
+                currency: request.Currency,
+                amount: request.Amount,
+                remarks: request.Remark
+            )
+            : await payment.CreateTransactionAsync(
+                payerWalletId: wallet.Id,
+                payeeWalletId: null,
+                currency: request.Currency,
+                amount: request.Amount,
+                remarks: request.Remark
+            );
+
+        return Ok(transaction);
+    }
 }
\ No newline at end of file