diff --git a/Tiku.Api/Contracts/CommerceDtos.cs b/Tiku.Api/Contracts/CommerceDtos.cs
new file mode 100644
index 0000000..07aa865
--- /dev/null
+++ b/Tiku.Api/Contracts/CommerceDtos.cs
@@ -0,0 +1,79 @@
+using System.ComponentModel.DataAnnotations;
+using Tiku.Application.Commerce;
+
+namespace Tiku.Api.Contracts;
+
+public sealed class CreateCommerceOrderDto
+{
+    [Required]
+    public Guid PlanId { get; set; }
+
+    [Range(1, 99)]
+    public int Quantity { get; set; } = 1;
+
+    [StringLength(50)]
+    public string? PayMethod { get; set; }
+
+    [StringLength(50)]
+    public string? PayProvider { get; set; }
+
+    public Guid? RegionId { get; set; }
+
+    [StringLength(100)]
+    public string? CouponCode { get; set; }
+
+    public CreateCommerceOrderCommand ToCommand()
+    {
+        return new CreateCommerceOrderCommand(
+            PlanId,
+            Quantity,
+            PayMethod,
+            PayProvider,
+            RegionId,
+            CouponCode);
+    }
+}
+
+public sealed class CommerceOrderQueryDto
+{
+    [Range(1, 100)]
+    public int? Limit { get; set; }
+
+    [StringLength(32)]
+    public string? Status { get; set; }
+}
+
+public sealed class CreateCommercePaymentDto
+{
+    [Required]
+    [StringLength(100)]
+    public string OrderNo { get; set; } = string.Empty;
+
+    [Required]
+    [StringLength(50)]
+    public string Provider { get; set; } = string.Empty;
+
+    [Required]
+    [StringLength(50)]
+    public string Method { get; set; } = string.Empty;
+
+    [StringLength(255)]
+    public string? OpenId { get; set; }
+
+    [StringLength(2048)]
+    public string? ReturnUrl { get; set; }
+
+    [StringLength(2048)]
+    public string? QuitUrl { get; set; }
+
+    public CreateCommercePaymentCommand ToCommand()
+    {
+        return new CreateCommercePaymentCommand(
+            OrderNo,
+            Provider,
+            Method,
+            OpenId,
+            ReturnUrl,
+            QuitUrl);
+    }
+}
diff --git a/Tiku.Api/Controllers/CommerceController.cs b/Tiku.Api/Controllers/CommerceController.cs
new file mode 100644
index 0000000..bc178bf
--- /dev/null
+++ b/Tiku.Api/Controllers/CommerceController.cs
@@ -0,0 +1,90 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Tiku.Api.Contracts;
+using Tiku.Application.Commerce;
+using Tiku.Application.Security;
+
+namespace Tiku.Api.Controllers;
+
+[ApiController]
+[Authorize(Policy = TikuPolicies.CurrentTenantMember)]
+[Produces("application/json")]
+[Route("api/commerce")]
+public sealed class CommerceController(
+    ICommerceService commerceService,
+    ICurrentUser currentUser,
+    ICurrentTenant currentTenant) : ControllerBase
+{
+    [HttpPost("orders")]
+    [EndpointSummary("创建学生端订单")]
+    [ProducesResponseType<CommerceOrderItem>(StatusCodes.Status200OK)]
+    public async Task<ActionResult<CommerceOrderItem>> CreateOrder(
+        CreateCommerceOrderDto request,
+        CancellationToken cancellationToken)
+    {
+        return Ok(await commerceService.CreateOrderAsync(
+            ResolveActor(),
+            request.ToCommand(),
+            cancellationToken));
+    }
+
+    [HttpGet("orders")]
+    [EndpointSummary("查询当前用户订单")]
+    [ProducesResponseType<CommerceOrderList>(StatusCodes.Status200OK)]
+    public async Task<ActionResult<CommerceOrderList>> Orders(
+        [FromQuery] CommerceOrderQueryDto query,
+        CancellationToken cancellationToken)
+    {
+        return Ok(await commerceService.GetOrdersAsync(
+            ResolveActor(),
+            new CommerceOrderQuery(query.Limit, query.Status),
+            cancellationToken));
+    }
+
+    [HttpGet("orders/{orderNo}")]
+    [EndpointSummary("查询当前用户订单详情")]
+    [ProducesResponseType<CommerceOrderItem>(StatusCodes.Status200OK)]
+    public async Task<ActionResult<CommerceOrderItem>> Order(
+        string orderNo,
+        CancellationToken cancellationToken)
+    {
+        return Ok(await commerceService.GetOrderAsync(
+            ResolveActor(),
+            orderNo,
+            cancellationToken));
+    }
+
+    [HttpPost("payments")]
+    [EndpointSummary("创建订单支付")]
+    [ProducesResponseType<CommercePaymentItem>(StatusCodes.Status200OK)]
+    public async Task<ActionResult<CommercePaymentItem>> CreatePayment(
+        CreateCommercePaymentDto request,
+        CancellationToken cancellationToken)
+    {
+        return Ok(await commerceService.CreatePaymentAsync(
+            ResolveActor(),
+            request.ToCommand(),
+            cancellationToken));
+    }
+
+    [HttpGet("entitlements/current")]
+    [EndpointSummary("查询当前用户权益")]
+    [ProducesResponseType<CurrentEntitlementItem>(StatusCodes.Status200OK)]
+    public async Task<ActionResult<CurrentEntitlementItem>> CurrentEntitlement(
+        CancellationToken cancellationToken)
+    {
+        return Ok(await commerceService.GetCurrentEntitlementAsync(
+            ResolveActor(),
+            cancellationToken));
+    }
+
+    private CommerceActor ResolveActor()
+    {
+        if (currentTenant.TenantId is null || currentUser.UserId is null)
+        {
+            throw new CommerceException("Current commerce actor was not resolved.", "commerce_access_denied");
+        }
+
+        return new CommerceActor(currentTenant.TenantId.Value, currentUser.UserId.Value);
+    }
+}
diff --git a/Tiku.Api/Middleware/ExceptionHandlingMiddleware.cs b/Tiku.Api/Middleware/ExceptionHandlingMiddleware.cs
index 865197d..9d30b76 100644
--- a/Tiku.Api/Middleware/ExceptionHandlingMiddleware.cs
+++ b/Tiku.Api/Middleware/ExceptionHandlingMiddleware.cs
@@ -2,6 +2,7 @@ using Microsoft.AspNetCore.Mvc;
 using Tiku.Api.Controllers;
 using Tiku.Application.Assets;
 using Tiku.Application.Auth;
+using Tiku.Application.Commerce;
 using Tiku.Application.Content;
 using Tiku.Application.Storage;
 using Tiku.Infrastructure.Content;
@@ -172,6 +173,26 @@ public sealed class ExceptionHandlingMiddleware(
                 return;
             }
 
+            if (exception is CommerceException commerceException)
+            {
+                await WriteProblemAsync(
+                    context,
+                    commerceException.Message,
+                    CommerceStatusCode(commerceException.Code),
+                    commerceException.Code);
+                return;
+            }
+
+            if (exception is PaymentProviderException paymentProviderException)
+            {
+                await WriteProblemAsync(
+                    context,
+                    paymentProviderException.Message,
+                    CommerceStatusCode(paymentProviderException.Code),
+                    paymentProviderException.Code);
+                return;
+            }
+
             if (exception is ObjectStorageException storageException)
             {
                 await WriteProblemAsync(
@@ -308,4 +329,16 @@ public sealed class ExceptionHandlingMiddleware(
             _ => StatusCodes.Status400BadRequest
         };
     }
+
+    private static int CommerceStatusCode(string code)
+    {
+        return code switch
+        {
+            "commerce_access_denied" or "tenant_access_denied" => StatusCodes.Status403Forbidden,
+            "order_not_found" or "svip_plan_not_found" or "region_not_found" => StatusCodes.Status404NotFound,
+            "payment_provider_not_configured" or "payment_secret_not_configured" => StatusCodes.Status503ServiceUnavailable,
+            "order_status_invalid" => StatusCodes.Status409Conflict,
+            _ => StatusCodes.Status400BadRequest
+        };
+    }
 }
diff --git a/Tiku.Application/Commerce/CommerceModels.cs b/Tiku.Application/Commerce/CommerceModels.cs
new file mode 100644
index 0000000..7a11563
--- /dev/null
+++ b/Tiku.Application/Commerce/CommerceModels.cs
@@ -0,0 +1,97 @@
+using System.Text.Json;
+
+namespace Tiku.Application.Commerce;
+
+public sealed record CommerceActor(Guid TenantId, Guid UserId);
+
+public sealed record CreateCommerceOrderCommand(
+    Guid PlanId,
+    int Quantity,
+    string? PayMethod,
+    string? PayProvider,
+    Guid? RegionId,
+    string? CouponCode);
+
+public sealed record CommerceOrderQuery(int? Limit = null, string? Status = null);
+
+public sealed record CreateCommercePaymentCommand(
+    string OrderNo,
+    string Provider,
+    string Method,
+    string? OpenId,
+    string? ReturnUrl,
+    string? QuitUrl);
+
+public sealed record CommerceOrderItem(
+    Guid Id,
+    string OrderNo,
+    string Status,
+    Guid? PlanId,
+    Guid? RegionId,
+    string? ProductType,
+    string? ProductName,
+    int AmountCents,
+    string Price,
+    string? PayMethod,
+    string? PayProvider,
+    string? TradeNo,
+    int? Days,
+    DateTimeOffset? PaidAt,
+    DateTimeOffset CreatedAt,
+    JsonElement RawPayload);
+
+public sealed record CommerceOrderList(IReadOnlyCollection<CommerceOrderItem> Items);
+
+public sealed record CommercePaymentItem(
+    Guid Id,
+    Guid OrderId,
+    string OrderNo,
+    string Provider,
+    string? Method,
+    string Status,
+    int AmountCents,
+    string Price,
+    string? ProviderTradeNo,
+    DateTimeOffset? PaidAt,
+    JsonElement ClientPayload,
+    JsonElement RawPayload);
+
+public sealed record CurrentEntitlementItem(
+    bool IsActive,
+    string EntitlementType,
+    DateTimeOffset? StartsAt,
+    DateTimeOffset? ExpiresAt,
+    string Status,
+    int? DaysLeft);
+
+public interface ICommerceService
+{
+    Task<CommerceOrderItem> CreateOrderAsync(
+        CommerceActor actor,
+        CreateCommerceOrderCommand command,
+        CancellationToken cancellationToken = default);
+
+    Task<CommerceOrderList> GetOrdersAsync(
+        CommerceActor actor,
+        CommerceOrderQuery query,
+        CancellationToken cancellationToken = default);
+
+    Task<CommerceOrderItem> GetOrderAsync(
+        CommerceActor actor,
+        string orderNo,
+        CancellationToken cancellationToken = default);
+
+    Task<CommercePaymentItem> CreatePaymentAsync(
+        CommerceActor actor,
+        CreateCommercePaymentCommand command,
+        CancellationToken cancellationToken = default);
+
+    Task<CurrentEntitlementItem> GetCurrentEntitlementAsync(
+        CommerceActor actor,
+        CancellationToken cancellationToken = default);
+}
+
+public sealed class CommerceException(string message, string code) : Exception(message)
+{
+    public string Code { get; } = code;
+}
diff --git a/Tiku.Infrastructure/Commerce/CommerceService.cs b/Tiku.Infrastructure/Commerce/CommerceService.cs
new file mode 100644
index 0000000..e99ce93
--- /dev/null
+++ b/Tiku.Infrastructure/Commerce/CommerceService.cs
@@ -0,0 +1,419 @@
+using System.Globalization;
+using System.Security.Cryptography;
+using System.Text.Json;
+using Microsoft.EntityFrameworkCore;
+using Tiku.Application.Commerce;
+using Tiku.Domain.Commerce;
+using Tiku.Domain.Common;
+using Tiku.Domain.Tenancy;
+using Tiku.Infrastructure.Persistence;
+
+namespace Tiku.Infrastructure.Commerce;
+
+public sealed class CommerceService(
+    TikuDbContext dbContext,
+    IPaymentProviderGateway paymentGateway) : ICommerceService
+{
+    public async Task<CommerceOrderItem> CreateOrderAsync(
+        CommerceActor actor,
+        CreateCommerceOrderCommand command,
+        CancellationToken cancellationToken = default)
+    {
+        if (command.Quantity is < 1 or > 99)
+        {
+            throw new CommerceException("Quantity must be between 1 and 99.", "invalid_quantity");
+        }
+
+        await AssertActiveMemberAsync(actor, cancellationToken);
+        var plan = await dbContext.SvipPlans
+            .AsNoTracking()
+            .SingleOrDefaultAsync(item =>
+                item.TenantId == actor.TenantId &&
+                item.Id == command.PlanId &&
+                item.IsActive,
+                cancellationToken)
+            ?? throw new CommerceException("SVIP plan was not found.", "svip_plan_not_found");
+
+        if (plan.CouponOnly && string.IsNullOrWhiteSpace(command.CouponCode))
+        {
+            throw new CommerceException("This SVIP plan requires a coupon.", "coupon_required");
+        }
+
+        if (command.RegionId.HasValue)
+        {
+            var regionExists = await dbContext.Regions
+                .AnyAsync(item => item.TenantId == actor.TenantId && item.Id == command.RegionId.Value, cancellationToken);
+            if (!regionExists)
+            {
+                throw new CommerceException("Region was not found.", "region_not_found");
+            }
+        }
+
+        var order = new Order
+        {
+            TenantId = actor.TenantId,
+            UserId = actor.UserId,
+            PlanId = plan.Id,
+            RegionId = command.RegionId ?? plan.RegionId,
+            OrderNo = GenerateOrderNo(),
+            Status = OrderStatus.Pending,
+            ProductType = "svip",
+            ProductName = plan.Name,
+            AmountCents = checked(plan.PriceCents * command.Quantity),
+            PayMethod = NormalizeMethod(command.PayMethod),
+            PayProvider = NormalizeProvider(command.PayProvider),
+            Days = checked(plan.Days * command.Quantity),
+            RawPayload = JsonSerializer.SerializeToElement(new
+            {
+                source = "student_checkout",
+                command.Quantity,
+                command.CouponCode,
+                plan.PriceCents,
+                plan.OriginalPriceCents
+            })
+        };
+        dbContext.Orders.Add(order);
+        dbContext.OrderItems.Add(new OrderItem
+        {
+            TenantId = actor.TenantId,
+            OrderId = order.Id,
+            ItemType = "svip_plan",
+            ItemId = plan.Id,
+            Name = plan.Name,
+            Quantity = command.Quantity,
+            UnitAmountCents = plan.PriceCents,
+            TotalAmountCents = order.AmountCents,
+            Metadata = JsonSerializer.SerializeToElement(new
+            {
+                plan.Days,
+                plan.RegionId,
+                plan.VpProductId
+            })
+        });
+
+        await dbContext.SaveChangesAsync(cancellationToken);
+        return ToOrderItem(order);
+    }
+
+    public async Task<CommerceOrderList> GetOrdersAsync(
+        CommerceActor actor,
+        CommerceOrderQuery query,
+        CancellationToken cancellationToken = default)
+    {
+        await AssertActiveMemberAsync(actor, cancellationToken);
+        var orders = dbContext.Orders.AsNoTracking()
+            .Where(item => item.TenantId == actor.TenantId && item.UserId == actor.UserId);
+        if (!string.IsNullOrWhiteSpace(query.Status))
+        {
+            orders = orders.Where(item => item.Status == ParseOrderStatus(query.Status));
+        }
+
+        var items = await orders
+            .OrderByDescending(item => item.CreatedAt)
+            .Take(Math.Clamp(query.Limit ?? 20, 1, 100))
+            .ToArrayAsync(cancellationToken);
+
+        return new CommerceOrderList(items.Select(ToOrderItem).ToArray());
+    }
+
+    public async Task<CommerceOrderItem> GetOrderAsync(
+        CommerceActor actor,
+        string orderNo,
+        CancellationToken cancellationToken = default)
+    {
+        await AssertActiveMemberAsync(actor, cancellationToken);
+        var order = await FindActorOrderAsync(actor, orderNo, cancellationToken);
+        return ToOrderItem(order);
+    }
+
+    public async Task<CommercePaymentItem> CreatePaymentAsync(
+        CommerceActor actor,
+        CreateCommercePaymentCommand command,
+        CancellationToken cancellationToken = default)
+    {
+        await AssertActiveMemberAsync(actor, cancellationToken);
+        var order = await FindActorOrderAsync(actor, command.OrderNo, cancellationToken);
+        if (order.Status != OrderStatus.Pending)
+        {
+            throw new CommerceException("Only pending orders can create payments.", "order_status_invalid");
+        }
+
+        var provider = NormalizeProvider(command.Provider);
+        var method = NormalizeMethod(command.Method);
+        var payment = await dbContext.Payments
+            .Where(item =>
+                item.TenantId == actor.TenantId &&
+                item.OrderId == order.Id &&
+                item.Provider == provider &&
+                item.Status == PaymentStatus.Pending)
+            .OrderByDescending(item => item.CreatedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+
+        if (payment is null)
+        {
+            payment = new Payment
+            {
+                TenantId = actor.TenantId,
+                OrderId = order.Id,
+                Provider = provider,
+                Method = method,
+                Status = PaymentStatus.Pending,
+                AmountCents = order.AmountCents
+            };
+            dbContext.Payments.Add(payment);
+        }
+
+        var result = await paymentGateway.CreatePaymentAsync(
+            provider,
+            new CreatePaymentProviderRequest(
+                actor.TenantId,
+                order.OrderNo,
+                order.ProductName ?? order.OrderNo,
+                order.AmountCents,
+                method,
+                command.OpenId,
+                command.ReturnUrl,
+                command.QuitUrl,
+                $"/api/commerce/payments/notify/{provider.Replace("_", "-", StringComparison.Ordinal)}?tenantId={actor.TenantId}",
+                JsonSerializer.SerializeToElement(new { order.Id, actor.UserId })),
+            cancellationToken);
+
+        payment.Method = result.Method;
+        payment.RawPayload = result.RawPayload;
+        if (!string.IsNullOrWhiteSpace(result.ProviderTradeNo))
+        {
+            payment.ProviderTradeNo = result.ProviderTradeNo;
+        }
+
+        if (IsPaid(result.Status))
+        {
+            await MarkPaidAsync(actor, order, payment, result.ProviderTradeNo, result.RawPayload, cancellationToken);
+        }
+        else
+        {
+            dbContext.PaymentEvents.Add(new PaymentEvent
+            {
+                TenantId = actor.TenantId,
+                PaymentId = payment.Id,
+                Provider = provider,
+                EventType = "payment_created",
+                Payload = result.RawPayload
+            });
+        }
+
+        await dbContext.SaveChangesAsync(cancellationToken);
+        return ToPaymentItem(payment, order.OrderNo, result.ClientPayload);
+    }
+
+    public async Task<CurrentEntitlementItem> GetCurrentEntitlementAsync(
+        CommerceActor actor,
+        CancellationToken cancellationToken = default)
+    {
+        await AssertActiveMemberAsync(actor, cancellationToken);
+        var now = DateTimeOffset.UtcNow;
+        var entitlement = await dbContext.Entitlements
+            .AsNoTracking()
+            .Where(item =>
+                item.TenantId == actor.TenantId &&
+                item.UserId == actor.UserId &&
+                item.EntitlementType == "svip" &&
+                item.Status == EntitlementStatus.Active &&
+                (item.ExpiresAt == null || item.ExpiresAt > now))
+            .OrderByDescending(item => item.ExpiresAt)
+            .FirstOrDefaultAsync(cancellationToken);
+
+        if (entitlement is null)
+        {
+            return new CurrentEntitlementItem(false, "svip", null, null, "inactive", null);
+        }
+
+        return new CurrentEntitlementItem(
+            true,
+            entitlement.EntitlementType,
+            entitlement.StartsAt,
+            entitlement.ExpiresAt,
+            entitlement.Status.ToString(),
+            entitlement.ExpiresAt.HasValue
+                ? Math.Max(0, (int)Math.Ceiling((entitlement.ExpiresAt.Value - now).TotalDays))
+                : null);
+    }
+
+    private async Task MarkPaidAsync(
+        CommerceActor actor,
+        Order order,
+        Payment payment,
+        string? providerTradeNo,
+        JsonElement rawPayload,
+        CancellationToken cancellationToken)
+    {
+        var paidAt = DateTimeOffset.UtcNow;
+        payment.Status = PaymentStatus.Paid;
+        payment.ProviderTradeNo = providerTradeNo ?? payment.ProviderTradeNo;
+        payment.PaidAt = paidAt;
+        order.Status = OrderStatus.Paid;
+        order.TradeNo = payment.ProviderTradeNo;
+        order.PaidAt = paidAt;
+
+        var days = Math.Max(order.Days ?? 0, 0);
+        var current = await dbContext.Entitlements
+            .Where(item =>
+                item.TenantId == actor.TenantId &&
+                item.UserId == actor.UserId &&
+                item.EntitlementType == "svip" &&
+                item.Status == EntitlementStatus.Active)
+            .OrderByDescending(item => item.ExpiresAt)
+            .FirstOrDefaultAsync(cancellationToken);
+        if (current is null)
+        {
+            dbContext.Entitlements.Add(new Entitlement
+            {
+                TenantId = actor.TenantId,
+                UserId = actor.UserId,
+                EntitlementType = "svip",
+                ScopeType = EntitlementScopeType.Tenant,
+                SourceType = "order",
+                SourceId = order.Id,
+                StartsAt = paidAt,
+                ExpiresAt = days > 0 ? paidAt.AddDays(days) : null,
+                Status = EntitlementStatus.Active,
+                Metadata = rawPayload
+            });
+        }
+        else if (days > 0)
+        {
+            var baseAt = current.ExpiresAt.HasValue && current.ExpiresAt > paidAt
+                ? current.ExpiresAt.Value
+                : paidAt;
+            current.ExpiresAt = baseAt.AddDays(days);
+            current.Metadata = rawPayload;
+        }
+
+        dbContext.PaymentEvents.Add(new PaymentEvent
+        {
+            TenantId = actor.TenantId,
+            PaymentId = payment.Id,
+            Provider = payment.Provider,
+            EventType = "payment_paid",
+            EventId = payment.ProviderTradeNo,
+            SignatureValid = true,
+            Payload = rawPayload,
+            ProcessedAt = paidAt
+        });
+    }
+
+    private async Task AssertActiveMemberAsync(CommerceActor actor, CancellationToken cancellationToken)
+    {
+        var exists = await dbContext.TenantMemberships.AnyAsync(item =>
+            item.TenantId == actor.TenantId &&
+            item.UserId == actor.UserId &&
+            item.Status == MembershipStatus.Active,
+            cancellationToken);
+        if (!exists)
+        {
+            throw new CommerceException("Current user is not a member of the tenant.", "tenant_access_denied");
+        }
+    }
+
+    private async Task<Order> FindActorOrderAsync(
+        CommerceActor actor,
+        string orderNo,
+        CancellationToken cancellationToken)
+    {
+        var trimmed = orderNo.Trim();
+        return await dbContext.Orders
+            .SingleOrDefaultAsync(item =>
+                item.TenantId == actor.TenantId &&
+                item.UserId == actor.UserId &&
+                item.OrderNo == trimmed,
+                cancellationToken)
+            ?? throw new CommerceException("Order was not found.", "order_not_found");
+    }
+
+    private static CommerceOrderItem ToOrderItem(Order order)
+    {
+        return new CommerceOrderItem(
+            order.Id,
+            order.OrderNo,
+            order.Status.ToString(),
+            order.PlanId,
+            order.RegionId,
+            order.ProductType,
+            order.ProductName,
+            order.AmountCents,
+            FormatCny(order.AmountCents),
+            order.PayMethod,
+            order.PayProvider,
+            order.TradeNo,
+            order.Days,
+            order.PaidAt,
+            order.CreatedAt,
+            order.RawPayload);
+    }
+
+    private static CommercePaymentItem ToPaymentItem(Payment payment, string orderNo, JsonElement clientPayload)
+    {
+        return new CommercePaymentItem(
+            payment.Id,
+            payment.OrderId,
+            orderNo,
+            payment.Provider,
+            payment.Method,
+            payment.Status.ToString(),
+            payment.AmountCents,
+            FormatCny(payment.AmountCents),
+            payment.ProviderTradeNo,
+            payment.PaidAt,
+            clientPayload,
+            payment.RawPayload);
+    }
+
+    private static OrderStatus ParseOrderStatus(string? status)
+    {
+        return Enum.TryParse<OrderStatus>(NormalizeEnum(status), true, out var parsed)
+            ? parsed
+            : throw new CommerceException("Order status is invalid.", "invalid_order_status");
+    }
+
+    private static string NormalizeEnum(string? value) =>
+        string.Concat((value ?? string.Empty).Split(
+            ['_', '-', ' '],
+            StringSplitOptions.RemoveEmptyEntries));
+
+    private static string NormalizeProvider(string? provider)
+    {
+        var normalized = (provider ?? PaymentProviders.Manual)
+            .Trim()
+            .ToLowerInvariant()
+            .Replace("-", "_", StringComparison.Ordinal);
+
+        return normalized switch
+        {
+            "" => PaymentProviders.Manual,
+            "wechat" or "wechatpay" or "wxpay" or "wx_pay" => PaymentProviders.WechatPay,
+            "ali_pay" => PaymentProviders.Alipay,
+            PaymentProviders.WechatPay or PaymentProviders.Alipay or PaymentProviders.Manual => normalized,
+            _ => throw new CommerceException("Payment provider is invalid.", "invalid_payment_provider")
+        };
+    }
+
+    private static string NormalizeMethod(string? method)
+    {
+        var normalized = (method ?? "manual").Trim().ToLowerInvariant();
+        return string.IsNullOrWhiteSpace(normalized) ? "manual" : normalized;
+    }
+
+    private static bool IsPaid(string status) =>
+        string.Equals(status, "paid", StringComparison.OrdinalIgnoreCase) ||
+        string.Equals(status, "success", StringComparison.OrdinalIgnoreCase) ||
+        string.Equals(status, "succeeded", StringComparison.OrdinalIgnoreCase);
+
+    private static string GenerateOrderNo()
+    {
+        Span<byte> bytes = stackalloc byte[4];
+        RandomNumberGenerator.Fill(bytes);
+        return $"TK{DateTimeOffset.UtcNow:yyyyMMddHHmmss}{Convert.ToHexString(bytes)}";
+    }
+
+    private static string FormatCny(int cents) =>
+        (cents / 100m).ToString("0.00", CultureInfo.InvariantCulture);
+}
diff --git a/Tiku.Infrastructure/DependencyInjection.cs b/Tiku.Infrastructure/DependencyInjection.cs
index ca6b278..9fc55c5 100644
--- a/Tiku.Infrastructure/DependencyInjection.cs
+++ b/Tiku.Infrastructure/DependencyInjection.cs
@@ -63,6 +63,7 @@ public static class DependencyInjection
         services.AddScoped<IAssetManagementService, AssetManagementService>();
         services.AddScoped<ILearningActivityService, LearningActivityService>();
         services.AddScoped<ITenantAdminDirectService, TenantAdminDirectService>();
+        services.AddScoped<ICommerceService, CommerceService>();
         services.AddScoped<ITenantSecretService, TenantSecretService>();
         services.AddScoped<IPaymentProviderConfigService, PaymentProviderConfigService>();
         services.AddScoped<IPaymentProviderGateway, PaymentProviderGateway>();
diff --git a/Tiku.IntegrationTests/Api/ApiTestFactory.cs b/Tiku.IntegrationTests/Api/ApiTestFactory.cs
index 850be9e..2fbba9f 100644
--- a/Tiku.IntegrationTests/Api/ApiTestFactory.cs
+++ b/Tiku.IntegrationTests/Api/ApiTestFactory.cs
@@ -2,6 +2,7 @@ using Microsoft.AspNetCore.Mvc.Testing;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Npgsql;
+using Tiku.Application.Commerce;
 using Tiku.Application.Auth;
 using Tiku.Application.Storage;
 using Tiku.Domain.Identity;
@@ -12,7 +13,8 @@ namespace Tiku.IntegrationTests.Api;
 
 public sealed class ApiTestFactory(
     IWechatOAuthClient? wechatOAuthClient = null,
-    IObjectStorageService? objectStorageService = null) : WebApplicationFactory<Program>
+    IObjectStorageService? objectStorageService = null,
+    IPaymentProviderGateway? paymentProviderGateway = null) : WebApplicationFactory<Program>
 {
     private readonly string databaseName = Guid.NewGuid().ToString();
 
@@ -42,6 +44,11 @@ public sealed class ApiTestFactory(
             {
                 services.AddSingleton(objectStorageService);
             }
+
+            if (paymentProviderGateway is not null)
+            {
+                services.AddSingleton(paymentProviderGateway);
+            }
         });
     }
 
diff --git a/Tiku.IntegrationTests/Api/CommerceEndpointTests.cs b/Tiku.IntegrationTests/Api/CommerceEndpointTests.cs
new file mode 100644
index 0000000..e5f3321
--- /dev/null
+++ b/Tiku.IntegrationTests/Api/CommerceEndpointTests.cs
@@ -0,0 +1,318 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Net;
+using System.Net.Http.Json;
+using System.Security.Claims;
+using System.Text;
+using System.Text.Json;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.IdentityModel.Tokens;
+using Tiku.Api.Contracts;
+using Tiku.Api.Options;
+using Tiku.Application.Auth;
+using Tiku.Application.Commerce;
+using Tiku.Application.Security;
+using Tiku.Domain.Commerce;
+using Tiku.Domain.Identity;
+using Tiku.Domain.Tenancy;
+using Tiku.Infrastructure.Auth;
+using Tiku.Infrastructure.Persistence;
+
+namespace Tiku.IntegrationTests.Api;
+
+public sealed class CommerceEndpointTests
+{
+    private static readonly JwtOptions JwtOptions = new()
+    {
+        Issuer = "tiku-backend",
+        Audience = "tiku-api",
+        SigningKey = "development-only-tiku-signing-key-change-before-production"
+    };
+
+    [Fact]
+    public async Task Anonymous_commerce_request_returns_401()
+    {
+        await using var factory = new ApiTestFactory(paymentProviderGateway: new FakePaymentGateway());
+        using var client = factory.CreateClient();
+
+        var response = await client.GetAsync("/api/commerce/orders");
+
+        Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task Non_member_cannot_create_order()
+    {
+        await using var factory = new ApiTestFactory(paymentProviderGateway: new FakePaymentGateway());
+        var tenantId = Guid.NewGuid();
+        var userId = Guid.NewGuid();
+        var sessionId = await factory.SeedActiveSessionAsync(userId, tenantId);
+        var planId = Guid.NewGuid();
+        await factory.SeedAsync(
+            new SvipPlan
+            {
+                Id = planId,
+                TenantId = tenantId,
+                Name = "月卡",
+                PriceCents = 999,
+                Days = 39,
+                IsActive = true
+            });
+        using var client = factory.CreateClient();
+        client.DefaultRequestHeaders.Authorization = new(
+            "Bearer",
+            CreateToken([
+                new Claim(TikuClaimTypes.UserId, userId.ToString()),
+                new Claim(TikuClaimTypes.SessionId, sessionId.ToString()),
+                new Claim(TikuClaimTypes.TenantId, tenantId.ToString()),
+                new Claim(TikuClaimTypes.TenantRole, TenantRole.Student.ToString())
+            ]));
+
+        var response = await client.PostAsJsonAsync(
+            "/api/commerce/orders",
+            new CreateCommerceOrderDto
+            {
+                PlanId = planId,
+                Quantity = 1
+            });
+
+        Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task Student_can_create_and_query_svip_order()
+    {
+        await using var factory = new ApiTestFactory(paymentProviderGateway: new FakePaymentGateway());
+        var seed = await SeedLoginUserAsync(factory);
+        using var client = factory.CreateClient();
+        await LoginAsync(client, seed);
+
+        var createResponse = await client.PostAsJsonAsync(
+            "/api/commerce/orders",
+            new CreateCommerceOrderDto
+            {
+                PlanId = seed.PlanId,
+                Quantity = 2,
+                PayMethod = "manual",
+                PayProvider = "manual"
+            });
+        var created = await createResponse.Content.ReadFromJsonAsync<CommerceOrderItem>();
+        var listResponse = await client.GetAsync("/api/commerce/orders?limit=5");
+        var list = await listResponse.Content.ReadFromJsonAsync<CommerceOrderList>();
+        var detailResponse = await client.GetAsync($"/api/commerce/orders/{created!.OrderNo}");
+
+        Assert.Equal(HttpStatusCode.OK, createResponse.StatusCode);
+        Assert.Equal(1998, created.AmountCents);
+        Assert.Equal(78, created.Days);
+        Assert.Equal(HttpStatusCode.OK, listResponse.StatusCode);
+        Assert.Contains(list!.Items, item => item.OrderNo == created.OrderNo);
+        Assert.Equal(HttpStatusCode.OK, detailResponse.StatusCode);
+    }
+
+    [Fact]
+    public async Task Paid_provider_result_marks_order_paid_and_grants_entitlement()
+    {
+        await using var factory = new ApiTestFactory(paymentProviderGateway: new FakePaymentGateway("paid"));
+        var seed = await SeedLoginUserAsync(factory);
+        using var client = factory.CreateClient();
+        await LoginAsync(client, seed);
+        var order = await CreateOrderAsync(client, seed.PlanId);
+
+        var paymentResponse = await client.PostAsJsonAsync(
+            "/api/commerce/payments",
+            new CreateCommercePaymentDto
+            {
+                OrderNo = order.OrderNo,
+                Provider = "manual",
+                Method = "manual"
+            });
+        var payment = await paymentResponse.Content.ReadFromJsonAsync<CommercePaymentItem>();
+        var entitlementResponse = await client.GetAsync("/api/commerce/entitlements/current");
+        var entitlement = await entitlementResponse.Content.ReadFromJsonAsync<CurrentEntitlementItem>();
+        var orderResponse = await client.GetAsync($"/api/commerce/orders/{order.OrderNo}");
+        var paidOrder = await orderResponse.Content.ReadFromJsonAsync<CommerceOrderItem>();
+
+        Assert.Equal(HttpStatusCode.OK, paymentResponse.StatusCode);
+        Assert.Equal("Paid", payment!.Status);
+        Assert.Equal("Paid", paidOrder!.Status);
+        Assert.Equal(HttpStatusCode.OK, entitlementResponse.StatusCode);
+        Assert.True(entitlement!.IsActive);
+        Assert.Equal("svip", entitlement.EntitlementType);
+    }
+
+    [Fact]
+    public async Task Pending_payment_can_be_requested_idempotently()
+    {
+        await using var factory = new ApiTestFactory(paymentProviderGateway: new FakePaymentGateway());
+        var seed = await SeedLoginUserAsync(factory);
+        using var client = factory.CreateClient();
+        await LoginAsync(client, seed);
+        var order = await CreateOrderAsync(client, seed.PlanId);
+        var request = new CreateCommercePaymentDto
+        {
+            OrderNo = order.OrderNo,
+            Provider = "manual",
+            Method = "manual"
+        };
+
+        var first = await client.PostAsJsonAsync("/api/commerce/payments", request);
+        var second = await client.PostAsJsonAsync("/api/commerce/payments", request);
+        var firstPayment = await first.Content.ReadFromJsonAsync<CommercePaymentItem>();
+        var secondPayment = await second.Content.ReadFromJsonAsync<CommercePaymentItem>();
+
+        Assert.Equal(HttpStatusCode.OK, first.StatusCode);
+        Assert.Equal(HttpStatusCode.OK, second.StatusCode);
+        Assert.Equal(firstPayment!.Id, secondPayment!.Id);
+    }
+
+    private static async Task<CommerceOrderItem> CreateOrderAsync(HttpClient client, Guid planId)
+    {
+        var response = await client.PostAsJsonAsync(
+            "/api/commerce/orders",
+            new CreateCommerceOrderDto
+            {
+                PlanId = planId,
+                Quantity = 1,
+                PayMethod = "manual",
+                PayProvider = "manual"
+            });
+        response.EnsureSuccessStatusCode();
+        return (await response.Content.ReadFromJsonAsync<CommerceOrderItem>())!;
+    }
+
+    private static async Task<LoginSeed> SeedLoginUserAsync(
+        ApiTestFactory factory,
+        bool includeMembership = true)
+    {
+        var tenantId = Guid.NewGuid();
+        var userId = Guid.NewGuid();
+        var planId = Guid.NewGuid();
+        var phone = "13800000000";
+        var passwordHash = new PasswordHasher().Hash("passw0rd!");
+        var entities = new List<object>
+        {
+            new Tenant
+            {
+                Id = tenantId,
+                Slug = tenantId.ToString("N"),
+                Name = "Commerce Tenant"
+            },
+            new User
+            {
+                Id = userId,
+                Phone = phone,
+                Name = "Commerce User"
+            },
+            new UserIdentity
+            {
+                UserId = userId,
+                Provider = "password",
+                ProviderSubject = phone,
+                Phone = phone,
+                SecretPayload = CreateSecretPayload(passwordHash)
+            },
+            new SvipPlan
+            {
+                Id = planId,
+                TenantId = tenantId,
+                Name = "月卡",
+                PriceCents = 999,
+                Days = 39,
+                IsActive = true
+            },
+            new TenantPaymentAccount
+            {
+                TenantId = tenantId,
+                Provider = "manual",
+                Status = TenantPaymentAccountStatus.Active
+            }
+        };
+        if (includeMembership)
+        {
+            entities.Add(new TenantMembership
+            {
+                TenantId = tenantId,
+                UserId = userId,
+                Role = TenantRole.Student,
+                Status = MembershipStatus.Active
+            });
+        }
+
+        await factory.SeedAsync(entities.ToArray());
+        return new LoginSeed(tenantId, userId, planId, phone);
+    }
+
+    private static async Task LoginAsync(HttpClient client, LoginSeed seed)
+    {
+        var loginResponse = await client.PostAsJsonAsync(
+            "/api/auth/login/password",
+            new PasswordLoginDto
+            {
+                TenantId = seed.TenantId,
+                Phone = seed.Phone,
+                Password = "passw0rd!"
+            });
+        loginResponse.EnsureSuccessStatusCode();
+        using var loginJson = await JsonDocument.ParseAsync(await loginResponse.Content.ReadAsStreamAsync());
+        var accessToken = loginJson.RootElement
+            .GetProperty("tokens")
+            .GetProperty("accessToken")
+            .GetString();
+        client.DefaultRequestHeaders.Authorization = new("Bearer", accessToken);
+    }
+
+    private static JsonElement CreateSecretPayload(string passwordHash)
+    {
+        using var document = JsonDocument.Parse(
+            $$"""{"passwordHash":{{JsonSerializer.Serialize(passwordHash)}}}""");
+        return document.RootElement.Clone();
+    }
+
+    private static string CreateToken(IEnumerable<Claim> claims)
+    {
+        var credentials = new SigningCredentials(
+            new SymmetricSecurityKey(Encoding.UTF8.GetBytes(JwtOptions.SigningKey)),
+            SecurityAlgorithms.HmacSha256);
+
+        var token = new JwtSecurityToken(
+            JwtOptions.Issuer,
+            JwtOptions.Audience,
+            claims,
+            expires: DateTime.UtcNow.AddMinutes(5),
+            signingCredentials: credentials);
+
+        return new JwtSecurityTokenHandler().WriteToken(token);
+    }
+
+    private sealed record LoginSeed(Guid TenantId, Guid UserId, Guid PlanId, string Phone);
+
+    private sealed class FakePaymentGateway(string status = "pending") : IPaymentProviderGateway
+    {
+        public Task<CreatePaymentProviderResult> CreatePaymentAsync(
+            string provider,
+            CreatePaymentProviderRequest request,
+            CancellationToken cancellationToken = default)
+        {
+            var payload = JsonSerializer.SerializeToElement(new
+            {
+                request.OrderNo,
+                request.AmountCents,
+                status
+            });
+            return Task.FromResult(new CreatePaymentProviderResult(
+                provider,
+                request.Method,
+                status,
+                status == "paid" ? $"trade-{request.OrderNo}" : null,
+                payload,
+                payload));
+        }
+
+        public Task<PaymentNotificationResult> ParsePaymentNotificationAsync(
+            string provider,
+            PaymentNotificationRequest request,
+            CancellationToken cancellationToken = default)
+        {
+            throw new NotSupportedException();
+        }
+    }
+}