Add Low-Code System documentation

Add comprehensive Low-Code System documentation and navigation. Introduces new docs under docs/en/low-code (index.md, fluent-api.md, model-json.md, scripting-api.md, interceptors.md, custom-endpoints.md, reference-entities.md, foreign-access.md) and updates docs/en/docs-nav.json to include a "Low-Code System" section linking these pages.

docs/en/docs-nav.json

@@ -1981,6 +1981,44 @@
         }
       ]
     },
+    {
+      "text": "Low-Code System",
+      "items": [
+        {
+          "text": "Overview",
+          "path": "low-code",
+          "isIndex": true
+        },
+        {
+          "text": "Fluent API & Attributes",
+          "path": "low-code/fluent-api.md"
+        },
+        {
+          "text": "model.json Structure",
+          "path": "low-code/model-json.md"
+        },
+        {
+          "text": "Reference Entities",
+          "path": "low-code/reference-entities.md"
+        },
+        {
+          "text": "Interceptors",
+          "path": "low-code/interceptors.md"
+        },
+        {
+          "text": "Scripting API",
+          "path": "low-code/scripting-api.md"
+        },
+        {
+          "text": "Custom Endpoints",
+          "path": "low-code/custom-endpoints.md"
+        },
+        {
+          "text": "Foreign Access",
+          "path": "low-code/foreign-access.md"
+        }
+      ]
+    },
     {
       "text": "Solution Templates",
       "items": [

docs/en/low-code/custom-endpoints.md

@@ -0,0 +1,131 @@
+```json
+//[doc-seo]
+{
+    "Description": "Define custom REST API endpoints with JavaScript handlers in the ABP Low-Code Module. Create dynamic APIs without writing C# controllers."
+}
+```
+
+# Custom Endpoints
+
+Custom Endpoints allow you to define REST API routes with server-side JavaScript handlers directly in `model.json`. Each endpoint is registered as an ASP.NET Core endpoint at startup and supports hot-reload when the model changes.
+
+## Defining Endpoints
+
+Add endpoints to the `endpoints` array in `model.json`:
+
+```json
+{
+  "endpoints": [
+    {
+      "name": "GetProductStats",
+      "route": "/api/custom/products/stats",
+      "method": "GET",
+      "description": "Get product statistics",
+      "requireAuthentication": false,
+      "javascript": "var count = await db.count('LowCodeDemo.Products.Product');\nreturn ok({ totalProducts: count });"
+    }
+  ]
+}
+```
+
+### Endpoint Descriptor
+
+| Field | Type | Default | Description |
+|-------|------|---------|-------------|
+| `name` | string | **Required** | Unique endpoint name |
+| `route` | string | **Required** | URL route pattern (supports `{parameters}`) |
+| `method` | string | `"GET"` | HTTP method: `GET`, `POST`, `PUT`, `DELETE` |
+| `javascript` | string | **Required** | JavaScript handler code |
+| `description` | string | null | Description for documentation |
+| `requireAuthentication` | bool | `true` | Require authenticated user |
+| `requiredPermissions` | string[] | null | Required permission names |
+
+## Route Parameters
+
+Use `{paramName}` syntax in the route. Access values via the `route` object:
+
+```json
+{
+  "name": "GetProductById",
+  "route": "/api/custom/products/{id}",
+  "method": "GET",
+  "javascript": "var product = await db.get('LowCodeDemo.Products.Product', route.id);\nif (!product) { return notFound('Product not found'); }\nreturn ok({ id: product.Id, name: product.Name, price: product.Price });"
+}
+```
+
+## JavaScript Context
+
+Inside custom endpoint scripts, you have access to:
+
+### Request Context
+
+| Variable | Description |
+|----------|-------------|
+| `route` | Route parameter values (e.g., `route.id`) |
+| `query` | Query string parameters (e.g., `query.q`, `query.page`) |
+| `body` | Request body (for POST/PUT) |
+| `user` | Current user (same as `context.currentUser` in interceptors) |
+
+### Response Helpers
+
+| Function | HTTP Status | Description |
+|----------|-------------|-------------|
+| `ok(data)` | 200 | Success response with data |
+| `notFound(message)` | 404 | Not found response |
+| `badRequest(message)` | 400 | Bad request response |
+
+### Database API
+
+The full [Scripting API](scripting-api.md) (`db` object) is available for querying and mutating data.
+
+## Examples
+
+### Get Statistics
+
+```json
+{
+  "name": "GetProductStats",
+  "route": "/api/custom/products/stats",
+  "method": "GET",
+  "requireAuthentication": false,
+  "javascript": "var totalCount = await db.count('LowCodeDemo.Products.Product');\nvar avgPrice = totalCount > 0 ? await db.query('LowCodeDemo.Products.Product').average(p => p.Price) : 0;\nreturn ok({ totalProducts: totalCount, averagePrice: avgPrice });"
+}
+```
+
+### Search with Query Parameters
+
+```json
+{
+  "name": "SearchCustomers",
+  "route": "/api/custom/customers/search",
+  "method": "GET",
+  "requireAuthentication": true,
+  "javascript": "var searchTerm = query.q || '';\nvar customers = await db.query('LowCodeDemo.Customers.Customer')\n  .where(c => c.Name.toLowerCase().includes(searchTerm.toLowerCase()))\n  .take(10)\n  .toList();\nreturn ok(customers.map(c => ({ id: c.Id, name: c.Name, email: c.EmailAddress })));"
+}
+```
+
+### Dashboard Summary
+
+```json
+{
+  "name": "GetDashboardSummary",
+  "route": "/api/custom/dashboard",
+  "method": "GET",
+  "requireAuthentication": true,
+  "javascript": "var productCount = await db.count('LowCodeDemo.Products.Product');\nvar customerCount = await db.count('LowCodeDemo.Customers.Customer');\nvar orderCount = await db.count('LowCodeDemo.Orders.Order');\nreturn ok({ products: productCount, customers: customerCount, orders: orderCount, user: user.isAuthenticated ? user.userName : 'Anonymous' });"
+}
+```
+
+## Authentication and Authorization
+
+| Setting | Behavior |
+|---------|----------|
+| `requireAuthentication: false` | Endpoint is publicly accessible |
+| `requireAuthentication: true` | User must be authenticated |
+| `requiredPermissions: ["MyApp.Products"]` | User must have the specified permissions |
+
+## See Also
+
+* [Scripting API](scripting-api.md)
+* [Interceptors](interceptors.md)
+* [model.json Structure](model-json.md)

docs/en/low-code/fluent-api.md

@@ -0,0 +1,439 @@
+```json
+//[doc-seo]
+{
+    "Description": "Define dynamic entities using C# attributes and configure them with the Fluent API in the ABP Low-Code System. The primary way to build auto-generated admin panels."
+}
+```
+
+# Fluent API & Attributes
+
+C# Attributes and the Fluent API are the **recommended way** to define dynamic entities. They provide compile-time checking, IntelliSense, refactoring support, and keep your entity definitions close to your domain code.
+
+## Quick Start
+
+### Step 1: Define an Entity
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Products")]
+public class Product
+{
+    [DynamicPropertyUnique]
+    public string Name { get; set; }
+
+    [DynamicPropertyUI(DisplayName = "Unit Price")]
+    public decimal Price { get; set; }
+
+    public int StockCount { get; set; }
+
+    public DateTime? ReleaseDate { get; set; }
+}
+````
+
+### Step 2: Register the Assembly
+
+````csharp
+public override void ConfigureServices(ServiceConfigurationContext context)
+{
+    AbpDynamicEntityConfig.SourceAssemblies.Add(
+        new DynamicEntityAssemblyInfo(typeof(YourDomainModule).Assembly)
+    );
+}
+````
+
+### Step 3: Add Migration and Run
+
+```bash
+dotnet ef migrations add Added_Product
+dotnet ef database update
+```
+
+You now have a complete Product management page with data grid, create/edit modals, search, sorting, and pagination.
+
+### Step 4: Add Relationships
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Orders")]
+public class Order
+{
+    [DynamicForeignKey("MyApp.Customers.Customer", "Name", ForeignAccess.Edit)]
+    public Guid CustomerId { get; set; }
+
+    public decimal TotalAmount { get; set; }
+    public bool IsDelivered { get; set; }
+}
+
+[DynamicEntity(Parent = "MyApp.Orders.Order")]
+public class OrderLine
+{
+    [DynamicForeignKey("MyApp.Products.Product", "Name")]
+    public Guid ProductId { get; set; }
+
+    public int Quantity { get; set; }
+    public decimal Amount { get; set; }
+}
+````
+
+The `Order` page now has a foreign key dropdown for Customer, and `OrderLine` is managed as a nested child inside the Order detail modal.
+
+## Three-Layer Configuration System
+
+The Low-Code System uses a layered configuration model. From lowest to highest priority:
+
+1. **Code Layer** — C# classes with `[DynamicEntity]` and other attributes
+2. **JSON Layer** — `model.json` file (see [model.json Structure](model-json.md))
+3. **Fluent Layer** — `AbpDynamicEntityConfig.EntityConfigurations`
+
+A `DefaultsLayer` runs last to fill in any missing values with conventions.
+
+> When the same entity or property is configured in multiple layers, the higher-priority layer wins.
+
+## C# Attributes Reference
+
+### `[DynamicEntity]`
+
+Marks a class as a dynamic entity. The entity name is derived from the class namespace and name.
+
+````csharp
+[DynamicEntity]
+public class Product
+{
+    public string Name { get; set; }
+    public decimal Price { get; set; }
+}
+````
+
+Use the `Parent` property for parent-child (master-detail) relationships:
+
+````csharp
+[DynamicEntity(Parent = "MyApp.Orders.Order")]
+public class OrderLine
+{
+    public Guid ProductId { get; set; }
+    public int Quantity { get; set; }
+}
+````
+
+### `[DynamicEntityUI]`
+
+Configures entity-level UI. Entities with `PageTitle` get a menu item and a dedicated page:
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Product Management")]
+public class Product
+{
+    // ...
+}
+````
+
+### `[DynamicForeignKey]`
+
+Defines a foreign key relationship on a `Guid` property:
+
+````csharp
+[DynamicForeignKey("MyApp.Customers.Customer", "Name", ForeignAccess.Edit)]
+public Guid CustomerId { get; set; }
+````
+
+| Parameter | Description |
+|-----------|-------------|
+| `entityName` | Full name of the referenced entity (or [reference entity](reference-entities.md)) |
+| `displayPropertyName` | Property to show in lookups |
+| `access` | `ForeignAccess.None`, `ForeignAccess.View`, or `ForeignAccess.Edit` (see [Foreign Access](foreign-access.md)) |
+
+### `[DynamicPropertyUI]`
+
+Controls property visibility and behavior in the UI:
+
+````csharp
+[DynamicPropertyUI(
+    DisplayName = "Registration Number",
+    IsAvailableOnListing = true,
+    IsAvailableOnDataTableFiltering = true,
+    CreationFormAvailability = EntityPropertyUIFormAvailability.Hidden,
+    EditingFormAvailability = EntityPropertyUIFormAvailability.NotAvailable,
+    QuickLookOrder = 100
+)]
+public string RegistrationNumber { get; set; }
+````
+
+| Property | Type | Default | Description |
+|----------|------|---------|-------------|
+| `DisplayName` | string | null | Custom label for the property |
+| `IsAvailableOnListing` | bool | `true` | Show in data grid |
+| `IsAvailableOnDataTableFiltering` | bool | `true` | Show in filter panel |
+| `CreationFormAvailability` | enum | `Available` | Visibility on create form |
+| `EditingFormAvailability` | enum | `Available` | Visibility on edit form |
+| `QuickLookOrder` | int | `-2` | Order in quick-look panel |
+
+### `[DynamicPropertyServerOnly]`
+
+Hides a property from API clients entirely. It is stored in the database but never returned to the client:
+
+````csharp
+[DynamicPropertyServerOnly]
+public string InternalNotes { get; set; }
+````
+
+### `[DynamicPropertySetByClients]`
+
+Controls whether clients can set this property value. Useful for computed or server-assigned fields:
+
+````csharp
+[DynamicPropertySetByClients(Allow = false)]
+public string RegistrationNumber { get; set; }
+````
+
+### `[DynamicPropertyUnique]`
+
+Marks a property as requiring unique values across all records:
+
+````csharp
+[DynamicPropertyUnique]
+public string ProductCode { get; set; }
+````
+
+### `[DynamicEntityCommandInterceptor]`
+
+Defines JavaScript interceptors on a class for CRUD lifecycle hooks:
+
+````csharp
+[DynamicEntity]
+[DynamicEntityCommandInterceptor(
+    "Create",
+    InterceptorType.Pre,
+    "if(!context.commandArgs.data['Name']) { globalError = 'Name is required!'; }"
+)]
+[DynamicEntityCommandInterceptor(
+    "Delete",
+    InterceptorType.Post,
+    "context.log('Deleted: ' + context.commandArgs.entityId);"
+)]
+public class Organization
+{
+    public string Name { get; set; }
+}
+````
+
+> The `Name` parameter must be one of: `"Create"`, `"Update"`, or `"Delete"`. Multiple interceptors can be added to the same class (`AllowMultiple = true`).
+
+See [Interceptors](interceptors.md) for the full JavaScript context API.
+
+### `[DynamicEnum]`
+
+Marks an enum for use in dynamic entity properties:
+
+````csharp
+[DynamicEnum]
+public enum OrganizationType
+{
+    Corporate = 0,
+    Enterprise = 1,
+    Startup = 2,
+    Consulting = 3
+}
+````
+
+Reference in an entity:
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Organizations")]
+public class Organization
+{
+    public string Name { get; set; }
+    public OrganizationType OrganizationType { get; set; }
+}
+````
+
+## Fluent API
+
+The Fluent API has the **highest priority** in the configuration system. Use `AbpDynamicEntityConfig.EntityConfigurations` to override any attribute or JSON setting programmatically.
+
+### Basic Usage
+
+Configure in your Domain module's `ConfigureServices`:
+
+````csharp
+public override void ConfigureServices(ServiceConfigurationContext context)
+{
+    AbpDynamicEntityConfig.EntityConfigurations.Configure(
+        "MyApp.Products.Product",
+        entity =>
+        {
+            entity.SetDisplayProperty("Name");
+
+            entity.ConfigureProperty("Price", prop =>
+            {
+                prop.SetRequired(true);
+                prop.SetUI(ui =>
+                {
+                    ui.SetDisplayName("Unit Price");
+                    ui.SetCreationFormAvailability(EntityPropertyUIFormAvailability.Available);
+                });
+            });
+
+            entity.ConfigureProperty("InternalNotes", prop =>
+            {
+                prop.SetServerOnly(true);
+            });
+        }
+    );
+}
+````
+
+### Entity Configuration Methods
+
+| Method | Description |
+|--------|-------------|
+| `SetDisplayProperty(name)` | Set the display property for lookups |
+| `SetParent(entityName)` | Set parent entity for nesting |
+| `SetUI(action)` | Configure entity-level UI |
+| `ConfigureProperty(name, action)` | Configure a specific property |
+| `AddInterceptor(name, type, js)` | Add a JavaScript interceptor |
+
+### Property Configuration Methods
+
+| Method | Description |
+|--------|-------------|
+| `SetRequired(bool)` | Mark as required |
+| `SetUnique(bool)` | Mark as unique |
+| `SetServerOnly(bool)` | Hide from clients |
+| `SetAllowSetByClients(bool)` | Allow client writes |
+| `SetForeignKey(entityName, displayProp, access)` | Configure foreign key |
+| `SetUI(action)` | Configure property UI |
+
+## Assembly Registration
+
+Register assemblies containing `[DynamicEntity]` classes:
+
+````csharp
+AbpDynamicEntityConfig.SourceAssemblies.Add(
+    new DynamicEntityAssemblyInfo(typeof(MyDomainModule).Assembly)
+);
+````
+
+You can also register entity types directly:
+
+````csharp
+AbpDynamicEntityConfig.DynamicEntityTypes.Add(typeof(Product));
+AbpDynamicEntityConfig.DynamicEnumTypes.Add(typeof(OrganizationType));
+````
+
+## Combining with model.json
+
+Attributes and model.json work together seamlessly. A common pattern:
+
+1. **Define core entities** with C# attributes (compile-time safety)
+2. **Add additional entities** via model.json (no recompilation needed)
+3. **Fine-tune configuration** with Fluent API (overrides everything)
+
+The three-layer system merges all definitions:
+
+```
+Fluent API (highest) > JSON (model.json) > Code (Attributes) > Defaults (lowest)
+```
+
+For example, if an attribute sets `[DynamicPropertyUnique]` and model.json sets `"isUnique": false`, the JSON value wins because JSON layer has higher priority than Code layer.
+
+## End-to-End Example
+
+A complete e-commerce-style entity setup:
+
+````csharp
+// Enum
+[DynamicEnum]
+public enum OrderStatus
+{
+    Pending = 0,
+    Processing = 1,
+    Shipped = 2,
+    Delivered = 3
+}
+
+// Customer entity
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Customers")]
+public class Customer
+{
+    [DynamicPropertyUnique]
+    public string Name { get; set; }
+
+    [DynamicPropertyUI(DisplayName = "Phone Number", QuickLookOrder = 100)]
+    public string Telephone { get; set; }
+
+    [DynamicForeignKey("Volo.Abp.Identity.IdentityUser", "UserName")]
+    public Guid? UserId { get; set; }
+
+    [DynamicPropertyServerOnly]
+    public string InternalNotes { get; set; }
+}
+
+// Product entity
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Products")]
+public class Product
+{
+    [DynamicPropertyUnique]
+    public string Name { get; set; }
+
+    public decimal Price { get; set; }
+    public int StockCount { get; set; }
+}
+
+// Order entity with child OrderLine
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Orders")]
+[DynamicEntityCommandInterceptor(
+    "Update",
+    InterceptorType.Pre,
+    @"if(context.commandArgs.data['IsDelivered']) {
+        if(!context.currentUser.roles.includes('admin')) {
+            globalError = 'Only admins can mark as delivered!';
+        }
+    }"
+)]
+public class Order
+{
+    [DynamicForeignKey("MyApp.Customers.Customer", "Name", ForeignAccess.Edit)]
+    public Guid CustomerId { get; set; }
+
+    public decimal TotalAmount { get; set; }
+    public bool IsDelivered { get; set; }
+    public OrderStatus Status { get; set; }
+}
+
+[DynamicEntity(Parent = "MyApp.Orders.Order")]
+public class OrderLine
+{
+    [DynamicForeignKey("MyApp.Products.Product", "Name")]
+    public Guid ProductId { get; set; }
+
+    public int Quantity { get; set; }
+    public decimal Amount { get; set; }
+}
+````
+
+Register everything in your Domain module:
+
+````csharp
+public override void ConfigureServices(ServiceConfigurationContext context)
+{
+    AbpDynamicEntityConfig.SourceAssemblies.Add(
+        new DynamicEntityAssemblyInfo(typeof(MyDomainModule).Assembly)
+    );
+
+    // Reference existing ABP entities
+    AbpDynamicEntityConfig.ReferencedEntityList.Add<IdentityUser>("UserName");
+}
+````
+
+This gives you four auto-generated pages (Customers, Products, Orders with nested OrderLines), complete with permissions, menu items, foreign key lookups, and interceptor-based business rules.
+
+## See Also
+
+* [model.json Structure](model-json.md)
+* [Reference Entities](reference-entities.md)
+* [Interceptors](interceptors.md)

docs/en/low-code/foreign-access.md

@@ -0,0 +1,137 @@
+```json
+//[doc-seo]
+{
+    "Description": "Control access to related entities through foreign key relationships using Foreign Access in the ABP Low-Code Module."
+}
+```
+
+# Foreign Access
+
+Foreign Access controls how related entities can be accessed through foreign key relationships. It determines whether users can view or manage related data directly from the referenced entity's UI.
+
+## Access Levels
+
+The `ForeignAccess` enum defines three levels:
+
+| Level | Value | Description |
+|-------|-------|-------------|
+| `None` | 0 | No access from the referenced entity side. The relationship exists only for lookups. |
+| `View` | 1 | Read-only access. Users can view related records from the referenced entity's action menu. |
+| `Edit` | 2 | Full CRUD access. Users can create, update, and delete related records from the referenced entity's action menu. |
+
+## Configuring with Attributes
+
+Use the third parameter of `[DynamicForeignKey]`:
+
+````csharp
+[DynamicEntity]
+public class Order
+{
+    [DynamicForeignKey("MyApp.Customers.Customer", "Name", ForeignAccess.Edit)]
+    public Guid CustomerId { get; set; }
+}
+````
+
+## Configuring with Fluent API
+
+````csharp
+AbpDynamicEntityConfig.EntityConfigurations.Configure(
+    "MyApp.Orders.Order",
+    entity =>
+    {
+        entity.ConfigureProperty("CustomerId", prop =>
+        {
+            prop.SetForeignKey("MyApp.Customers.Customer", "Name", ForeignAccess.Edit);
+        });
+    }
+);
+````
+
+## Configuring in model.json
+
+Set the `access` field on a foreign key property:
+
+```json
+{
+  "name": "CustomerId",
+  "foreignKey": {
+    "entityName": "LowCodeDemo.Customers.Customer",
+    "displayPropertyName": "Name",
+    "access": "edit"
+  }
+}
+```
+
+### Examples from the Demo Application
+
+**Edit access** — Orders can be managed from the Customer page:
+
+```json
+{
+  "name": "LowCodeDemo.Orders.Order",
+  "properties": [
+    {
+      "name": "CustomerId",
+      "foreignKey": {
+        "entityName": "LowCodeDemo.Customers.Customer",
+        "access": "edit"
+      }
+    }
+  ]
+}
+```
+
+**View access** — Visited countries are viewable from the Country page:
+
+```json
+{
+  "name": "LowCodeDemo.Customers.VisitedCountry",
+  "parent": "LowCodeDemo.Customers.Customer",
+  "properties": [
+    {
+      "name": "CountryId",
+      "foreignKey": {
+        "entityName": "LowCodeDemo.Countries.Country",
+        "access": "view"
+      }
+    }
+  ]
+}
+```
+
+## UI Behavior
+
+When foreign access is configured:
+
+### `ForeignAccess.View`
+
+An **action menu item** appears on the referenced entity's data grid row (e.g., a "Visited Countries" item on the Country row). Clicking it opens a read-only modal showing related records.
+
+### `ForeignAccess.Edit`
+
+An **action menu item** appears on the referenced entity's data grid row (e.g., an "Orders" item on the Customer row). Clicking it opens a fully functional CRUD modal where users can create, edit, and delete related records.
+
+### `ForeignAccess.None`
+
+No action menu item is added. The foreign key exists only for data integrity and lookup display.
+
+## Permission Control
+
+Foreign access actions respect the **entity permissions** of the related entity. For example, if a user does not have the `Delete` permission for `Order`, the delete button will not appear in the foreign access modal, even if the access level is `Edit`.
+
+## How It Works
+
+The `ForeignAccessRelation` class stores the relationship metadata:
+
+* Source entity (the entity with the foreign key)
+* Target entity (the referenced entity)
+* Foreign key property name
+* Access level
+
+The `DynamicEntityAppService` checks these relations when building entity actions and filtering data.
+
+## See Also
+
+* [model.json Structure](model-json.md)
+* [Reference Entities](reference-entities.md)
+* [Fluent API & Attributes](fluent-api.md)

docs/en/low-code/index.md

@@ -0,0 +1,228 @@
+```json
+//[doc-seo]
+{
+    "Description": "ABP Low-Code System: Build admin panels with auto-generated CRUD UI, APIs, and permissions using C# attributes and Fluent API. No boilerplate code needed."
+}
+```
+
+# Low-Code System
+
+The ABP Low-Code System lets you define entities using C# attributes or Fluent API and automatically generates:
+
+* **Database tables** (via EF Core migrations)
+* **CRUD REST APIs** (Get, GetList, Create, Update, Delete)
+* **Permissions** (View, Create, Update, Delete per entity)
+* **Menu items** (auto-added to the admin sidebar)
+* **Full Blazor UI** (data grid, create/edit modals, filters, foreign key lookups)
+
+No need to write entity classes, DTOs, application services, repositories, or UI pages manually.
+
+## Why Low-Code?
+
+Traditionally, adding a new entity to an ABP application requires:
+
+1. Entity class in Domain
+2. DbContext configuration in EF Core
+3. DTOs in Application.Contracts
+4. AppService in Application
+5. Controller in HttpApi
+6. Razor/Blazor pages in UI
+7. Permissions, menu items, localization
+
+**With Low-Code, a single C# class replaces all of the above:**
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Products")]
+public class Product
+{
+    [DynamicPropertyUnique]
+    public string Name { get; set; }
+
+    [DynamicPropertyUI(DisplayName = "Unit Price")]
+    public decimal Price { get; set; }
+
+    public int StockCount { get; set; }
+
+    [DynamicForeignKey("MyApp.Categories.Category", "Name")]
+    public Guid? CategoryId { get; set; }
+}
+````
+
+Run `dotnet ef migrations add Added_Product` and start your application. You get a complete Product management page with search, filtering, sorting, pagination, create/edit forms, and foreign key dropdown — all auto-generated.
+
+## Getting Started
+
+### 1. Install NuGet Packages
+
+| Package | Layer |
+|---------|-------|
+| `Volo.Abp.LowCode.Domain.Shared` | Domain.Shared |
+| `Volo.Abp.LowCode.Domain` | Domain |
+| `Volo.Abp.LowCode.Application.Contracts` | Application.Contracts |
+| `Volo.Abp.LowCode.Application` | Application |
+| `Volo.Abp.LowCode.HttpApi` | HttpApi |
+| `Volo.Abp.LowCode.HttpApi.Client` | HttpApi.Client |
+| `Volo.Abp.LowCode.EntityFrameworkCore` | EF Core |
+| `Volo.Abp.LowCode.Blazor` | Blazor UI (SSR) |
+| `Volo.Abp.LowCode.Blazor.Server` | Blazor Server |
+| `Volo.Abp.LowCode.Blazor.WebAssembly` | Blazor WebAssembly |
+| `Volo.Abp.LowCode.Installer` | Auto module discovery |
+
+### 2. Add Module Dependencies
+
+````csharp
+[DependsOn(
+    typeof(AbpLowCodeApplicationModule),
+    typeof(AbpLowCodeEntityFrameworkCoreModule),
+    typeof(AbpLowCodeHttpApiModule),
+    typeof(AbpLowCodeBlazorModule)
+)]
+public class YourModule : AbpModule
+{
+}
+````
+
+### 3. Register Your Assembly
+
+In your Domain module, register the assembly that contains your `[DynamicEntity]` classes:
+
+````csharp
+public override void ConfigureServices(ServiceConfigurationContext context)
+{
+    AbpDynamicEntityConfig.SourceAssemblies.Add(
+        new DynamicEntityAssemblyInfo(typeof(YourDomainModule).Assembly)
+    );
+}
+````
+
+### 4. Configure DbContext
+
+Call `ConfigureDynamicEntities()` in your `DbContext`:
+
+````csharp
+protected override void OnModelCreating(ModelBuilder builder)
+{
+    base.OnModelCreating(builder);
+    builder.ConfigureDynamicEntities();
+}
+````
+
+### 5. Define Your First Entity
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Customers")]
+public class Customer
+{
+    public string Name { get; set; }
+
+    [DynamicPropertyUI(DisplayName = "Phone Number")]
+    public string Telephone { get; set; }
+
+    [DynamicForeignKey("Volo.Abp.Identity.IdentityUser", "UserName")]
+    public Guid? UserId { get; set; }
+}
+````
+
+### 6. Add Migration and Run
+
+```bash
+dotnet ef migrations add Added_Customer
+dotnet ef database update
+```
+
+Start your application — the Customer page is ready.
+
+## Two Ways to Define Entities
+
+### C# Attributes (Recommended)
+
+Define entities as C# classes with attributes. You get compile-time checking, IntelliSense, and refactoring support:
+
+````csharp
+[DynamicEntity]
+[DynamicEntityUI(PageTitle = "Orders")]
+public class Order
+{
+    [DynamicForeignKey("MyApp.Customers.Customer", "Name", ForeignAccess.Edit)]
+    public Guid CustomerId { get; set; }
+
+    public decimal TotalAmount { get; set; }
+    public bool IsDelivered { get; set; }
+}
+
+[DynamicEntity(Parent = "MyApp.Orders.Order")]
+public class OrderLine
+{
+    [DynamicForeignKey("MyApp.Products.Product", "Name")]
+    public Guid ProductId { get; set; }
+
+    public int Quantity { get; set; }
+    public decimal Amount { get; set; }
+}
+````
+
+See [Fluent API & Attributes](fluent-api.md) for the full attribute reference.
+
+### model.json (Declarative)
+
+Alternatively, define entities in a JSON file without writing C# classes:
+
+```json
+{
+  "entities": [
+    {
+      "name": "MyApp.Customers.Customer",
+      "displayProperty": "Name",
+      "properties": [
+        { "name": "Name", "isRequired": true },
+        { "name": "Telephone", "ui": { "displayName": "Phone Number" } }
+      ],
+      "ui": { "pageTitle": "Customers" }
+    }
+  ]
+}
+```
+
+See [model.json Structure](model-json.md) for the full specification.
+
+> Both approaches can be combined. The [three-layer configuration system](fluent-api.md#configuration-priority) merges Attributes, JSON, and Fluent API with clear priority rules.
+
+## Key Features
+
+| Feature | Description | Documentation |
+|---------|-------------|---------------|
+| **Attributes & Fluent API** | Define entities with C# attributes and configure programmatically | [Fluent API & Attributes](fluent-api.md) |
+| **model.json** | Declarative entity definitions in JSON | [model.json Structure](model-json.md) |
+| **Reference Entities** | Link to existing entities like `IdentityUser` | [Reference Entities](reference-entities.md) |
+| **Interceptors** | Pre/Post hooks for Create, Update, Delete with JavaScript | [Interceptors](interceptors.md) |
+| **Scripting API** | Server-side JavaScript for database queries and CRUD | [Scripting API](scripting-api.md) |
+| **Custom Endpoints** | REST APIs with JavaScript handlers | [Custom Endpoints](custom-endpoints.md) |
+| **Foreign Access** | View/Edit related entities from the parent's UI | [Foreign Access](foreign-access.md) |
+
+## Internals
+
+### Domain Layer
+
+* `DynamicModelManager`: Singleton managing all entity metadata with a layered configuration architecture (Code > JSON > Fluent > Defaults).
+* `EntityDescriptor`: Entity definition with properties, foreign keys, interceptors, and UI configuration.
+* `EntityPropertyDescriptor`: Property definition with type, validation, UI settings, and foreign key info.
+* `IDynamicEntityRepository`: Repository for dynamic entity CRUD operations.
+
+### Application Layer
+
+* `DynamicEntityAppService`: CRUD operations for all dynamic entities.
+* `DynamicEntityUIAppService`: UI definitions, menu items, and page configurations.
+* `DynamicPermissionDefinitionProvider`: Auto-generates permissions per entity.
+* `CustomEndpointExecutor`: Executes JavaScript-based custom endpoints.
+
+### Database Providers
+
+**Entity Framework Core**: Dynamic entities are configured as EF Core [shared-type entities](https://learn.microsoft.com/en-us/ef/core/modeling/entity-types?tabs=fluent-api#shared-type-entity-types) via the `ConfigureDynamicEntities()` extension method.
+
+## See Also
+
+* [Fluent API & Attributes](fluent-api.md)
+* [model.json Structure](model-json.md)
+* [Scripting API](scripting-api.md)

docs/en/low-code/interceptors.md

@@ -0,0 +1,183 @@
+```json
+//[doc-seo]
+{
+    "Description": "Add custom business logic to dynamic entity CRUD operations using Interceptors in the ABP Low-Code Module. Validate, transform, and react to data changes with JavaScript."
+}
+```
+
+# Interceptors
+
+Interceptors allow you to run custom JavaScript code before or after Create, Update, and Delete operations on dynamic entities.
+
+## Interceptor Types
+
+| Command | Type | When Executed |
+|---------|------|---------------|
+| `Create` | `Pre` | Before entity creation — validation, default values |
+| `Create` | `Post` | After entity creation — notifications, related data |
+| `Update` | `Pre` | Before entity update — validation, authorization |
+| `Update` | `Post` | After entity update — sync, notifications |
+| `Delete` | `Pre` | Before entity deletion — dependency checks |
+| `Delete` | `Post` | After entity deletion — cleanup |
+
+## Defining Interceptors with Attributes
+
+Use the `[DynamicEntityCommandInterceptor]` attribute on a C# class:
+
+````csharp
+[DynamicEntity]
+[DynamicEntityCommandInterceptor(
+    "Create",
+    InterceptorType.Pre,
+    "if(!context.commandArgs.data['Name']) { globalError = 'Name is required!'; }"
+)]
+[DynamicEntityCommandInterceptor(
+    "Create",
+    InterceptorType.Post,
+    "context.log('Entity created: ' + context.commandArgs.entityId);"
+)]
+public class Organization
+{
+    public string Name { get; set; }
+}
+````
+
+The `Name` parameter must be one of: `"Create"`, `"Update"`, or `"Delete"`. This maps directly to the CRUD command being intercepted. Multiple interceptors can be added to the same class (`AllowMultiple = true`).
+
+## Defining Interceptors in model.json
+
+Add interceptors to the `interceptors` array of an entity:
+
+```json
+{
+  "name": "LowCodeDemo.Customers.Customer",
+  "interceptors": [
+    {
+      "commandName": "Create",
+      "type": "Pre",
+      "javascript": "if(context.commandArgs.data['Name'] == 'Invalid') {\n  globalError = 'Invalid Customer Name!';\n}"
+    }
+  ]
+}
+```
+
+### Interceptor Descriptor
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `commandName` | string | `"Create"`, `"Update"`, or `"Delete"` |
+| `type` | string | `"Pre"` or `"Post"` |
+| `javascript` | string | JavaScript code to execute |
+
+## JavaScript Context
+
+Inside interceptor scripts, you have access to:
+
+### `context.commandArgs`
+
+| Property | Type | Description |
+|----------|------|-------------|
+| `data` | object | Entity data dictionary (for Create/Update) |
+| `entityId` | string | Entity ID (for Update/Delete) |
+| `getValue(name)` | function | Get a property value |
+| `setValue(name, value)` | function | Set a property value (Pre-interceptors only) |
+
+### `context.currentUser`
+
+| Property | Type | Description |
+|----------|------|-------------|
+| `isAuthenticated` | bool | Whether user is logged in |
+| `userName` | string | Username |
+| `email` | string | Email address |
+| `roles` | string[] | User's role names |
+| `id` | string | User ID |
+
+### `context.emailSender`
+
+| Method | Description |
+|--------|-------------|
+| `sendAsync(to, subject, body)` | Send an email |
+
+### `context.log(message)`
+
+Log a message (use instead of `console.log`).
+
+### `db` (Database API)
+
+Full access to the [Scripting API](scripting-api.md) for querying and mutating data.
+
+### `globalError`
+
+Set this variable to a string to **abort** the operation and return an error:
+
+```javascript
+globalError = 'Cannot delete this entity!';
+```
+
+## Examples
+
+### Pre-Create: Validation
+
+```json
+{
+  "commandName": "Create",
+  "type": "Pre",
+  "javascript": "if(!context.commandArgs.data['Name']) {\n  globalError = 'Organization name is required!';\n}"
+}
+```
+
+### Post-Create: Email Notification
+
+```json
+{
+  "commandName": "Create",
+  "type": "Post",
+  "javascript": "if(context.currentUser.isAuthenticated && context.emailSender) {\n  await context.emailSender.sendAsync(\n    context.currentUser.email,\n    'New Order Created',\n    'Order total: $' + context.commandArgs.data['TotalAmount']\n  );\n}"
+}
+```
+
+### Pre-Update: Role-Based Authorization
+
+```json
+{
+  "commandName": "Update",
+  "type": "Pre",
+  "javascript": "if(context.commandArgs.data['IsDelivered']) {\n  if(!context.currentUser.roles.includes('admin')) {\n    globalError = 'Only administrators can mark orders as delivered!';\n  }\n}"
+}
+```
+
+### Pre-Delete: Business Rule Check
+
+```json
+{
+  "commandName": "Delete",
+  "type": "Pre",
+  "javascript": "var project = await db.get('LowCodeDemo.Projects.Project', context.commandArgs.entityId);\nif(project.Budget > 100000) {\n  globalError = 'Cannot delete high-budget projects!';\n}"
+}
+```
+
+### Pre-Update: Negative Value Check
+
+```json
+{
+  "commandName": "Update",
+  "type": "Pre",
+  "javascript": "if(context.commandArgs.data['Quantity'] < 0) {\n  globalError = 'Quantity cannot be negative!';\n}"
+}
+```
+
+### Pre-Create: Self-Reference Check
+
+```json
+{
+  "commandName": "Update",
+  "type": "Pre",
+  "javascript": "if(context.commandArgs.data.ParentCategoryId === context.commandArgs.entityId) {\n  globalError = 'A category cannot be its own parent!';\n}"
+}
+```
+
+## See Also
+
+* [Scripting API](scripting-api.md)
+* [model.json Structure](model-json.md)
+* [Custom Endpoints](custom-endpoints.md)

docs/en/low-code/model-json.md

@@ -0,0 +1,382 @@
+```json
+//[doc-seo]
+{
+    "Description": "Define dynamic entities using model.json in the ABP Low-Code Module. Learn about entity properties, enums, foreign keys, validators, UI configuration, and migration requirements."
+}
+```
+
+# model.json Structure
+
+The `model.json` file defines all your dynamic entities, their properties, enums, relationships, interceptors, custom endpoints, and UI configurations. It is an alternative configuration source to [C# Attributes and Fluent API](fluent-api.md), ideal when you prefer a declarative JSON approach.
+
+## File Location
+
+Place your `model.json` in a `_Dynamic` folder inside your **Domain** project:
+
+```
+YourApp.Domain/
+└── _Dynamic/
+    └── model.json
+```
+
+The module automatically discovers and loads this file at application startup.
+
+> A JSON Schema file (`model.schema.json`) is available in the module source for IDE IntelliSense. Reference it using the `$schema` property:
+
+```json
+{
+  "$schema": "path/to/model.schema.json",
+  "entities": []
+}
+```
+
+## Top-Level Structure
+
+The `model.json` file has three root sections:
+
+```json
+{
+  "$schema": "...",
+  "enums": [],
+  "entities": [],
+  "endpoints": []
+}
+```
+
+| Section | Description |
+|---------|-------------|
+| `enums` | Enum type definitions |
+| `entities` | Entity definitions with properties, foreign keys, interceptors, and UI |
+| `endpoints` | Custom REST API endpoints with JavaScript handlers |
+
+## Enum Definitions
+
+Define enums that can be used as property types:
+
+```json
+{
+  "enums": [
+    {
+      "name": "LowCodeDemo.Organizations.OrganizationType",
+      "values": [
+        { "name": "Corporate", "value": 0 },
+        { "name": "Enterprise", "value": 1 },
+        { "name": "Startup", "value": 2 },
+        { "name": "Consulting", "value": 3 }
+      ]
+    }
+  ]
+}
+```
+
+Reference enums in entity properties using the `enumType` field:
+
+```json
+{
+  "name": "OrganizationType",
+  "enumType": "LowCodeDemo.Organizations.OrganizationType"
+}
+```
+
+## Entity Definition
+
+Each entity has the following structure:
+
+```json
+{
+  "name": "LowCodeDemo.Products.Product",
+  "displayProperty": "Name",
+  "parent": null,
+  "properties": [],
+  "foreignKeys": [],
+  "interceptors": [],
+  "ui": {}
+}
+```
+
+### Entity Attributes
+
+| Attribute | Type | Description |
+|-----------|------|-------------|
+| `name` | string | **Required.** Full entity name with namespace (e.g., `"MyApp.Products.Product"`) |
+| `displayProperty` | string | Property to display in lookups and foreign key dropdowns |
+| `parent` | string | Parent entity name for parent-child (master-detail) relationships |
+| `properties` | array | Property definitions |
+| `interceptors` | array | CRUD lifecycle interceptors |
+| `ui` | object | UI configuration |
+
+### Parent-Child Relationships
+
+Use the `parent` field to create nested entities. Children are managed through the parent entity's UI:
+
+```json
+{
+  "name": "LowCodeDemo.Orders.OrderLine",
+  "parent": "LowCodeDemo.Orders.Order",
+  "properties": [
+    {
+      "name": "ProductId",
+      "foreignKey": {
+        "entityName": "LowCodeDemo.Products.Product"
+      }
+    },
+    { "name": "Quantity", "type": "int" },
+    { "name": "Amount", "type": "decimal" }
+  ]
+}
+```
+
+Multi-level nesting is supported (e.g., `Order > OrderLine > ShipmentItem > ShipmentTracking`).
+
+## Property Definition
+
+```json
+{
+  "name": "Price",
+  "type": "decimal",
+  "isRequired": true,
+  "isUnique": false,
+  "isMappedToDbField": true,
+  "serverOnly": false,
+  "allowSetByClients": true,
+  "enumType": null,
+  "foreignKey": null,
+  "validators": [],
+  "ui": {}
+}
+```
+
+### Property Types
+
+| Type | Description |
+|------|-------------|
+| `string` | Text (default if type is omitted) |
+| `int` | 32-bit integer |
+| `long` | 64-bit integer |
+| `decimal` | Decimal number |
+| `DateTime` | Date and time |
+| `boolean` | True/false |
+| `Guid` | GUID/UUID |
+| `Enum` | Enum type (requires `enumType` field) |
+
+### Property Flags
+
+| Flag | Type | Default | Description |
+|------|------|---------|-------------|
+| `isRequired` | bool | `false` | Property must have a value |
+| `isUnique` | bool | `false` | Value must be unique across all records |
+| `isMappedToDbField` | bool | `true` | Property is stored in the database |
+| `serverOnly` | bool | `false` | Property is hidden from API clients |
+| `allowSetByClients` | bool | `true` | Whether clients can set this value |
+
+### Foreign Key Properties
+
+Define a foreign key relationship inline on a property:
+
+```json
+{
+  "name": "CustomerId",
+  "foreignKey": {
+    "entityName": "LowCodeDemo.Customers.Customer",
+    "displayPropertyName": "Name",
+    "access": "edit"
+  }
+}
+```
+
+| Attribute | Description |
+|-----------|-------------|
+| `entityName` | **Required.** Full name of the referenced entity |
+| `displayPropertyName` | Property to display in lookups (defaults to entity's `displayProperty`) |
+| `access` | [Foreign access](foreign-access.md) level: `"none"`, `"view"`, or `"edit"` |
+
+### Validators
+
+Add validation rules to properties:
+
+```json
+{
+  "name": "EmailAddress",
+  "validators": [
+    { "type": "required" },
+    { "type": "emailAddress" },
+    { "type": "minLength", "length": 5 },
+    { "type": "maxLength", "length": 255 }
+  ]
+}
+```
+
+| Validator | Parameters | Description |
+|-----------|------------|-------------|
+| `required` | — | Value is required |
+| `minLength` | `length` | Minimum string length |
+| `maxLength` | `length` | Maximum string length |
+| `emailAddress` | — | Must be a valid email |
+| `range` | `min`, `max` | Numeric range |
+
+## UI Configuration
+
+### Entity-Level UI
+
+```json
+{
+  "ui": {
+    "pageTitle": "Products"
+  }
+}
+```
+
+> Only entities with `ui.pageTitle` get a menu item and a dedicated page in the UI.
+
+### Property-Level UI
+
+```json
+{
+  "name": "RegistrationNumber",
+  "ui": {
+    "displayName": "Registration Number",
+    "isAvailableOnDataTable": true,
+    "isAvailableOnDataTableFiltering": true,
+    "creationFormAvailability": "Hidden",
+    "editingFormAvailability": "NotAvailable",
+    "quickLookOrder": 100
+  }
+}
+```
+
+| Attribute | Type | Default | Description |
+|-----------|------|---------|-------------|
+| `displayName` | string | Property name | Display label in UI |
+| `isAvailableOnDataTable` | bool | `true` | Show in data grid |
+| `isAvailableOnDataTableFiltering` | bool | `true` | Show in filter panel |
+| `creationFormAvailability` | string | `"Available"` | Visibility in create form |
+| `editingFormAvailability` | string | `"Available"` | Visibility in edit form |
+| `quickLookOrder` | int | -2 | Order in quick-look panel (-2 = not shown) |
+
+#### Form Availability Values
+
+| Value | Description |
+|-------|-------------|
+| `Available` | Visible and editable |
+| `Hidden` | Not visible in the form |
+| `NotAvailable` | Visible but disabled/read-only |
+
+## Interceptors
+
+Define JavaScript interceptors for CRUD lifecycle hooks:
+
+```json
+{
+  "interceptors": [
+    {
+      "commandName": "Create",
+      "type": "Pre",
+      "javascript": "if(!context.commandArgs.data['Name']) { globalError = 'Name is required!'; }"
+    }
+  ]
+}
+```
+
+See [Interceptors](interceptors.md) for details.
+
+## Endpoints
+
+Define custom REST endpoints with JavaScript handlers:
+
+```json
+{
+  "endpoints": [
+    {
+      "name": "GetProductStats",
+      "route": "/api/custom/products/stats",
+      "method": "GET",
+      "requireAuthentication": false,
+      "javascript": "var count = await db.count('Products.Product'); return ok({ total: count });"
+    }
+  ]
+}
+```
+
+See [Custom Endpoints](custom-endpoints.md) for details.
+
+## Complete Example
+
+```json
+{
+  "enums": [
+    {
+      "name": "ShipmentStatus",
+      "values": [
+        { "name": "Pending", "value": 0 },
+        { "name": "Shipped", "value": 2 },
+        { "name": "Delivered", "value": 4 }
+      ]
+    }
+  ],
+  "entities": [
+    {
+      "name": "LowCodeDemo.Products.Product",
+      "displayProperty": "Name",
+      "properties": [
+        { "name": "Name", "isUnique": true, "isRequired": true },
+        { "name": "Price", "type": "decimal" },
+        { "name": "StockCount", "type": "int" },
+        { "name": "ReleaseDate", "type": "DateTime" }
+      ],
+      "ui": { "pageTitle": "Products" }
+    },
+    {
+      "name": "LowCodeDemo.Orders.Order",
+      "displayProperty": "Id",
+      "properties": [
+        {
+          "name": "CustomerId",
+          "foreignKey": {
+            "entityName": "LowCodeDemo.Customers.Customer",
+            "access": "edit"
+          }
+        },
+        { "name": "TotalAmount", "type": "decimal" },
+        { "name": "IsDelivered", "type": "boolean" }
+      ],
+      "interceptors": [
+        {
+          "commandName": "Create",
+          "type": "Post",
+          "javascript": "context.log('Order created: ' + context.commandArgs.entityId);"
+        }
+      ],
+      "ui": { "pageTitle": "Orders" }
+    },
+    {
+      "name": "LowCodeDemo.Orders.OrderLine",
+      "parent": "LowCodeDemo.Orders.Order",
+      "properties": [
+        {
+          "name": "ProductId",
+          "foreignKey": { "entityName": "LowCodeDemo.Products.Product" }
+        },
+        { "name": "Quantity", "type": "int" },
+        { "name": "Amount", "type": "decimal" }
+      ]
+    }
+  ]
+}
+```
+
+## Migration Requirements
+
+When you modify `model.json`, you need database migrations for the changes to take effect:
+
+* **New entity**: `dotnet ef migrations add Added_{EntityName}`
+* **New property**: `dotnet ef migrations add Added_{PropertyName}_To_{EntityName}`
+* **Type change**: `dotnet ef migrations add Changed_{PropertyName}_In_{EntityName}`
+
+> The same migration requirement applies when using [C# Attributes](fluent-api.md). Any change to entity structure requires an EF Core migration.
+
+## See Also
+
+* [Fluent API & Attributes](fluent-api.md)
+* [Interceptors](interceptors.md)
+* [Custom Endpoints](custom-endpoints.md)
+* [Scripting API](scripting-api.md)

docs/en/low-code/reference-entities.md

@@ -0,0 +1,128 @@
+```json
+//[doc-seo]
+{
+    "Description": "Link dynamic entities to existing C# entities like IdentityUser using Reference Entities in the ABP Low-Code Module."
+}
+```
+
+# Reference Entities
+
+Reference Entities allow you to create foreign key relationships from dynamic entities to **existing (static) C# entities** that are already defined in your application or in ABP modules.
+
+## Overview
+
+Dynamic entities defined via [Attributes](fluent-api.md) or [model.json](model-json.md) normally reference other dynamic entities. However, you may need to link to entities like ABP's `IdentityUser`, `Tenant`, or your own C# entity classes. Reference entities make this possible.
+
+Unlike dynamic entities, reference entities are **read-only** from the Low-Code Module's perspective — they don't get CRUD pages or APIs. They are used solely for:
+
+* **Foreign key lookups** — dropdown selection in UI forms
+* **Display values** — showing the referenced entity's display property in grids
+* **Query support** — querying via the [Scripting API](scripting-api.md)
+
+## Registering Reference Entities
+
+Register reference entities in your Domain module's `ConfigureServices` using `AbpDynamicEntityConfig.ReferencedEntityList`:
+
+````csharp
+public override void ConfigureServices(ServiceConfigurationContext context)
+{
+    AbpDynamicEntityConfig.ReferencedEntityList.Add<IdentityUser>(
+        "UserName"        // Default display property
+    );
+
+    AbpDynamicEntityConfig.ReferencedEntityList.Add<IdentityUser>(
+        "UserName",       // Default display property
+        "UserName",       // Exposed properties
+        "Email",
+        "PhoneNumber"
+    );
+}
+````
+
+### `Add<TEntity>` Method
+
+````csharp
+public void Add<TEntity>(
+    string defaultDisplayProperty,
+    params string[] properties
+) where TEntity : class, IEntity<Guid>
+````
+
+| Parameter | Description |
+|-----------|-------------|
+| `defaultDisplayProperty` | Property name used as display value in lookups |
+| `properties` | Additional properties to expose (optional) |
+
+> The entity type must implement `IEntity<Guid>`.
+
+## Using Reference Entities in model.json
+
+Reference a registered entity in a foreign key definition:
+
+```json
+{
+  "name": "UserId",
+  "foreignKey": {
+    "entityName": "Volo.Abp.Identity.IdentityUser"
+  }
+}
+```
+
+The entity name must match the CLR type's full name. The module automatically detects that this is a reference entity and uses the registered `ReferenceEntityDescriptor`.
+
+## Using Reference Entities with Attributes
+
+Use the `[DynamicForeignKey]` attribute on a Guid property:
+
+````csharp
+[DynamicEntity]
+public class Customer
+{
+    [DynamicForeignKey("Volo.Abp.Identity.IdentityUser", "UserName")]
+    public Guid? UserId { get; set; }
+}
+````
+
+## How It Works
+
+The `ReferenceEntityDescriptor` class stores metadata about the reference entity:
+
+* `Name` — Full CLR type name
+* `Type` — The actual CLR type
+* `DefaultDisplayPropertyName` — Display property for lookups
+* `Properties` — List of `ReferenceEntityPropertyDescriptor` entries
+
+When a foreign key points to a reference entity, the `ForeignKeyDescriptor` populates its `ReferencedEntityDescriptor` and `ReferencedDisplayPropertyDescriptor` instead of the standard `EntityDescriptor` fields.
+
+## Querying Reference Entities in Scripts
+
+Reference entities can be queried via the [Scripting API](scripting-api.md):
+
+```javascript
+// Query reference entity in interceptor or custom endpoint
+var user = await db.get('Volo.Abp.Identity.IdentityUser', userId);
+if (user) {
+    context.log('User: ' + user.UserName);
+}
+```
+
+## Limitations
+
+* **Read-only**: Reference entities do not get CRUD operations, permissions, or UI pages.
+* **No child entities**: You cannot define a reference entity as a parent in parent-child relationships.
+* **Guid keys only**: Reference entities must have `Guid` primary keys (`IEntity<Guid>`).
+* **Explicit registration required**: Each reference entity must be registered in code before use.
+
+## Common Reference Entities
+
+| Entity | Name for `entityName` | Typical Display Property |
+|--------|----------------------|--------------------------|
+| ABP Identity User | `Volo.Abp.Identity.IdentityUser` | `UserName` |
+| ABP Identity Role | `Volo.Abp.Identity.IdentityRole` | `Name` |
+| ABP Tenant | `Volo.Saas.Tenant` | `Name` |
+
+## See Also
+
+* [model.json Structure](model-json.md)
+* [Foreign Access](foreign-access.md)
+* [Fluent API & Attributes](fluent-api.md)

docs/en/low-code/scripting-api.md

@@ -0,0 +1,428 @@
+```json
+//[doc-seo]
+{
+    "Description": "Server-side JavaScript Scripting API for ABP Low-Code Module. Query, filter, aggregate data and perform CRUD operations with database-level execution."
+}
+```
+
+# Scripting API
+
+The Low-Code Module provides a server-side JavaScript scripting engine for executing custom business logic within [interceptors](interceptors.md) and [custom endpoints](custom-endpoints.md). Scripts run in a sandboxed environment with access to a database API backed by EF Core.
+
+## Unified Database API (`db`)
+
+The `db` object is the main entry point for all data operations.
+
+### Key Design Principles
+
+* **Immutable Query Builder** — each query method returns a new builder instance. The original is never modified.
+* **Database-Level Execution** — all operations (filters, aggregations, joins, set operations) translate to SQL via EF Core and Dynamic LINQ.
+* **No in-memory processing** of large datasets.
+
+```javascript
+// Immutable pattern — each call creates a new builder
+var baseQuery = db.query('Entity').where(x => x.Active);
+var cheap = baseQuery.where(x => x.Price < 100);     // baseQuery unchanged
+var expensive = baseQuery.where(x => x.Price > 500);  // baseQuery unchanged
+```
+
+## Query API
+
+### Basic Queries
+
+```javascript
+var products = await db.query('LowCodeDemo.Products.Product')
+    .where(x => x.Price > 100)
+    .orderBy(x => x.Price)
+    .take(10)
+    .toList();
+
+var result = await db.query('LowCodeDemo.Products.Product')
+    .where(x => x.Price > 100 && x.Price < 500)
+    .where(x => x.StockCount > 0)
+    .orderByDescending(x => x.Price)
+    .skip(10)
+    .take(20)
+    .toList();
+```
+
+### Query Methods
+
+| Method | Description | Returns |
+|--------|-------------|---------|
+| `where(x => condition)` | Filter results | `QueryBuilder` |
+| `orderBy(x => x.Property)` | Sort ascending | `QueryBuilder` |
+| `orderByDescending(x => x.Property)` | Sort descending | `QueryBuilder` |
+| `thenBy(x => x.Property)` | Secondary sort ascending | `QueryBuilder` |
+| `thenByDescending(x => x.Property)` | Secondary sort descending | `QueryBuilder` |
+| `skip(n)` | Skip n records | `QueryBuilder` |
+| `take(n)` | Take n records | `QueryBuilder` |
+| `reverse()` | Reverse sort order | `QueryBuilder` |
+| `toList()` | Execute and return array | `Promise<object[]>` |
+| `count()` | Return count | `Promise<number>` |
+| `any()` | Check if any matches exist | `Promise<boolean>` |
+| `all(x => condition)` | Check if all records match | `Promise<boolean>` |
+| `isEmpty()` | Check if no results | `Promise<boolean>` |
+| `isSingle()` | Check if exactly one result | `Promise<boolean>` |
+| `first()` / `firstOrDefault()` | Return first match or null | `Promise<object\|null>` |
+| `last()` / `lastOrDefault()` | Return last match or null | `Promise<object\|null>` |
+| `single()` / `singleOrDefault()` | Return single match or null | `Promise<object\|null>` |
+| `elementAt(index)` | Return element at index | `Promise<object\|null>` |
+| `select(x => projection)` | Project to custom shape | `QueryBuilder` |
+| `join(entity, alias, condition)` | Inner join | `QueryBuilder` |
+| `leftJoin(entity, alias, condition)` | Left join | `QueryBuilder` |
+| `chunk(size)` | Split into chunks | `Promise<object[][]>` |
+
+### Supported Operators in Lambda
+
+| Category | Operators |
+|----------|-----------|
+| Comparison | `===`, `!==`, `>`, `>=`, `<`, `<=` |
+| Logical | `&&`, `\|\|`, `!` |
+| Arithmetic | `+`, `-`, `*`, `/`, `%` |
+| String | `startsWith()`, `endsWith()`, `includes()`, `trim()`, `toLowerCase()`, `toUpperCase()` |
+| Array | `array.includes(x.Property)` — translates to SQL `IN` |
+| Math | `Math.round()`, `Math.floor()`, `Math.ceil()`, `Math.abs()`, `Math.sqrt()`, `Math.pow()`, `Math.sign()`, `Math.truncate()` |
+| Null | `!= null`, `=== null` |
+
+### Variable Capture
+
+External variables are captured and passed as parameters:
+
+```javascript
+var minPrice = 100;
+var config = { minStock: 10 };
+var nested = { range: { min: 50, max: 200 } };
+
+var result = await db.query('Entity').where(x => x.Price > minPrice).toList();
+var result2 = await db.query('Entity').where(x => x.StockCount > config.minStock).toList();
+var result3 = await db.query('Entity').where(x => x.Price >= nested.range.min).toList();
+```
+
+### Contains / IN Operator
+
+```javascript
+var targetPrices = [50, 100, 200];
+var products = await db.query('Entity')
+    .where(x => targetPrices.includes(x.Price))
+    .toList();
+```
+
+### Select Projection
+
+```javascript
+var projected = await db.query('LowCodeDemo.Products.Product')
+    .where(x => x.Price > 0)
+    .select(x => ({ ProductName: x.Name, ProductPrice: x.Price }))
+    .toList();
+```
+
+## Joins
+
+### Explicit Joins
+
+```javascript
+var orderLines = await db.query('LowCodeDemo.Orders.OrderLine')
+    .join('LowCodeDemo.Products.Product', 'p', (ol, p) => ol.ProductId === p.Id)
+    .take(10)
+    .toList();
+
+// Access joined data via alias
+orderLines.forEach(line => {
+    var product = line.p;
+    context.log(product.Name + ': $' + line.Amount);
+});
+```
+
+### Left Join
+
+```javascript
+var orders = await db.query('LowCodeDemo.Orders.Order')
+    .leftJoin('LowCodeDemo.Products.Product', 'p', (o, p) => o.CustomerId === p.Id)
+    .toList();
+
+orders.forEach(order => {
+    if (order.p) {
+        context.log('Has match: ' + order.p.Name);
+    }
+});
+```
+
+### LINQ-Style Join
+
+```javascript
+db.query('Order')
+  .join('LowCodeDemo.Products.Product',
+        o => o.ProductId,
+        p => p.Id)
+```
+
+### Join with Filtered Query
+
+```javascript
+var expensiveProducts = db.query('Product').where(p => p.Price > 100);
+
+var orders = await db.query('OrderLine')
+  .join(expensiveProducts,
+        ol => ol.ProductId,
+        p => p.Id)
+  .toList();
+```
+
+## Set Operations
+
+Set operations execute at the database level using SQL:
+
+| Method | SQL Equivalent | Description |
+|--------|---------------|-------------|
+| `union(query)` | `UNION` | Combine, remove duplicates |
+| `concat(query)` | `UNION ALL` | Combine, keep duplicates |
+| `intersect(query)` | `INTERSECT` | Elements in both |
+| `except(query)` | `EXCEPT` | Elements in first, not second |
+
+```javascript
+var cheap = db.query('Product').where(x => x.Price <= 100);
+var popular = db.query('Product').where(x => x.Rating > 4);
+
+var bestDeals = await cheap.intersect(popular).toList();
+var underrated = await cheap.except(popular).toList();
+```
+
+## Aggregation Methods
+
+All aggregations execute as SQL statements:
+
+| Method | SQL | Returns |
+|--------|-----|---------|
+| `sum(x => x.Property)` | `SELECT SUM(...)` | `Promise<number>` |
+| `average(x => x.Property)` | `SELECT AVG(...)` | `Promise<number>` |
+| `min(x => x.Property)` | `SELECT MIN(...)` | `Promise<any>` |
+| `max(x => x.Property)` | `SELECT MAX(...)` | `Promise<any>` |
+| `distinct(x => x.Property)` | `SELECT DISTINCT ...` | `Promise<any[]>` |
+| `groupBy(x => x.Property)` | `GROUP BY ...` | `Promise<GroupResult[]>` |
+
+```javascript
+var totalValue = await db.query('Product').sum(x => x.Price);
+var avgPrice = await db.query('Product').where(x => x.InStock).average(x => x.Price);
+var cheapest = await db.query('Product').min(x => x.Price);
+```
+
+### GroupBy with Select
+
+```javascript
+var grouped = await db.query('Product')
+    .groupBy(x => x.Category)
+    .select(g => ({
+        Category: g.Key,
+        Count: g.count(),
+        TotalPrice: g.sum(x => x.Price),
+        AvgPrice: g.average(x => x.Price),
+        MinPrice: g.min(x => x.Price),
+        MaxPrice: g.max(x => x.Price)
+    }))
+    .toList();
+```
+
+### GroupBy Aggregation Methods
+
+| Method | SQL |
+|--------|-----|
+| `g.Key` | Group key value |
+| `g.count()` | `COUNT(*)` |
+| `g.sum(x => x.Prop)` | `SUM(prop)` |
+| `g.average(x => x.Prop)` | `AVG(prop)` |
+| `g.min(x => x.Prop)` | `MIN(prop)` |
+| `g.max(x => x.Prop)` | `MAX(prop)` |
+| `g.toList()` | Get group items |
+| `g.take(n).toList()` | Get first n items |
+
+### GroupBy with Items
+
+```javascript
+var grouped = await db.query('Product')
+    .groupBy(x => x.Category)
+    .select(g => ({
+        Category: g.Key,
+        Count: g.count(),
+        Items: g.take(10).toList()
+    }))
+    .toList();
+```
+
+### GroupBy Security Limits
+
+| Limit | Default | Description |
+|-------|---------|-------------|
+| `MaxGroupCount` | 100 | Maximum groups |
+| `MaxItemsPerGroup` | 50 | Items per group |
+| `MaxTotalGroupedItems` | 1000 | Total items across groups |
+
+## Math Functions
+
+Math functions translate to SQL functions (ROUND, FLOOR, CEILING, ABS, etc.):
+
+```javascript
+var products = await db.query('Product')
+    .where(x => Math.round(x.Price) > 100)
+    .toList();
+
+var result = await db.query('Product')
+    .where(x => Math.abs(x.Balance) < 10 && Math.floor(x.Rating) >= 4)
+    .toList();
+```
+
+## CRUD API
+
+Direct CRUD methods on the `db` object:
+
+| Method | Description | Returns |
+|--------|-------------|---------|
+| `db.get(entityName, id)` | Get by ID | `Promise<object\|null>` |
+| `db.getList(entityName, take?)` | Get list | `Promise<object[]>` |
+| `db.getCount(entityName)` | Get count | `Promise<number>` |
+| `db.insert(entityName, entity)` | Insert new | `Promise<object>` |
+| `db.update(entityName, entity)` | Update existing | `Promise<object>` |
+| `db.delete(entityName, id)` | Delete by ID | `Promise<void>` |
+
+```javascript
+// Get by ID
+var product = await db.get('LowCodeDemo.Products.Product', id);
+
+// Insert
+var newProduct = await db.insert('LowCodeDemo.Products.Product', {
+    Name: 'New Product',
+    Price: 99.99,
+    StockCount: 100
+});
+
+// Update
+var updated = await db.update('LowCodeDemo.Products.Product', {
+    Id: existingId,
+    Name: 'Updated Name',
+    Price: 149.99
+});
+
+// Delete
+await db.delete('LowCodeDemo.Products.Product', id);
+```
+
+## Context Object
+
+Available in [interceptors](interceptors.md):
+
+| Property | Type | Description |
+|----------|------|-------------|
+| `context.commandArgs` | object | Command arguments (data, entityId) |
+| `context.commandArgs.getValue(name)` | function | Get property value |
+| `context.commandArgs.setValue(name, value)` | function | Set property value |
+| `context.currentUser` | object | Current user (isAuthenticated, userName, email, roles, id) |
+| `context.emailSender` | object | Email sending (`sendAsync(to, subject, body)`) |
+| `context.log(msg)` | function | Logging |
+
+## Security
+
+### Sandbox Constraints
+
+| Constraint | Default | Configurable |
+|------------|---------|--------------|
+| Script Timeout | 10 seconds | Yes |
+| Max Statements | 10,000 | Yes |
+| Memory Limit | 10 MB | Yes |
+| Recursion Depth | 100 levels | Yes |
+| CLR Access | Disabled | No |
+
+### Query Security Limits
+
+| Limit | Default | Description |
+|-------|---------|-------------|
+| MaxExpressionNodes | 100 | Max AST nodes per expression |
+| MaxExpressionDepth | 10 | Max nesting depth |
+| MaxNavigationDepth | 5 | Max navigation property depth |
+| MaxLimit (take) | 1000 | Max records per query |
+| DefaultLimit | 100 | Default if `take()` not specified |
+| MaxArraySize (includes) | 100 | Max array size for IN operations |
+
+### Property Whitelist
+
+Only properties defined in the entity model can be queried. Accessing undefined properties throws a `SecurityException`.
+
+### SQL Injection Protection
+
+All values are parameterized:
+
+```javascript
+var malicious = "'; DROP TABLE Products;--";
+// Safely treated as a literal string — no injection
+var result = await db.query('Entity').where(x => x.Name.includes(malicious)).count();
+```
+
+### Blocked Features
+
+The following are **not allowed** inside lambda expressions: `typeof`, `instanceof`, `in`, bitwise operators, `eval()`, `Function()`, `new RegExp()`, `new Date()`, `console.log()`, `setTimeout()`, `globalThis`, `window`, `__proto__`, `constructor`, `prototype`, `Reflect`, `Proxy`, `Symbol`.
+
+## Error Handling
+
+```javascript
+// Abort operation with error
+if (!context.commandArgs.getValue('Email').includes('@')) {
+    throw new Error('Valid email is required');
+}
+
+// Try-catch for safe execution
+try {
+    var products = await db.query('Entity').where(x => x.Price > 0).toList();
+} catch (error) {
+    context.log('Query failed: ' + error.message);
+}
+```
+
+## Best Practices
+
+1. **Use specific filters** — avoid querying all records without `where()`
+2. **Set limits** — always use `take()` to limit results
+3. **Validate early** — check inputs at the start of scripts
+4. **Use `first()` for single results** — instead of `toList()[0]`
+5. **Keep scripts focused** — one responsibility per interceptor
+6. **Use `context.log()`** — never `console.log()`
+7. **Handle nulls** — check for null before property access
+
+## Examples
+
+### Inventory Check on Order Creation
+
+```javascript
+// Pre-create interceptor for Order
+var productId = context.commandArgs.getValue('ProductId');
+var quantity = context.commandArgs.getValue('Quantity');
+
+var product = await db.query('LowCodeDemo.Products.Product')
+    .where(x => x.Id === productId)
+    .first();
+
+if (!product) { throw new Error('Product not found'); }
+if (product.StockCount < quantity) { throw new Error('Insufficient stock'); }
+
+context.commandArgs.setValue('TotalAmount', product.Price * quantity);
+```
+
+### Sales Dashboard (Custom Endpoint)
+
+```javascript
+var totalOrders = await db.query('LowCodeDemo.Orders.Order').count();
+var delivered = await db.query('LowCodeDemo.Orders.Order')
+    .where(x => x.IsDelivered === true).count();
+var revenue = await db.query('LowCodeDemo.Orders.Order')
+    .where(x => x.IsDelivered === true).sum(x => x.TotalAmount);
+
+return ok({
+    orders: totalOrders,
+    delivered: delivered,
+    revenue: revenue
+});
+```
+
+## See Also
+
+* [Interceptors](interceptors.md)
+* [Custom Endpoints](custom-endpoints.md)
+* [model.json Structure](model-json.md)