---
author_name: Sumana Vasuki
author_profile: https://github.com/Sumana-vasuki
parser: v2
auto_validation: true
time: 10
tags: [ tutorial>beginner, programming-tool>abap-development, programming-tool>abap-extensibility, tutorial>license]
primary_tag: software-product>sap-btp--abap-environment
slug: abap-environment-saas-mta-approuter
canonical_url: https://developers.sap.com/tutorials/abap-environment-saas-mta-approuter
---

# Develop and Configure an approuter application for the multitenant application of the SaaS solution

<!-- description --> Develop and configure the approuter application for the multitenant application of the solution

## Prerequisites

- You have created an MTA project for the Multitenant Application in the Business Application Studio as per the previous tutorial of this group

## You will learn

- How to configure an approuter application.

---

### Create a Node.js project for the router

To authenticate business users of the application at runtime, use the tenant-aware approuter application and the XSUAA service in SAP Business Technology Platform. This will also provide the necessary callbacks for the SaaS Provisioning Service. In addition, we provide the middleware `@sap/asp-middleware` component that enhances the approuter to also take care of automatically routing the consumer to their ABAP tenant.

   ![Provider Subaccount-MTA](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/providerMTA.jpg)

 1. Create a new folder called 'router'. This step happens in the Business Application Studio, in the project folder created in the previous tutorial

    ![New Folder](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/routerFolder.png)  
  
 2. Open a command prompt (terminal) in this folder

    ![Open in terminal](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/OpenInTerminal.png)

 3. Create a new project by executing the following command  

   ```Shell/Bash
   npm init
   ```

   In the upcoming wizard flow you can leave the defaults or define your own values if preferred

   ![NPM INIT](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/npmInit.png)

   Result: After the project is initialized, the package contains a package.json file  

   ![Package JSON](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/packageJSON.png)

 4. The `package.json` should have the following content (if the defaults are kept):  

 5. Replace your code
  
   ```JSON
   { 
     "name": "router",
     "version": "1.0.0",
     "description": "",
     "main": "index.js",
     "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
     },
     "author": "",
     "license": "ISC",
   } 
   ```

### Install necessary dependencies

The '@sap/approuter' and the '@sap/asp-middleware' must be installed so that they can be used in the start script.

 1. Execute the following command in the terminal:

   ```Shell/Bash
   npm install @sap/approuter @sap/asp-middleware 
   ```

   ![Install Dependencies](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/installDependencies.png)

 2. Result: The two modules will be listed in the package.json as 'dependencies' and are downloaded into the node\_modules folder.

    Updated package.json (versions might differ):

   ```JSON
   {
      "name": "router",
      "version": "1.0.0",
      "description": "",
      "main": "index.js",
      "scripts": {
      "test": "echo \"Error: no test specified\" && exit 1"
      },
      "author": "",
      "license": "ISC",
      "dependencies": {
      "@sap/approuter": "^11.2.1",
      "@sap/asp-middleware": "^1.0.9"
      }
   }
   ```

### Add a start script

A start script needs to be added to prepare the application for execution in the Cloud Foundry Environment.

 1. To add a start script, add the following property under the `scripts` section of package.json

   ```JSON
   "start": "node index.js",
   ```

 2. The updated package.json looks as follows:

   ```JSON
   {
    "name": "router",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
    },
    "author": "",
    "license": "ISC",
    "dependencies": {
    "@sap/approuter": "^11.2.1",
    "@sap/asp-middleware": "^1.0.9"
    }
   }
   ```

### Create the start script index.js

 1. Create the file `index.js`. The  `index.js` file must be created in the `router` folder.

    ![New File](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/NewFile.png)

 2. The JavaScript code for the application must be written here. The minimum code required is the following:

   ```JavaScript
   const approuter = require('@sap/approuter');
   const ar = approuter();

   ar.start({
     extensions: [ require('@sap/asp-middleware') ]
   });
   ```

   It will load the approuter and the asp-middleware and ensures that both components are wired. Additionally, the approuter is started.

### Configure the routes

To make sure that the approuter routes all relevant requests to the ABAP Solution, a routing configuration file needs to be created and configured.

 1. Create a file named xs-app.json in the same folder where you created the index.js file. Add ABAP endpoint to both the routes.

    It should have the following content:

   ```JSON
   {
     "authenticationMethod": "route",
     "welcomeFile": "/ui",
     "logout": {
     "logoutEndpoint": "/sap/public/bc/icf/logoff",
     "logoutPage": "/ui"
     },
     "routes": [
     {
     "source": "^/sap/(.*)$",
     "target": "/sap/$1",
     "authenticationType": "xsuaa",
     "service": "com.sap.cloud.abap.solution",
     "csrfProtection": false,
     "endpoint": "abap"
     },
     {
     "source": "^/ui(.*)$",
     "target": "/ui$1",
     "authenticationType": "xsuaa",
     "service": "com.sap.cloud.abap.solution",
     "csrfProtection": false,
     "endpoint": "abap"
     }
     ]
   }
   ```

### Test the router

 1. To test that everything works, execute the below in your command prompt

   ```Shell/Bash
   npm start
   ```

   As a result, you should see the following error message: 'Error: No ABAP Solution credentials found in environment'.

   ![Error as expected](https://raw.githubusercontent.com/sap-tutorials/abap-core-development/main/tutorials/abap-environment-saas-mta-approuter/ErrorAsExpected.png)

   This tells us that the middleware was loaded as a dependency and that the start command is correct.

### Test yourself

---