Receive an incoming SMS Message

Note:

Before you can get started, you need the following already set up:

Set all SMS API configuration settings.
Node.js and a familiarity with how to create a new app.
ngrok. You'll use ngrok to open a tunnel to your local server.

Learn how to handle incoming SMS messages in a Node.js application with the Sinch Node.js SDK.

Steps:

Set up your Node.js application
Start your web server and set up a tunnel
Send your SMS message

Set up your Node.js application

First we'll create a Node project using npm. This creates a package.json and the core dependencies necessary to start coding.

To create the project, do the following steps:

Create a folder called receive-sms-app
Navigate into the folder you created and run the following command.
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```
npm init
```
This command adds the package.json file. You will be prompted to provide values for the fields. For this tutorial, you can simply accept the default values and press enter at each stage.
You can install the Sinch Node.js SDK using either NPM or Yarn:
NPMYarn
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npm install @sinch/sdk-core
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yarn add @sinch/sdk-core
Next, install the Fastify package. Fastify is a lightweight webserver that we will use to respond to webhooks.
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```
npm install fastify
```

Note:

If your using React or Angular, the @sinch/sdk-core and fastify packages can be imported using import statements.

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import { SinchClient } from '@sinch/sdk-core';
import Fastify from 'fastify';

Create your file

Create a new file named index.js in the project and paste the provided "Receive an SMS message" code into the file.

Modify your application

The code provided includes placeholder parameters. You'll need to update the parameters detailed in the following subsections with your values.

Initialize the client

Before initializing a client using this SDK, you'll need three pieces of information:

Your Project ID
An access key ID
An access key Secret

These values can be found on the Access Keys page of the Customer Dashboard. You can also create new access key IDs and Secrets, if required.

Note:

If you have trouble accessing the above link, ensure that you have gained access to the Conversation API by accepting the corresponding terms and conditions.

To start using the SDK, you need to initialize the main client class with your credentials from your Sinch dashboard.

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const {SinchClient} = require('@sinch/sdk-core');

const sinchClient = new SinchClient({
    projectId: "YOUR_project_id",
    keyId: "YOUR_access_key",
    keySecret: "YOUR_access_secret"
});

Note:

For testing purposes on your local environment it's fine to use hardcoded values, but before deploying to production we strongly recommend using environment variables to store the credentials, as in the following example:

.env File

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PROJECTID="YOUR_project_id"
ACCESSKEY="YOUR_access_key"
ACCESSSECRET="YOUR_access_secret"

app.js File

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const {SinchClient} = require('@sinch/sdk-core');

const sinchClient = new SinchClient({
    projectId: process.env.PROJECTID,
    keyId: process.env.ACCESSKEY,
    keySecret: process.env.ACCESSSECRET
});

Note:

If you are using the Node.js SDK for multiple products that use different sets of authentication credentials, you can include all of the relevant credentials in the same configuration object, as in the following example:

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const {SinchClient} = require('@sinch/sdk-core');

const sinchClient = new SinchClient({
    projectId: "YOUR_project_id",
    keyId: "YOUR_access_key",
    keySecret: "YOUR_access_secret",
    applicationKey: "YOUR_application_key",
    applicationSecret: "YOUR_application_secret"
});

Start your web server and set up a tunnel

Start the server by executing the following command:
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```
node index.js
```
Open a tunnel to the server you just set up. We are using ngrok for this. If you don't have ngrok installed already, install it with the following command:
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```
npm install ngrok -g
```
Open a terminal or command prompt and enter:
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```
ngrok http 3000
```

You will see a screen like the following. ngrok screenshot

On the highlighed "Forwarding" line, copy the address ending in .ngrok.io.

Configure your Callback URL

To configure a callback URL for your Sinch account, login to your dashboard.
Click on the service plan ID link and edit the Callback URL field with the ngrok.io domain URL from the previous step.

Send your SMS message

Now send an SMS message to your Sinch number from your mobile phone and you will get an automatic reply.

Next steps

The code you used in the index.js file listens for a webhook sent from the Sinch servers and then sends a POST request to the Sinch API /batches endpoint to send the SMS message.

Explore the API specification to test more endpoints.

Additional resources

Click here to read more about the batches endpoint.