# Handle an incoming message

 Note:
Before you can get started, you need to do the following:

- 
- [Node.js](https://nodejs.org/en/) and a familiarity with how to create a new app.
- [ngrok](https://ngrok.com/). You'll use ngrok to open a tunnel to your local server.


Using the Conversation API, you can receive and respond to messages from any channel you have configured. This tutorial shows you how to set up a Node.js application that receives and responds to messages.

 Note:
This tutorial is easier to accomplish if you have already completed the steps for [sending a message](/docs/conversation/getting-started/node/send-message).

Steps:
1. [Set up](#set-up-your-nodejs-application) your Node.js application
2. [Configure](#configure-your-webhook) your Conversation API webhook
3. [Test](#test-the-application) the application


## 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:

1. Create a folder called `conv-receive`
2. Navigate into the folder you created and run the following command.

```shell
npm init
```
This command adds the node_modules folder and 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.
3. Add the fetch package with npm to generate the necessary dependencies. In this application, we are going to use Express to handle incoming requests.

```shell
npm install cross-fetch
npm install express
```


### Create your file

Note:
This tutorial uses basic authentication for testing purposes. We recommend in a production environment you use OAauth 2.0 authentication. Read more about [authentication methods](/docs/conversation/api-reference/#authentication).

Create a new file named `index.js` in the project and paste the provided "index.js" code found on this page into the file.

index.js
// Get your Access Key and Access Secret at dashboard.sinch.com/settings/access-keys
const fetch = require('cross-fetch');
const express = require('express');
const app = express();
const port = 3000;
app.use(express.json());

const ACCESS_KEY = "";
const ACCESS_SECRET = "";

app.post("/", async (req, res) => {
    var requestBody = req.body;
    console.log(requestBody);
    if (requestBody.message != undefined) {
        const sendMessage = {
            app_id: requestBody.app_id,
            recipient: {
                contact_id: requestBody.message.contact_id
            },
            message: {
                text_message: {
                    text: "You sent: " + requestBody.message.contact_message.text_message.text
                }
            },
            channel_priority_order: [requestBody.message.channel_identity.channel]
        };
        console.log(sendMessage);
    
        let result = await fetch(
            "https://us.conversation.api.sinch.com/v1/projects/" + requestBody.project_id + "/messages:send",
            {
                method: "POST",
                headers: {
                    "Content-Type": "application/json",
                    Authorization: 'Basic ' + Buffer.from(ACCESS_KEY + ":" + ACCESS_SECRET).toString('base64')
                },
                body: JSON.stringify(sendMessage)
            }
        );
        console.log(await result.json());
        res.send("Ok");
    }
    else {
        res.send("Ok");
    }
});

app.listen(port, () => {
    console.log("Listening at http://localhost:" + port);
});
Note:
This sample code is configured for the US region. If your Conversation API app wasn't created in the US region, replace all instances of `https://us.conversation.api.sinch.com` with `https://eu.conversation.api.sinch.com` in the sample code.

This code starts a server that listens for incoming messages. It then sends a [text message](/docs/conversation/message-types/text-message/) in response.

### Fill in your parameters

1. Assign your values to the following parameters:
ParameterYour valueACCESS_KEYFind your access key on your Sinch [dashboard](https://dashboard.sinch.com/settings/access-keys).ACCESS_SECRET
     Find your access secret on your Sinch [dashboard](https://dashboard.sinch.com/settings/access-keys).Note:Access secrets are only available during initial key creation.
2. Save the file.


### Start your web server and set up a tunnel

1. Start the server by executing the following command in your terminal or command prompt:

```shell
node index.js
```
2. Now you need to open a tunnel to the server you just set up. We are using [ngrok](https://ngrok.com/) for this.
If you don't have ngrok installed already you can install it with the following command:

```shell
npm install ngrok -g
```
3. Open a new terminal or command prompt and enter:

```shell
ngrok http 3000
```
4. Copy the HTTP address that ends with .ngrok.io.


## Configure your webhook

For your application to receive messages from Conversation API, you must configure a webhook in your Conversation API app. For detailed instructions on configuring a webhook, click [here](https://community.sinch.com/t5/Conversation-API/How-to-add-a-webhook-to-a-Conversation-API-app/ta-p/8100).

Set your webhook URL to the HTTP address you copied in the previous step. Additionally, assign the following triggers:

- `CONVERSATION_START`
- `CONVERSATION_STOP`
- `EVENT_DELIVERY`
- `EVENT_INBOUND`
- `MESSAGE_DELIVERY`
- `MESSAGE_INBOUND`
- `UNSUPPORTED`


## Test the application

Now that your server is running and your webhook is configured, you can test the application.

From your messaging platform, send your Conversation API app a message. You will receive a message back in response on the messaging platform.

## Additional resources

Read the links below to learn more:

- [Learn more about the `/messages` endpoint](/docs/conversation/api-reference/conversation/messages/)
- [Learn more about different message types](/docs/conversation/message-types)
- [Learn more about channels](/docs/conversation/channel-support)
- [API specification](/docs/conversation/api-reference/)