Creating a PHP webhook for DialogFlow (API.AI)

If you have the choice to go for Python or NodeJS instead of PHP, I recommend using the other two options (between the two, I prefer Python). You will probably find it quite hard to find a lot of discussion online about using PHP with Dialogflow. 

This is intended to be a very basic, beginner’s article for getting started with API.AI webhooksYou can use webhooks to add custom business logic in both Di... using PHP. I am making the following assumptions:

a. You have a website where you can run PHP scripts

b. You have sufficient permissions to be able to create new folders etc on the host without too much difficulty

Code sample

This tutorial is primarily based on the following code sample provided on the API.AI forum:

function processMessage($update) {
    if($update["result"]["action"] == "sayHello"){
        sendMessage(array(
            "source" => $update["result"]["source"],
            "speech" => "Hello from webhook",
            "displayText" => "Hello from webhook",
            "contextOut" => array()
        ));
    }
}

function sendMessage($parameters) {
    echo json_encode($parameters);
}

$update_response = file_get_contents("php://input");
$update = json_decode($update_response, true);
if (isset($update["result"]["action"])) {
    processMessage($update);
}

Note that I made the following changes to the code sample:

a. Stripped out the comments

b. Changed the actionYou define an action in Dialogflow ES intents to tell your w... value from “buscar.nfe” to “sayHello”

c. Changed the speech and displayText values to “Hello from webhook”

Create test.php

To use the above code, start with a file called test.php. Paste the entirety of the code into test.php and save it. Place the file inside a folder called webhook (for example).

Now upload the webhook folder to your website. I will assume, for this example, that you are uploading the folder to the root of your website. If your website is called example.com, then the php file will be located at example.com/webhook/test.php

Add the webhook URL

Under the Fulfillment tab in your API.AI console, add the following URL:

http://www.example.com/webhook/test.php

Make sure you use https instead of http if your site already is https.

Add an action to your intent

Choose an intentBoth Dialogflow ES and Dialogflow CX have the concept of int... that you wish to trigger (let us use the Default Welcome for now). Under the action, you should add the following: sayHello. It should match whatever you are handling in the PHP code.

Trigger the intent

In the API.AI console, type “Hi”. It should trigger the Default Welcome IntentThis is the intent which is automatically added into the Sta... and you should see “Hello from webhook” appearing on your console.