Dialogflow easy way for authorization - node.js

Question

Does exist an easy way to connect Dialogflow agent to node.js code? When I use this code with the correct projectID taken from the Dialogflow agent's settings page, I have the following error:
Error: Unexpected error while acquiring application default credentials: Could not load the default credentials. Browse to https://developers.google.com/accounts/docs/application-default-credentials for more information.
const sessionClient = new dialogflow.SessionsClient();
const sessionPath = sessionClient.sessionPath(projectId, sessionId);
I visited the page, but for what I want I think is quite confused (they quotes other API and a lot of setting), how can I solve this?
I want to take informations from a file and loading all without installing third party APIs.

Answer 1

It is not very well documented, but the easiest way to authenticate is using the JSON file provided on your google cloud platform console.
const sessionClient = new dialogflow.SessionsClient({
keyFilename: '/path/to/google.json'
});
const sessionPath = sessionClient.sessionPath(projectId, sessionId);
This also works for all the other clients. ContextsClients, EntityTypesClient and so on.

Answer 2

I am writing the code, which worked for me. Please follow all the steps provided in Reference link 2 and for coding purpose you can use the snippet provided.
I have also added the sample JSON of Google Cloud Oauth
References:
https://www.npmjs.com/package/dialogflow#samples
https://medium.com/#tzahi/how-to-setup-dialogflow-v2-authentication-programmatically-with-node-js-b37fa4815d89
//Downloaded JSON format
{
"type": "service_account",
"project_id": "mybot",
"private_key_id": "123456asd",
"private_key": "YOURKEY",
"client_email": "yourID#mybot.iam.gserviceaccount.com",
"client_id": "098091234",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://oauth2.googleapis.com/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/yourID%40mybot.iam.gserviceaccount.com"
}
//------*********************---------------------------
//
const projectId = 'mybot';
//https://dialogflow.com/docs/agents#settings
// generate session id (currently hard coded)
const sessionId = '981dbc33-7c54-5419-2cce-edf90efd2170';
const query = 'hello';
const languageCode = 'en-US';
// Instantiate a DialogFlow client.
const dialogflow = require('dialogflow');
let privateKey = 'YourKey';
// as per goolgle json
let clientEmail = "yourID#mybot.iam.gserviceaccount.com";
let config = {
credentials: {
private_key: privateKey,
client_email: clientEmail
}
}
const sessionClient = new dialogflow.SessionsClient(config);
// Define session path
const sessionPath = sessionClient.sessionPath(projectId, sessionId);
// The text query request.
const request = {
session: sessionPath,
queryInput: {
text: {
text: query,
languageCode: languageCode,
},
},
};
// Send request and log result
sessionClient
.detectIntent(request)
.then(responses => {
console.log('Detected intent');
const result = responses[0].queryResult;
console.log(` Query: ${result.queryText}`);
console.log(` Response: ${result.fulfillmentText}`);
if (result.intent) {
console.log(` Intent: ${result.intent.displayName}`);
} else {
console.log(` No intent matched.`);
}
})
.catch(err => {
console.error('ERROR:', err);
});

Answer 3

I have the same issue few months ago, check this, this is how i solve it.
From your JSON that Google Cloud extract this lines.
const dialogflow = require('dialogflow');
const LANGUAGE_CODE = 'en-US'
const projectId = 'projectid';
const sessionId = 'sessionId';
const query = 'text to check';
let privateKey = "private key JSON";
let clientEmail = "email acount from JSON";
let config = {
credentials: {
private_key: privateKey,
client_email: clientEmail
}
};
sessionClient = new dialogflow.SessionsClient(config);
async function sendTextMessageToDialogFlow(textMessage, sessionId) {
// Define session path
const sessionPath = this.sessionClient.sessionPath(projectId, sessionId);
// The text query request.
const request = {
session: sessionPath,
queryInput: {
text: {
text: textMessage,
languageCode: LANGUAGE_CODE
}
}
}
try {
let responses = await this.sessionClient.detectIntent(request)
console.log('DialogFlow.sendTextMessageToDialogFlow: Detected intent', responses);
return responses
} catch (err) {
console.error('DialogFlow.sendTextMessageToDialogFlow ERROR:', err);
throw err
}
};
sendTextMessageToDialogFlow(query, sessionId)

Answer 4

Since the original question, the documentation for Dialogflow authentication has been improved. You should find all your answers here:
Authentication and access contro

Answer 5

I follow the above solutions with little changes :
// A unique identifier for the given session
const sessionId = uuid.v4();
// Create a new session
const sessionClient = new dialogflow.SessionsClient({
keyFilename: require("path").join('config/google-credential.json')
});
const sessionPath = sessionClient.sessionPath(process.env.DIALOGFLOW_PROJECTID, sessionId);