Google Calendar API Node JS, can't add attendees with service account - node.js

Question

I'm currently trying to develop a simple Node JS program deployed on a GCP Cloud Function, to use Google Calendar API with a Service Account.
The program is simple, i just want to create an event and add attendees.
My code works well, however i can't add attendees with the service account i have this error :
There was an error contacting the Calendar service: Error: Service accounts cannot invite attendees without Domain-Wide Delegation of Authority.
The API are activated and i allowed the calendar scope on the GSuite Admin Security, my service account have the delegation authority checked on GCP.
I search a lot a solution but nothing solve my problem..
This is the code of my module :
const { google } = require('googleapis');
const sheets = google.sheets('v4');
const SCOPES = ['https://www.googleapis.com/auth/spreadsheets','https://www.googleapis.com/auth/calendar'];
let privatekey = require("../creds.json");
async function getAuthToken() {
let jwtClient = new google.auth.JWT(
privatekey.client_email,
null,
privatekey.private_key,
SCOPES);
//authenticate request
jwtClient.authorize(function (err, tokens) {
if (err) {
console.log(err);
return;
} else {
console.log("Successfully connected!");
}
});
return jwtClient;
}
async function insertEvents(auth,items) {
const calendar = google.calendar({ version: 'v3', auth });
var startDate = new Date();
var endDate = new Date();
startDate.setHours(14, 0, 0, 0);
endDate.setHours(15, 0, 0, 0);
var attendees = [];
items.forEach(function(item){
attendees.push({email: item[2]});
});
var event = {
summary: 'Stack Roulette : It\'s Coffee Time =)',
location: 'Partout, mais avec un café',
description: "",
start: {
dateTime: startDate.toISOString(),
timeZone: 'Europe/London'
},
end: {
dateTime: endDate.toISOString(),
timeZone: 'Europe/London'
},
attendees: attendees,
reminders: {
useDefault: false,
overrides: [
{ method: 'email', minutes: 24 * 60 },
{ method: 'popup', minutes: 10 }
]
},
conferenceData: {
createRequest: {requestId: Math.random().toString(36).substring(2, 10),
conferenceSolution: {
key: {
type: "hangoutsMeet"
}
},}
}
};
calendar.events.insert(
{
auth: auth,
calendarId: 'primary',
resource: event,
conferenceDataVersion: 1
},
function(err, event) {
if (err) {
console.log(
'There was an error contacting the Calendar service: ' + err
);
return;
}
console.log('Event created: %s', event.data.htmlLink);
}
);
}
module.exports = {
getAuthToken,
getSpreadSheetValues,
insertEvents
}
I precise, there is no Frontend for my application, the code run with a cloud Function like an API Endpoint.
PS : it's not a Firebase Cloud Function, but GCP Cloud Function
If i remove attendees from event creation, it's work well but can't see the event.
Thx for your help

Answer 1

To set up Domain-Wide Delegation of Authority
Visit your cloud console
Go to IAM & Admin -> Service Accounts
Chose the service account you using in your script
Check Enable G Suite Domain-wide Delegation
If you are sure that you already enabled the domain-wide delegation for the correct service account and you encounter issues only when creating events with attendees:
Your issue is likely related to this issue reported on Google's Issue Tracker:
Currently there are restrictions for creation of events with attendees with a service account, especially when the attendees are outside of your domain.

Answer 2

When you create jwtClient, I think you have to put user primary email to JWT method.
Like:
let jwtClient = new google.auth.JWT(
privatekey.client_email,
null,
privatekey.private_key,
SCOPES,
"yourUserPrimaryEmail"); // here