Trying to write a calendar event using Microsoft Graph API issue - node.js

Question

I'm trying to use the Microsoft Graph API to write calendar events within my company.
First of all let me give you a little bit of context.
I'm building a node API that uses Microsoft Graph to write calendar events, so I configured my application inside the Azure Active Directory with the following application permission
I granted administrator consent as you can see from the picture.
I was also able to get the access token using msal-node
const graphToken = async () => {
const azureConfig = {
auth: {
clientId: process.env.CLIENT_ID,
authority: `https://login.microsoftonline.com/${process.env.TENANT_ID}`,
clientSecret: process.env.CLIENT_SECRET,
},
}
const tokenRequest = {
scopes: [process.env.GRAPH_ENDPOINT + '/.default'],
}
const cca = new msal.ConfidentialClientApplication(azureConfig)
const authRespose = await cca.acquireTokenByClientCredential(tokenRequest)
if (authRespose) {
return authRespose.accessToken
}
return null
}
The only thing that sounds me a little odd, is the scope set to [process.env.GRAPH_ENDPOINT + '/.default'] I tried to change it ex. [process.env.GRAPH_ENDPOINT + '/Calendar.ReadWrite'] but it fires an excepion.
The next thing I'm able to do is retrive all calendars a user have right to write to, using the following Graph endpoint:
https://graph.microsoft.com/v1.0/users/user#example.com/calendars
Now the issue, when I try to do a POST request to write a calendar event for example
POST https://graph.microsoft.com/v1.0/users/{userId}/calendars/{calendarId}/events
{
"subject": "Test",
"body": {
"contentType": "HTML",
"content": "Test"
},
"start": {
"dateTime": "2022-11-09T16:00:00",
"timeZone": "Europe/Rome"
},
"end": {
"dateTime": "2022-11-09T17:00:00",
"timeZone": "Europe/Rome"
}
}
Note that calendarId is one of the id's from the previous call
(Not the default calendar of userId)
I got a 403 Forbidden with the following response
{
"error": {
"code": "ErrorAccessDenied",
"message": "Access is denied. Check credentials and try again."
}
}
I also decoded my token to see if I get some info on the root cause of the 403 error, I found this:
...
"roles": [
"Calendars.Read",
"User.Read.All",
"Calendars.ReadWrite"
],
...
It seems correct to me.
I don't get if it is a scope issue, an authentication issue or something I'm missing, can someone pinpoint me in the right direction?
Thanks in advance

Answer 1

Basically it was my fault.
I messed up with calendar permissions and my test user had a reviewer permission instead of an author one on the calendar I had to write to
once I was able to identify this issue and change the permission the call response was what expected.
I leave this answer as a reference for anyone that encounter this issue
Thanks anyway