Issue with Invalid Label/ID Error When Fetching Email Inbox Using Nylas v3

Hi Nylas Support Team,

I am encountering an issue while retrieving the email inbox using Nylas API v3. I have the ‘Inbox’ folder set as the default. However, when I refresh the inbox or access it for the first time, I receive an error stating: “Invalid label/id.” I have verified multiple times that the folder ID is being passed correctly.

In the case of Gmail, the API request URL becomes:
threads?limit=20&in=INBOX

However, I receive the following error:
{
“request_id”: “7160912290-12bd1c13-0b81-4220-9db8-b2d2effa6062”,
“error”: {
“type”: “provider_error”,
“message”: “Bad Request”,
“provider_error”: {
“error”: {
“code”: 400,
“message”: “Invalid label: AQMkADAwATY0MDABLTQ1YzAtZTNiMy0wMAItMDAKAC4AAAPxxufuAEQOQqXEmH6_yhvrAQA72M2hjLZKTpt2YD42X5QQAAACAQwAAAA=”
}
}
}
}

I logged the URL on the server side, and it shows the following request just before the error:

threads?limit=20&in=AQMkADAwATY0MDABLTQ1YzAtZTNiMy0wMAItMDAKAC4AAAPxxufuAEQOQqXEmH6_yhvrAQA72M2hjLZKTpt2YD42X5QQAAACAQwAAAA=

For Gmail, the expected URL is:
** **threads?limit=20&in=INBOX** **

Initially, the correct URL was logged, but immediately after, the incorrect URL was logged, which caused the error. I believe this may be an issue with the Nylas API. The error does not occur consistently—it happens occasionally during refreshes or when landing on the inbox for the first time.

When using a Hotmail account, the following URL is logged:

threads?limit=20&in=AQMkADAwATY0MDABLTQ1YzAtZTNiMy0wMAItMDAKAC4AAAPxxufuAEQOQqXEmH6_yhvrAQA72M2hjLZKTpt2YD42X5QQAAACAQwAAAA=

This results in the following error:
{
“request_id”: “9249869822-836c05d4-c976-49e7-922c-8582f6d0eca8”,
“error”: {
“type”: “partial_success_error”,
“message”: “One message in thread could not be retrieved. Some messages may have been retrieved”,
“provider_error”: {
“error”: {
“code”: “ApplicationThrottled”,
“message”: “Application is over its MailboxConcurrency limit.”
}
}
}
}

Even though I have set the page size to 20 by default in the request, the issue persists. The error does not occur when navigating between folders. For example, if I click on the ‘Inbox’ folder, the emails load correctly, and no error is displayed. These errors only occur during refreshes or upon the initial load of the inbox screen.

I have followed the Nylas documentation here:

Could you please investigate this issue with your development team? I believe this might be a problem with the Nylas API. Kindly assist in resolving this issue as soon as possible.

Thank you for your help!

Best regards,

Emmad Altaf

Contact me:
Nylasv3@gmail.com

@Blag @ram please look