Read/Unread status of Twilio SMS

I created a simple Twilio app using TwiMl Bin to store the incoming messages and using REST APIs (https://www.twilio.com/docs/sms/tutorials/how-to-retrieve-and-modify-message-history-node-js) to read messages. There is no read status in messages, is there a way to implement unread messages and mark as unread functionality using Twilio APIs?

This is message JSON received from Twilio API:

{
    "body": "SMS Text",
    "num_segments": "1",
    "direction": "outbound-api",
    "from": "+xxx",
    "date_updated": "Wed, 05 Jan 2022 17:43:48 +0000",
    "price": "-0.00750",
    "error_message": null,
    "uri": "/2010-04-01/Accounts/xxx/Messages/xxx.json",
    "account_sid": "xxx",
    "num_media": "0",
    "to": "+xxx",
    "date_created": "Wed, 05 Jan 2022 17:43:47 +0000",
    "status": "delivered",
    "sid": "xxx",
    "date_sent": "Wed, 05 Jan 2022 17:43:47 +0000",
    "messaging_service_sid": null,
    "error_code": null,
    "price_unit": "USD",
    "api_version": "2010-04-01",
    "subresource_uris": {
        "media": "/2010-04-01/Accounts/xxx/Messages/xxx/Media.json",
        "feedback": "/2010-04-01/Accounts/xxx/Messages/xxx/Feedback.json"
    }
}

There is no field for read/unread status here.

If not using APIs, is it possible to implement this feature using Twilio features like Functions? Trying to avoid implementing web hook and the rest in cloud.

Appreciate your help.

Twilio developer evangelist here.

The SMS protocol has no concept of whether a message has been read or not and Twilio does not try to add that in. That is something your own application will have to implement and store within the context of your app.