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pythongmailgmail-apigoogle-api-js-client

Gmail API retrieving Message ID after sending/insert call

Is there a way to get the Message ID after inserting a message via the API's response?

For example, I use the below code to insert the initial message:

try:
    message1 = service.users().messages().insert(userId='me', body=temp).execute()
    print(f"{message1['id']} / {message1['threadId']}")

In this API call, id and threadId are the same, a 16 character string.

Next, I insert a reply. I go into Gmail to get the Message ID (<...@mail.gmail.com>) and set this up in the next API call as follows:

message['subject'] = 'Re: test subject'
message['In-Reply-To'] = '<...@mail.gmail.com>'
message['References'] = '<...@mail.gmail.com>'
encoded_message = urlsafe_b64encode(message.as_bytes())
temp = {'raw': encoded_message.decode(), 'labelIds': ['UNREAD'], 'threadId': 'THREAD_ID_FROM_FIRST_CALL'}
try:
    message1 = service.users().messages().insert(userId='me', body=temp).execute()
    print(f"{message1['id']} / {message1['threadId']}")

The response here is a different message1['id'] but the same message1['threadId'] as above, so it shows up properly threaded in Gmail. But, is there a way to easily get Message ID from the response body? Can I generate it from message1['id']? The alternative is to make a second API to find a message by message1['id'] but I'm trying to avoid that. Thanks.

Solution

  • Unfortunately, there's no direct way to retrieve the new messageId apart from making a new API call.

    This is due to the fact that messageId and threadId are two different parameters:

    • messageId corresponding to the message in the thread

    • threadId corresponding to the thread

    So if you insert a new reply into a thread, the threadId will obviously be the same as the one associated to the original message, but the new reply will receive a new id - a messageId which is unique and has nothing to do with the threadId associated with it.

    What you can do instead is to group all the threads by their threadIds and based on that, insert a new reply. In this way, you can also easily gather the messageIds from that specific thread.

    Reference