What is `file_annotation` parameter of `chat_postMessage` method?

[0417taehyun]

I want to know how file_annotation parameter works with chat_postMessage method. I already search it on issue and the document of the chat_postMessage method, but there was no appropriate information about it.

    def chat_postMessage(
        self,
        *,
        channel: str,
        text: Optional[str] = None,
        ...
        file_annotation: Optional[str] = None, # > How can I use this? 
        ...
        **kwargs,
    ) -> SlackResponse:

In my case, I use bolt SDK to handle the message events on socket mode, and want to send message to another channels if the message was sent by a user. However, if the file is attached to the origin message, there was no ways to send the same file to the bot message, which was sent by bot with bolt SDK.

I assume to use the file_annotation parameter in the chat_postMessage method, but there was no information to teach how it works. Isn't is supported yet?

[mwbrooks]

Hi @0417taehyun 👋🏻 Thanks for the question!

I'm done some research and learned that the file_annotation parameter was once part of the chat.PostMessage API. However, it's now been deprecated and removed. So it's no longer available in the public Slack API.

We didn't notice that the parameter was removed, which is why it's still part of the Bolt for Python framework. I'll create an issue for us to remove it in an upcoming release!

Thanks for catching this! 🙇🏻

[0417taehyun]

@mwbrooks

Then how can I connect files with messages with message by using chat_postMessage method?
I want to send message by bot with files. Isn't it possible?

[seratch]

@0417taehyun As long as your bot user has access to a file (e.g., the file is shared in a public channel where your app's bot user is a member), your app can share the file by posting a message with a permalink of the file. More specifically, you can have a file's permalink in a message's top-level text property.