Example - Send a message with an attachment

As described above, in Teams an attachment is a reference to a document, not the document content itself. To send a Teams message with an attachment, the document must already exist in OneDrive or SharePoint. This example shows the required steps to send a Teams message with an attachment, as illustrated in the image below.

What we want to do is generate an Excel file with a list of TODOs and post it to a channel together with a message. Before we can do that, the file must exist in OneDrive or SharePoint. After generating the file, we use the Upload file to OneDrive action to upload it. This action returns information about the OneDrive item, which we then use to create an attachment for the Teams message.

The Generate attachment ID is a Function that simply returns a GUID as a string. We'll use the attachment ID in both the message body and the list of attachments.

To define the attachment, open the Attachments property of the action and apply the following mappings:

Attachment property	Map from
Id	The GUID generated by the Function action.
Name	The OneDrive item Name property.
Content type	The string "reference" (without quotes).
Content URL	The OneDrive item WebDavUrl (Or WebUrl) property.

Then, in the Message, reference the attachment using the <attachment> tag.

Your message...
<attachment id="the-guid"></attachment>