Attach File to Row

The Attach File to Row action uploads a file to a specific row. There is no native Power Automate action for this, so it’s another gap this connector fills directly.

Parameters

Parameter	Required	Description
sheetId	Required	The ID of the sheet containing the row.
rowId	Required	The ID of the row to attach the file to.
File	Required	The file content to upload.
filename	Required	The name to give the uploaded file, including its extension. See below.
Content-Type	Optional	MIME type of the file being uploaded. See below.

Using sheetId

This can be a fixed, hardcoded value taken from the properties of a sheet in Smartsheet, but it is very common to get the sheetId dynamically from a trigger or another action.

Using rowId

Almost always comes from somewhere dynamic such as a trigger that fires on a specific row, or a previous step in the flow (like looping over rows from Get Sheet). Hardcoding this value is usually only done when learning the action or troubleshooting.

Using file

This action accepts the file content directly, which is the same file content output you’d get from a “Get file content” action (like from OneDrive or SharePoint), a PDF generation step, or an HTTP action that returns a file.

Using filename

Always include the file extension (e.g. report.pdf, not report). Smartsheet uses the extension in this name to decide which file-type icon to display. The connector automatically encodes for spaces and special characters, so no manual formatting is needed.

Using Content-Type

This field is optional, but accepts MIME types for the file type, as shown in the Content-Type column in the table below. This is not an exhaustive list, but covers common documents. If it is left blank, Smartsheet makes its best guess based on the extension of the file.

File type	Content-Type
PDF	application/pdf
PNG image	image/png
JPEG image	image/jpeg
Word document	application/vnd.openxmlformats-officedocument.wordprocessingml.document
Excel spreadsheet	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Plain text	text/plain
Generic/unknown	application/octet-stream

Example

A permit document is uploaded to SharePoint for a specific project, and the permit document is attached to the associated project row in Smartsheet.

A filled-out example: SheetId and RowId come from earlier steps in the flow, Filename is typed in directly, File is a Get file content output from a previous action, and the optional Content-Type is set explicitly under Advanced parameters.

What you get back

The newly created attachment object, including its id, filename, and attachmentType (this will be FILE, since that’s the only type this action creates).

Gotchas