Issue with AppSheet API + Partitions (User Settings) when uploading files via API

[sricse]

Hello community,

I’d like to explain a process we have been using successfully for months and a limitation we are now facing when working with Partitions (User Settings) and the AppSheet API, specifically when uploading files.

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Current Process (Working Correctly)

We work with AppSheet + Google Apps Script and implemented a webhook-like flow to automatically store final reports (PDFs) in the client’s data source, not in the app owner’s Drive.

The process is the following:

1. Generate PDF using AppSheet Bot

   • We use “Create a file” in a Bot.

   • The PDF is temporarily created in the app owner’s Google Drive, in a specific folder we define.

2. Call a Webhook (Google Apps Script)

   • AppSheet sends the file name, row ID, table name, and other metadata.

   • The Apps Script has access only to the specific folder where the PDF was generated.

3. Apps Script Processing

   • Receives the POST request.

   • Locates the generated PDF in the app owner’s Drive.

   • Converts the PDF to Base64.

   • Uses the AppSheet API to upload the file to the correct row and column, simulating a manual file upload.

4. Result

   • AppSheet stores the file in the client’s Drive/data source, not the app owner’s.

   • The file appears correctly in the app.

   • The temporary PDF in the app owner’s Drive is deleted.

This flow has been working perfectly throughout 2025.

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The Problem (With Partitions)

Some of our apps have large datasets, so we use Partitions based on User Settings, for example:

• Year

• Period

Normally, the app is working on the current partition (e.g. Year 2026 – Period 1).

The issue appears when:

• The record we want to update belongs to a previous partition (e.g. Year 2024 – Period 3).

• When the Apps Script uses the AppSheet API to upload the file:

  • AppSheet only searches for the row in the currently active partition

  • The row exists, but in a different sheet/partition

  • Therefore, the API cannot correctly locate or update the record

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What We Are Trying to Achieve

Ideally, we would like one of the following:

• Tell the AppSheet API which partition (year/period) it should use

• Or dynamically set User Settings values (Year / Period) via the API before performing the update

• Or have the API search across partitions, not only the active one

However, from what we have researched:

• User Settings cannot be manipulated via the AppSheet API

• The API always operates under the current app context, including active partitions

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Questions to the Community

1. Has anyone worked with AppSheet API + Partitions + Google Apps Script in a similar scenario?

2. Is there any way to:

   • Control or override User Settings via API?

   • Indicate the target partition when updating a row?

   • Or design partitions in a way that still allows API updates to historical data?

3. Is this a known limitation of the AppSheet API?

Any guidance, workaround, or recommended architecture change would be greatly appreciated.

Thanks in advance!

[Steve]

@sricse

• Control or override User Settings via API?

Not possible.

@sricse

• Indicate the target partition when updating a row?

Nope.

@AleksiAlkio, you have experience with partitions?

[AleksiAlkio]

Yes you can select the partition with the API call inside of json and its parameters. Invoke the API - AppSheet Help

EDIT: Check the sample in “HTTP request body” section. It shows how you can select the values for the Usersettings.