The Case of the Mysterious SharePoint Embedded Containers

Oddly Named SharePoint Embedded Containers Show Up for Copilot Studio

Microsoft 365 tenant administrators can be swamped with message center notifications, reports about service health issues, and automated email generated by Entra ID and other workloads. Other more important things usually get in the way and often no great harm is done. Right now, there are 830 notifications in the message center for my tenant, and probably only 20% of the notifications are what I consider important. For instance, knowing that a new channel update is available for the Office apps isn’t usually a critical event.

In any case, some gems do appear, and it’s important that tenant administrators keep an eye on what’s happening. Let’s discuss an example involving SharePoint Embedded and Copilot Studio to illustrate the point.

The Set of SharePoint Embedded Containers with GUID Names

At first glance, message center notification MC1058260 (last updated 12 May 2025, Microsoft 365 roadmap item 489214), titled “Microsoft 365 Copilot: Admin controls and user file uploads for agent knowledge sources” didn’t seem too worrying. Given Microsoft’s current preoccupation with AI, it’s unsurprising that flood of notifications describing various Copilot enhancements appear weekly. As I don’t use Copilot Studio much, it was easy to assume that a development won’t impact my tenant.

When investigating how Loop workspaces connected to Teams standard channels, I noticed a bunch of strange containers for the Declarative Agent app had appeared in SharePoint Embedded (Figure 1). Some process had created these containers in three batches on April 27 (3:25am), 8 May (1:53am), and 15 May (2:21pm). All the containers appeared to be empty. The only clue was the application name, indicating that the containers are related to some form of agents.

Agents process information from knowledge sources like SharePoint Online sites. MC1058260 explains that users will soon be able to upload up to 20 documents for agents to use as knowledge sources, and when this happens, the uploaded files are stored in “tenant-owned Microsoft SharePoint Embedded (SPE) containers.” MC1058260 goes on to note that “As part of this rollout, we will pre-provision a limited set of SPE containers in your tenant.” The mystery is solved because these containers are the pre-provisioned containers mentioned by MC1058260. I assume that Microsoft creates the containers to make it faster for users to upload documents (because they don’t have to wait for an agent to create a container).

Adding Files as Knowledge Sources for Agents

My tenant ended up with 80 pre-provisioned containers (so far – I have no idea if more provisioning cycles will happen in the future). As far as I can tell, the provisioning operation didn’t generate any audit records. At least, audit log searches for the creation times for the containers turn up nothing of interest.

My tenant doesn’t have 80 agents in use (the number is more like 8), so I assume that the pre-provisioned containers are a pool that agents can use. To test the theory, I edited an agent that I created with Copilot Studio a couple of months ago and added the source Word document for the Automating Microsoft 365 with PowerShell eBook as a knowledge source (Figure 2).

What I expected to happen is an allocation of one of the pre-provisioned containers to the agent and an update to the container name to change it from the GUID used by the pre-provisioning routine to the name of the agent. Updates don’t happen quickly in the SharePoint admin center and site and containers data is usually at least two days behind real time, so I was prepared to wait. However, no change showed up over the next few days.

The Mysterious SharePoint Embedded Containers Disappear

And then, Microsoft hid the pre-provisioned containers. I had chatted to some Microsoft contacts and complained about the mysterious containers, so I guess they acted. In any case, there’s now no trace of the containers and I can’t find out if the updated agent took over a container. And as I don’t know the application identifier for the Declarative Agent app, I can’t use the Get-SPOContainer cmdlet to retrieve any details like the storage consumption (or name) to check if anything had changed in the set of containers.

It’s probably best that Microsoft hides these containers when they are newly created and empty. However, once a container is used by an agent, I think it should show up in the set of active containers displayed in the SharePoint admin center, if only because the storage consumed by the container is charged against the tenant SharePoint Online storage quota. It’s the kind of detail that Microsoft needs to deliver for tenant-wide agent management.

The mystery is solved, and I learned how to add a file as a knowledge source for an agent. Keep an eye on the notifications posted to the message center. You might even learn something too!

---

Insight like this doesn’t come easily. You’ve got to know the technology and understand how to look behind the scenes. Benefit from the knowledge and experience of the Office 365 for IT Pros team by subscribing to the best eBook covering Office 365 and the wider Microsoft 365 ecosystem.