SharePoint cleans up its agents: your roadmap until March 2027

Microsoft is cleaning up the agents in SharePoint, and doing it rather quietly. Two Message Center posts cover the same topic: MC1481325 on the SharePoint Page Agent and MC1511052 on agents in the .agent file format. The first one is happening right now, the second one has a hard deadline at the end of March 2027. If you start now, you have plenty of time. If you start in February, you have stress.

Two retirements that are easily mixed up

	Page Agent	.agent files
Message	MC1481325	MC1511052
What is it?	Frontier agent that creates SharePoint pages from Copilot chats	Agents that users created as files in SharePoint or OneDrive
When?	Retired between mid-October and mid-November 2026	Work until the end of March 2027, then stop
Replacement	Copilot directly in SharePoint	Copilot in SharePoint, skills or Copilot Agent Builder
Effort	low	significant, depending on the number

The Page Agent is done quickly. The real work lies in the .agent files.

The Page Agent: leaving now, pages stay

The SharePoint Page Agent was a Frontier feature. Microsoft retires it between mid-October and mid-November and replaces it with Copilot directly in SharePoint. Pages created with the agent remain.

💡 Tip
You do not have to wait for the rollout to finish. AI admins can already disable the Page Agent in Agent 365 and set the pace of the switch themselves. Let authors know beforehand that they will edit pages directly with Copilot in SharePoint from now on.

The .agent files: the bigger topic

Ever since SharePoint agents became available, practically every site member could create an agent. It ended up as an .agent file in the library. Exactly this file format is now being phased out.

Important for the big picture: agents in SharePoint and OneDrive are not being retired, only the .agent file format. From now on, agents are created through Copilot Agent Builder and land in the plugin store of the Copilot app, managed through Agent 365.

From mid-November 2026, three things change:

• Anyone who creates an agent in SharePoint or OneDrive ends up in Copilot Agent Builder. No more .agent files are created.
• The “Upgrade to Microsoft 365 agent” button appears in the SharePoint builder.
• Copilot in SharePoint gets the convert-agent-file-to-skill skill.

After the end of March 2027, .agent files stop responding, neither in Teams chats and channels nor in the Copilot app. In SharePoint, the file only shows an upgrade notice, and the Agent Link web part and the immersive viewer stop working as well.

⚠️ Attention
Microsoft does not upgrade a single agent automatically. Agent owners or site owners have to review every agent themselves and choose an upgrade path.

Four paths, depending on what the agent does today

The agent…	Recommended path
mainly answers questions about the site’s content	Use Copilot in SharePoint directly
performs a recurring task on the site	Convert it to a skill
provides its own Q&A, retrieval or analysis experience	Upgrade with Copilot Agent Builder
is a Copilot Studio agent published to SharePoint	Publish it to the Copilot app, no rebuild needed

And a fifth path that Microsoft recommends itself: simply archive or delete agents without usage or without a clear owner.

The pitfalls when upgrading

Permissions do not carry over. An .agent file inherits the SharePoint permissions of its library. An agent from Agent Builder, on the other hand, is shared with people, groups and email addresses, not with SharePoint groups. If the agent was shared with the whole organization, that stays after the upgrade. Otherwise, the new agent is private at first.

The usage history is lost. Analytics start from zero after the upgrade. If you need old numbers for reports, save them beforehand.

Teams needs manual work. In Teams chats and channels, you have to remove the agent after the upgrade and add it again.

The spot in the chat pane goes away. An upgraded agent can no longer be the main agent in the site’s chat pane. Instead, it goes onto the page via the Agent Chat web part. That web part, however, is still announced as “coming soon”.

Billing changes. The SharePoint agents pay-as-you-go model only applies to .agent files. Upgraded agents follow the licensing model of the Copilot app. If you use pay-as-you-go today, clarify this with whoever owns the budget.

Your roadmap until March 2027

Step 1: Now in October: inventory. Find all .agent files. You can use the agent reports in SharePoint Advanced Management, the agent registry in the admin center filtered on SharePoint agents, search, and for owners the “Owned by you” section under Build in SharePoint. For each agent, note owner, audience, purpose, knowledge sources and where it is used.

Step 2: Until mid-November: prepare. Make sure agent creators are allowed to share agents. Clarify licensing and billing. Update guides, training and support processes before agent creation changes, otherwise the first tickets land on your desk.

Step 3: From mid-November: upgrade. Start with the critical agents: heavily used, broadly shared, embedded on pages, distributed in Teams or using pay-as-you-go. Unused agents without an owner go away.

Step 4: Until February 2027: test. Test sharing, access to the content, placement in Teams and SharePoint, and typical prompts with real users.

Step 5: Until the end of March 2027: clean up. Delete the old .agent files as soon as the replacement works. According to Microsoft, that is also the easiest way to track progress.

What stays

Microsoft is not switching anything off overnight here. Five months of lead time are fair. But with no automatic upgrade, new sharing rules and lost history, this is not a one-click topic. And because site members could create .agent files, in many tenants nobody knows how many there actually are. That is exactly why the roadmap starts with the inventory, and it starts now.

☕ Espresso Moment: If you only put the coffee on when the guests ring the bell, you serve it lukewarm. The inventory is your preheating.

Your takeaways

• Page Agent (MC1481325) and .agent files (MC1511052) are two separate topics with different deadlines.
• You can already disable the Page Agent in Agent 365.
• .agent files work until the end of March 2027, then they stop. There is no automatic upgrade.
• Take inventory now: SAM agent reports, agent registry, search.
• Choose the right path per agent: Copilot in SharePoint, skill, Agent Builder or deletion.
• Plan permissions, Teams placement, usage data and billing consciously.

Message Center posts: MC1481325, MC1511052

How many .agent files did your inventory find? Tell me on LinkedIn, I am curious how big the sprawl really is.