How do I select an AI agent in Copilot within Excel?

Question

I would like to switch the Copilot pane in Excel for Windows to the agent provided by my add-in, but there doesn't seem to be an option to switch agents at all.

The tutorial I'm following, in the "Run the agent" section, clearly gives instructions for opening the Copilot pane (not the standalone Copilot Chat) from within the Excel UI, mentioning Excel by name and telling me to click the Copilot ribbon button. However, it then says "In the Copilot pane, select the hamburger control." There is no hamburger control in the Copilot pane within Excel, or any other input that lets the user switch agents; I can only access my add-in's agent through the standalone Copilot Chat, where it doesn't have access to my Excel workbook's contents. This must be unintentional, since the tutorial's example agent command is meant to modify the color of an Excel workbook cell.

Is this a mistake in the documentation for this (admittedly very new) feature, or is there some way of changing the agent within the Copilot Excel pane that I'm not seeing? A related doc page is marked "preview", but I thought that meant the functionality described would be accessible.

My Excel Copilot task pane:

Answer 1

Dear @Alek Storm,

Thank you for posting your question in the Microsoft Q&A forum.

I understand that technical issues can be frustrating, and I’d love to help you resolve this. Before giving you the best solution, could you please confirm these questions below to help me diagnose the issue more effectively: 

• Excel Version: Are you using Excel from Microsoft 365 (subscription) or a standalone version? And is it updated to the latest build? You can see it via File > Account > About Excel
• Copilot Add-in Type: Is your agent part of a custom Copilot extension or a Microsoft Graph connector? Was it deployed via admin center or sideloaded?
• Agent Registration: Has your agent been registered with the Copilot extensibility framework for Excel specifically, or only for Copilot Chat?
• Environment: Are you testing this in a production tenant or a developer sandbox with preview features enabled?

Based on your description, the Copilot pane in your Excel build does not include the hamburger menu or agent selector that the tutorial describes. That’s expected because:

• The agent picker (the “hamburger” menu / App skills list) inside the Copilot pane in Excel is a preview-only UI and only available in certain Insider builds and flighted tenants.
• On standard or current channels, the Copilot pane only shows the default experience (like in your screenshot), so there’s no way to pick your add-in’s agent there yet.
• The Microsoft Learn pages updated July 30, 2025 describe the preview experience for “Combine Copilot Agents with Office Add-ins". That UI isn’t generally available yet; the docs are written for preview builds where it is enabled. For reference: Combine Copilot Agents with Office Add-ins (preview)

What you can do now:

• Standalone Copilot Chat: You can still access your agent there, but it won’t have workbook context until the in-app UI is available.
• Preview access: If you need the full experience, you’ll need an Insider or developer tenant where the feature is flighted.
• Manifest readiness: Make sure your add-in uses the unified manifest with copilotAgents.declarativeAgents so it’s ready when the pane UI lights up.

I hope this information is helpful. If you have any further questions or need clarification, please feel free to reach out.

Thank you for your patience and understanding.

I'm looking forward for your reply.

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