File upload (and download) support for custom engine agent deployed with bot services in copilot chat

Question

File upload (and download) support for custom engine agent deployed with bot services in copilot chat

Samuel Aguilar-Lussier 0

We have created a custom engine agent with Microsoft agent framework wrapped in M365 agent SDK. The goal was to deploy to copilot chat but the main use case is for document analysis and this is a very recurrent use case so it is very limiting.

The know issues of M365 copilot extensibility states files can't be uploaded or returned by custom engine agents as a shortage of the copilot platform. (https://learn.microsoft.com/en-us/microsoft-365/copilot/extensibility/known-issues)

This is a followup of an issue reported on the agent toolkit github. (https://github.com/OfficeDev/microsoft-365-agents-toolkit/issues/15325)

When can we expect file support in copilot chat.

Thank you

Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-05-25T06:58:54.41+00:00

As of now (May 2026), Microsoft has not announced a specific timeline for enabling file upload or file return support for custom engine agents in Copilot Chat. Below is Microsoft’s official changelog page for new features and updates related to extending Microsoft 365 Copilot with custom agents, plugins, connectors, and APIs: https://learn.microsoft.com/en-us/microsoft-365/copilot/extensibility/whats-new
Samuel Aguilar-Lussier 0 Reputation points

2026-05-25T13:25:53.85+00:00

Thank you for your answer. The documentation is unclear on the side of Teams. Do m365 agent sdk published in teams with Bot services support file exchange in Teams ? Thank you.
Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-05-26T06:57:56.9766667+00:00

In Microsoft Teams, M365 Agents SDK–based custom engine agents do not currently support direct file exchange (uploading files to the agent or returning files as outputs). This limitation is the same as in Copilot Chat and is not Teams-specific.

Agents can work with file content indirectly (for example via SharePoint/OneDrive links or external processing through tools/connectors), but native file transfer between the user and the agent is not supported today.
Samuel Aguilar-Lussier 0 Reputation points

2026-05-26T13:43:39.19+00:00

So is there a way to publish custom engine agents from bot services to users in the Microsoft environment that supports file exchange ?
Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-06-08T09:35:49.13+00:00

Today, there is no supported way to publish a custom engine agent (built with M365 Agents SDK / Bot Service) into Microsoft 365 experiences (Copilot Chat or Teams Copilot) that enables native file upload/download or file exchange with the agent. The current extensibility model intentionally does not expose direct file transfer capabilities for custom engine agents, regardless of whether they are hosted via Bot Service or published to Teams.
Ben Clarke 0 Reputation points

2026-08-16T16:46:01.8+00:00

Please add this to the roadmap Prasad! Sending and receiving files and images is core AI agent functionality

Your answer

Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-05-25T06:58:54.41+00:00

As of now (May 2026), Microsoft has not announced a specific timeline for enabling file upload or file return support for custom engine agents in Copilot Chat. Below is Microsoft’s official changelog page for new features and updates related to extending Microsoft 365 Copilot with custom agents, plugins, connectors, and APIs: https://learn.microsoft.com/en-us/microsoft-365/copilot/extensibility/whats-new
Samuel Aguilar-Lussier 0 Reputation points

2026-05-25T13:25:53.85+00:00

Thank you for your answer. The documentation is unclear on the side of Teams. Do m365 agent sdk published in teams with Bot services support file exchange in Teams ? Thank you.
Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-05-26T06:57:56.9766667+00:00

In Microsoft Teams, M365 Agents SDK–based custom engine agents do not currently support direct file exchange (uploading files to the agent or returning files as outputs). This limitation is the same as in Copilot Chat and is not Teams-specific.

Agents can work with file content indirectly (for example via SharePoint/OneDrive links or external processing through tools/connectors), but native file transfer between the user and the agent is not supported today.
Samuel Aguilar-Lussier 0 Reputation points

2026-05-26T13:43:39.19+00:00

So is there a way to publish custom engine agents from bot services to users in the Microsoft environment that supports file exchange ?
Prasad-MSFT 10,546 Reputation points Microsoft External Staff Moderator

2026-06-08T09:35:49.13+00:00

Today, there is no supported way to publish a custom engine agent (built with M365 Agents SDK / Bot Service) into Microsoft 365 experiences (Copilot Chat or Teams Copilot) that enables native file upload/download or file exchange with the agent. The current extensibility model intentionally does not expose direct file transfer capabilities for custom engine agents, regardless of whether they are hosted via Bot Service or published to Teams.
Ben Clarke 0 Reputation points

2026-08-16T16:46:01.8+00:00

Please add this to the roadmap Prasad! Sending and receiving files and images is core AI agent functionality