check before: 2025-12-01
Product:
Copilot, Microsoft 365 Copilot, OneDrive
Platform:
Online, World tenant
Status:
Change type:
Admin impact, New feature, Updated message, User impact
Links:
Details:
Summary:
Custom engine agents will support file uploads from local storage or OneDrive starting mid-December 2025, enabling agents to access files briefly and respond to queries. This applies to all users, requires no admin changes, and expands interaction options beyond text input. Image support will come later.
Details:
Updated November 17, 2025: We have updated the timeline. Thank you for your patience.
Custom engine agents (CEA) are specialized agentic solutions that can be built using any large language model (LLM), toolchain, or orchestration framework, and are tailored to specific domain or tenant workflows. These agents can be created using either Microsoft Copilot Studio or the Agents Toolkit. File upload support is already available in Microsoft 365 Copilot Business Chat.
We're now extending this capability to Custom engine agents, enabling users to upload files stored locally or in OneDrive directly to agents. Once uploaded, agents can access the file for a short duration and respond to user queries based on its contents. This update aligns with customer feedback requesting more flexible input options for agent interactions.
[When this will happen:]
General Availability (Worldwide): Rollout will begin in mid-December 2025 (previously early November) and is expected to complete by late December 2025 (previously late November).
Change Category:
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Scope:
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Release Phase:
Created:
2025-10-25
updated:
2025-11-18
Task Type
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Docu to Check
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MS How does it affect me
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MS Preperations
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MS Urgency
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MS workload name
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summary for non-techies**
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Direct effects for Operations**
File Upload Capability
Users may experience confusion or frustration if they attempt to upload unsupported file types, leading to potential delays in task completion.
- roles: End Users, Helpdesk Staff
- references: https://learn.microsoft.com/microsoft-365-copilot/extensibility/overview-custom-engine-agent
Data Privacy Concerns
Users may be unaware of the temporary storage of uploaded files, raising concerns about data privacy and security, which could lead to reluctance in using the feature.
- roles: End Users, Compliance Officers
- references: https://learn.microsoft.com/microsoft-365-copilot/extensibility/overview-custom-engine-agent
Configutation Options**
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Data Protection**
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explanation for non-techies**
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** AI generated content. This information must be reviewed before use.
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change history
| Date | Property | old | new |
| 2025-11-18 | MC MessageTagNames | New feature, User impact, Admin impact | Updated message, New feature, User impact, Admin impact |
| 2025-11-18 | MC Summary | Custom engine agents will support file uploads from local storage or OneDrive starting November 2025, allowing agents to access files briefly and respond to queries. This feature, enabled by default, applies to all users and matches Copilot's supported file types, with image support coming later. | Custom engine agents will support file uploads from local storage or OneDrive starting mid-December 2025, enabling agents to access files briefly and respond to queries. This applies to all users, requires no admin changes, and expands interaction options beyond text input. Image support will come later. |
| 2025-11-18 | MC Last Updated | 10/25/2025 00:13:16 | 2025-11-17T18:00:23Z |
| 2025-11-18 | MC Messages | Custom engine agents (CEA) are specialized agentic solutions that can be built using any large language model (LLM), toolchain, or orchestration framework, and are tailored to specific domain or tenant workflows. These agents can be created using either Microsoft Copilot Studio or the Agents Toolkit. File upload support is already available in Microsoft 365 Copilot Business Chat.
We're now extending this capability to Custom engine agents, enabling users to upload files stored locally or in OneDrive directly to agents. Once uploaded, agents can access the file for a short duration and respond to user queries based on its contents. This update aligns with customer feedback requesting more flexible input options for agent interactions. [When this will happen:] General Availability (Worldwide): Rollout will begin in early November 2025 and is expected to complete by late November 2025. | Updated November 17, 2025: We have updated the timeline. Thank you for your patience.
Custom engine agents (CEA) are specialized agentic solutions that can be built using any large language model (LLM), toolchain, or orchestration framework, and are tailored to specific domain or tenant workflows. These agents can be created using either Microsoft Copilot Studio or the Agents Toolkit. File upload support is already available in Microsoft 365 Copilot Business Chat. We're now extending this capability to Custom engine agents, enabling users to upload files stored locally or in OneDrive directly to agents. Once uploaded, agents can access the file for a short duration and respond to user queries based on its contents. This update aligns with customer feedback requesting more flexible input options for agent interactions. [When this will happen:] General Availability (Worldwide): Rollout will begin in mid-December 2025 (previously early November) and is expected to complete by late December 2025 (previously late November). |
| 2025-11-18 | MC Title | Microsoft Custom engine agents: Introducing file upload support | (Updated) Microsoft Custom engine agents: Introducing file upload support |
| 2025-11-18 | MC End Time | 01/01/2026 09:00:00 | 2026-02-02T09:00:00Z |
Last updated 3 weeks ago ago
