Overview of the Microsoft 365 Copilot Chat API (preview)

The Microsoft 365 Copilot APIs provide access to components that power Copilot experiences, unlocking the ability to enhance your custom engine agents and generative AI solutions with Microsoft 365 Copilot capabilities. The Microsoft 365 Copilot Chat API allows you to programmatically engage in multi-turn conversations with Microsoft 365 Copilot while using enterprise search grounding and web search grounding.

Why use the Chat API?

The Chat API offers a secure and compliant way to integrate Microsoft 365 Copilot in your custom generative AI solutions. Thus, you don't need to egress data, break permissions, or compromise on security and compliance. Rather than building and maintaining separate vector indexes, large-language models, and orchestration layers, custom applications can hand off prompts to the Chat API and receive fully synthesized answers grounded in web and work data.

Manage compliance and safety risks

The Chat API uses the built-in security and compliance features in Microsoft 365 to ensure that data source permissions and compliance settings are preserved. As a result, using the Chat API prevents data leaks and ensures that sensitive information from one client is never accessible to another, which is essential for maintaining strict security and compliance standards. Within an organization, the permissions model in Microsoft 365 ensures that individuals can only get results from the content they're allowed to access.

Solve for relevancy and freshness

Because the Chat API uses enterprise search grounding in place, its answers are always fresh and relevant. It eliminates the need to maintain separate, costly data pipelines or orchestrators that don't fully understand Microsoft 365 context and signals.

Lower cost of ownership and development effort

The Chat API eliminates the need to maintain a custom orchestration layer or build a secure data export and indexing pipeline that can incur significant costs for organizations.

Chat API capabilities

The Chat API can use the following capabilities to answer natural language prompts:

• Enterprise search grounding
• Web search grounding

The API supports natural language prompts and uses the Microsoft 365 Copilot stack to return relevant answers, all within the Microsoft 365 trust boundary. In addition, the Chat API allows you to provide your OneDrive and SharePoint files as context and toggle web search grounding. These options give you more control over how the Chat API addresses your prompts.

Licensing

The Chat API is available at no extra cost to users with a Microsoft 365 Copilot add-on license. Support for users without a Microsoft 365 Copilot add-on license isn't currently available.

Known limitations

The following are the known limitations to the Chat API:

• The Chat API doesn't support action or content generation skills like creating files, sending emails, or scheduling meetings.
• The Chat API only responds with textual responses.
• The Chat API doesn't support tools such as code interpreter and graphic art.
• The Chat API doesn't support long running tasks. Chat messages that include long running tasks are prone to gateway timeouts.
• The Chat API uses both enterprise search grounding and web search grounding by default.
• Toggling off web search grounding is a single-turn action; this means that web search grounding must be toggled off for each chat message where it isn't required.
• The Chat API is subject to all limitations of the Microsoft 365 Copilot semantic index.
• The Chat API returns AI-generated responses. AI-generated content might be inaccurate, so it should be verified before use.
• Graph explorer doesn't support streamed conversations with the Chat API.

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