Microsoft 365 Developer Blog
A developer platform for building collaborative apps for hybrid work
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From Innovation to Enterprise Trust with Microsoft Agent 365
Agent 365 serves as the control plane for agents, providing organizations with a centralized location to manage agent identity, policies, observability, and lif...
Latest posts
SharePoint Framework (SPFx) roadmap update – December 2025
SPFx is powering the future of Microsoft 365. From AI-driven portals to seamless integrations across SharePoint, Teams and Viva, SPFx is driving innovation at scale. This monthly blog series kicks off our journey into the next evolution - transparent, community-driven, and built for the AI era. Let’s shape what’s next, together.
Unlock your email potential with Schema.org
Email is a key part of how people get things done, whether it’s booking a reservation, confirming a package delivery, or managing a cab reservation. But as inboxes become increasingly cluttered, important transactional information often gets buried. Users are forced to open multiple emails, search through text, and manually look for key details such as reservation times, delivery status, or order confirmations. Let's think about business travel, When users are flying out for meetings, training, or conferences, they shouldn’t have to dig through a crowded inbox to find flight details, hotel confirmations, or car...
Build declarative agents for Microsoft 365 Copilot with MCP
With introduction of MCP support, it’s now much easier for developers to integrate their business workflows, SaaS, and LoB systems into Copilot via declarative agent.
General Availability of SharePoint Framework 1.22 – A Major Refresh of the Build & Tooling Experience
We are excited to announce general availability for the SharePoint Framework 1.22. This time focus is primarily on updating the build toolchain and to address npm audit issues.
Dev Proxy v2.0 with improved AI telemetry, and small breaking changes
Introducing Dev Proxy v2.0 with improved AI telemetry, and small breaking changes.
Introducing TypeSpec for Microsoft 365 Copilot – Build declarative agents faster with more confidence
We’re excited to announce that TypeSpec for Microsoft 365 Copilot is now generally available! This milestone marks the first stable release of the domain-specific language (DSL) designed to streamline how developers build and extend Microsoft 365 Copilot. Whether you’re creating an agent to help colleagues find documents, or connecting your service as an API plugin, TypeSpec for Microsoft 365 Copilot makes the process simpler, safer, and more productive. A developer-centric experience – strong typing, IntelliSense and productivity One of the biggest pain points for developers building Copilot extensibility so...
SharePoint Framework (SPFx) roadmap update – November 2025
SPFx is powering the future of Microsoft 365. From AI-driven portals to seamless integrations across SharePoint, Teams and Viva, SPFx is driving innovation at scale. This monthly blog series kicks off our journey into the next evolution - transparent, community-driven, and built for the AI era. Let’s shape what’s next, together.
SharePoint Site Creation in Microsoft Graph
The SharePoint team is excited to (finally) bring Site Collection creation to Graph! Starting in Microsoft Graph beta you can now create new site collections!
Ignite 2025: A Developer’s Guide to Building Agents for Microsoft 365
Ignite 2025 brought many innovations for developers building agents for Microsoft 365. From new capabilities in Declarative Agents and Custom Engine Agents to the introduction of Microsoft Agent 365, the platform now enables organizations to architect intelligent solutions that are secure, governable, and ready for enterprise scale. Whether you’re creating your first agent, adapting existing frameworks, or navigating a crowded AI landscape, Microsoft 365 empowers you to build agents that integrate deeply with enterprise systems, leverage the latest AI stacks, and meet the highest standards for security and gov...
Microsoft 365 Copilot APIs: What’s New and What’s Next
At Build 2025, we introduced the Microsoft 365 Copilot APIs to help developers bring grounded AI into their solutions without rebuilding indexes or compromising security. The response has been encouraging, and your feedback continues to guide the direction of the platform. Customers are asking for deeper retrieval, better search, and simpler ways to generate answers that honor permissions and context. This Ignite 2025 roadmap update expands the Copilot API surface with new capabilities that make grounded AI more accessible, more reliable, and easier to integrate within the Microsoft 365 trust boundary. Ret...
Ignite 2025 – What’s new for Office Add-ins
Read about new and exciting features now available in the Office Add-ins ecosystem for Ignite 2025. Learn about platform updates, developer experience improvements, and store enhancements.
Microsoft Agent 365 Interoperability for Smart, Secure Productivity
Agent 365 Interoperability equips any agent with apps and data to simplify human-agent workflows.
Announcing the Microsoft Teams SDK (Formerly the Teams AI Library)
Discover the new and improved Teams SDK, designed to help developers create even more powerful agents for Microsoft Teams.
From Innovation to Enterprise Trust with Microsoft Agent 365
Agent 365 serves as the control plane for agents, providing organizations with a centralized location to manage agent identity, policies, observability, and lifecycle.
New developer resource page for Microsoft 365 interoperability and data portability
Microsoft is launching a centralized developer resource page that consolidates interoperability and data portability information, tools, and feedback channels to help partners and customers use Microsoft 365 more effectively.
SharePoint Framework (SPFx) roadmap update – October 2025
SPFx is powering the future of Microsoft 365. From AI-driven portals to seamless integrations across SharePoint, Teams and Viva, SPFx is driving innovation at scale. This blog series kicks off our journey into the next evolution—transparent, community-driven, and built for the AI era. Let’s shape what’s next, together.
Dev Proxy v1.3 with exporting to HAR, LLM usage tracking, and enhanced permissions analysis
Introducing Dev Proxy v1.3 with new plugins for inspecting and debugging API requests, along with enhanced permissions analysis and improved OpenAPI spec generation for complex testing scenarios.
Migrating from IDCRL authentication to modern authentication in SharePoint
In the next few months, Microsoft will be removing the legacy authentication protocol known as IDCRL (Identity Client Run Time Library) in SharePoint.
Deprecation of the previewImageUrl property for Insights items that reference file attachments
The previewImageUrl property is no longer returned for file attachment items.
Exciting new capabilities and enhancements for M365 Developer Program – October 2025
We are excited to share updates on the Microsoft 365 Developer Program with new capabilities and upcoming changes.
Changes to inline image representation in Outlook on the web and new Outlook for Windows
We are updating how inline images are represented in the HTML body of Outlook emails in Outlook on the web and the new Outlook for Windows. This change may impact how your add-in identifies and processes inline images when using the attachment ID.
SharePoint Framework (SPFx) roadmap update – September 2025
SPFx is powering the future of Microsoft 365. From AI-driven portals to seamless integrations across SharePoint, Teams and Viva, SPFx is driving innovation at scale. This new blog series kicks off our journey into the next evolution—transparent, community-driven, and built for the AI era. Let’s shape what’s next, together.
Dev Proxy v1.2 with mock response mirroring and improved performance
Introducing Dev Proxy v1.2 with mock response mirroring capabilities that make API simulation more realistic.
The new GitHub app for Teams: from conversation to code
Meet the reimagined GitHub app for Teams: an AI-powered app to collaborate with GitHub Copilot right inside your Teams conversations.
Excel announces undo support for 3rd-party web add-ins
Most user action performed by your Copilot extension or web add-in can now be undone using the familiar ribbon Undo button, keyboard shortcuts (Ctrl+Z), or the Undo button on Copilot response cards.
Prepare your VBA projects for VBScript deprecation in Windows
In May 2024, Microsoft announced the phased deprecation of VBScript in Windows, as detailed in the official Windows IT Pro Blog. This change impacts VBA developers who rely on VBScript, particularly for reference libraries such as regular expressions. This post outlines the upcoming changes and provides guidance to help you future proof your VBA projects. How VBA projects use VBScript Visual Basic for Applications (VBA) automates tasks and extends functionality in Office applications, including Excel, Word, PowerPoint, and Access. VBScript is commonly used in VBA projects in two ways: VBScript depr...
Change to data visibility for Microsoft Graph callRecords APIs in GCC High and DoD
We're making changes to how Microsoft handles Microsoft Teams call data in GCC High and DoD environments that we expose via the Microsoft Graph callRecords APIs.
Dev Proxy v1.1 with improved support for Microsoft Graph batching
Introducing Dev Proxy v1.1 with critical fixes for Microsoft Graph batch request simulation, resolved authentication plugin issues, and enhanced the MinimalPermissionsGuidancePlugin with new reporting capabilities.
Enriching Microsoft 365 profiles with Microsoft 365 Copilot connectors for people data (public preview)
Enrich Microsoft 365 profiles with Microsoft 365 Copilot connectors for people data
Microsoft Graph Toolkit retirement
We are announcing the deprecation of the Microsoft Graph Toolkit (MGT). The retirement period begins September 1st, 2025 with full retirement planned for August 28th, 2026. Why we’re retiring this toolkit We introduced the Microsoft Graph Toolkit (MGT) to simplify the developer experience when building web applications that connect to Microsoft Graph. It provided a set of reusable web components and helpers to accelerate development and reduce the complexity of authentication and data binding. However, the MGT’s narrower ecosystem, and overlap with more powerful alternatives have led to a decline in its usage o...
Microsoft Graph CLI retirement
We are announcing the retirement of the Microsoft Graph command-line interface (CLI). The Microsoft Graph CLI has served as a powerful tool for developers and IT professionals to interact with Microsoft Graph through simple terminal commands—enabling automation, scripting, and streamlined access to Microsoft 365 data and services. As we evolve our developer tooling strategy, we’re shifting focus to the more integrated and modern experiences found in PowerShell. Why we’re retiring the CLI We introduced the Microsoft Graph CLI to provide a lightweight, cross-platform tool for interacting with Microsoft Graph APIs...
Dev Proxy v1.0 with new features for building robust AI-powered apps
Introducing Dev Proxy v1.0, with new language model-specific testing capabilities to help developers build more reliable AI-powered applications by simulating real-world scenarios and tracking resource usage.
Build Smarter with the Microsoft 365 Agents Toolkit MCP Server
Bring your own agents into Microsoft 365 Copilot
Custom Engine Agents now generally available—build and integrate your own AI into the flow of work Microsoft 365 Copilot is redefining how people interact with AI—embedding it directly into the flow of work as the intuitive, natural interface for agents: the ‘UI for AI’ As Copilot becomes the interface for AI in the workplace, we’re seeing growing demand from customers who want to extend its capabilities with their own solutions. Many of our customers are looking to create custom agents—or have already built agents that operate outside the Microsoft 365 ecosystem—using fine-tuned models, custom logic, orchest...
Supercharge your EWS migration with AI and GitHub Copilot
We're announcing a new tutorial that helps developers migrate solutions from EWS to Microsoft Graph using AI and GitHub Copilot.
Microsoft 365 Copilot APIs: Unlocking enterprise knowledge for AI with the Retrieval API — Now in Public Preview
Read how the Retrieval API gives developers a secure, compliant and scalable way to integrate enterprise content into their AI workflows.
Dev Proxy v0.29 with refactored architecture, MCP server, and exposed LM prompts
Introducing Dev Proxy v0.29, with a major architectural overhaul, control over language model prompts, and improved diagnostics.
Deprecation of MS-APP-ACTS-AS header in Shifts Management Microsoft Graph APIs
In app-only access scenarios, Shifts Management Graph APIs previously required the MS-APP-ACTS-AS: userId header to indicate the user on whose behalf the application was acting. However, this conflicted with the Microsoft Graph permission model where there is no signed-in user for app-only access scenarios. To align Shifts Graph APIs with this model, the MS-APP-ACTS-AS header has now been deprecated. What Action You Need to Take If you don’t send the header today There is no impact. No changes are necessary. If you send the header today 1. Please remove the header. Example: Old: New: ...
Dev Proxy v0.28 with LLM usage and costs tracking
The latest version of Dev Proxy introduces a new ability to help you understand language models’ usage and costs in your applications, alongside many improvements to mocking, TypeSpec generation, and plugin flexibility.
Build like Microsoft: Developer agents in action
Take a deep dive into Athena, an AI-powered collaborative agent, to learn how it was built and how to create your own version of Athena right within Microsoft Teams.
Office Add-ins announces Copilot agents with add-in actions and more at Build 2025
As part of the expanding capabilities for agents across Microsoft 365, Office Platform announces add-in actions for Copilot agents are available in preview. This blog is an overview of all the new capabilities across the platform: APIs, developer tools, and add-in distribution options—making it simpler to build new or iterate on JavaScript add-ins.
Introducing the Agent Store: Build, publish, and discover agents in Microsoft 365 Copilot
We’re excited to introduce the Agent Store — a centralized, curated marketplace that features agents built by Microsoft, trusted partners, and customers. The Agent Store offers a new, immersive experience within Microsoft 365 Copilot that enables users to browse, install, and try agents tailored to their needs.
Introducing the Microsoft 365 Agents Toolkit
Read how the Microsoft 365 Agents Toolkit, an evolution of Microsoft Teams Toolkit, is designed to help developers build agents and apps for Microsoft 365 Copilot, Microsoft Teams, and Microsoft 365.
Introducing Microsoft 365 Copilot APIs
Learn how Microsoft 365 Copilot APIs allow you to build solutions grounded in your organization’s content, context, and permissions, without needing to relocate or duplicate data.
Exchange Web Services code analyzer and usage report
We are less than 18 months away from the retirement of Exchange Web Services. Start planning your migration from EWS to Microsoft Graph.