Microsoft 365 development
Microsoft 365 Development and Integration
Extend Teams, Outlook and Microsoft 365 Copilot with your own apps and data.
Microsoft 365 is where most employees spend their working day. We build Teams apps, Outlook add-ins, Microsoft Graph integrations and Microsoft 365 Copilot extensions, so your business systems and data appear where people already work.
What we cover
- Microsoft Teams apps and bots
- Outlook and Office add-ins
- Microsoft Graph integrations
- Microsoft 365 Copilot extensions
- Entra ID app registration and permissions
- Adaptive Cards and notifications
Requirement-led advice · Documented handover
- Advice based on your requirements
- Works with your existing stack
- Documented, maintainable delivery
What Can You Build on Microsoft 365?
Microsoft 365 combines Teams, Outlook, Word, Excel, SharePoint, OneDrive and Microsoft 365 Copilot, all built on Microsoft Graph, a single API for users, mail, calendars, files, chats and more. Developers can extend each product: Teams apps add tabs, bots and message extensions; Office add-ins add panes and commands to Outlook, Word and Excel; and Graph lets other systems read and write Microsoft 365 data with proper consent.
Microsoft 365 Copilot can be extended with declarative agents, API plugins and Copilot connectors that bring external content into Copilot and Microsoft Search. Every extension uses a Microsoft Entra ID app registration, and the permissions it requests need admin review, so security design is part of the build from the first day.
When Microsoft 365 development is a good fit
- Your staff live in Teams and Outlook, and switching to other systems slows them down.
- Business data should appear in Microsoft 365 Copilot answers.
- You need to automate work with mail, calendars, files or Teams messages.
- You want notifications and approvals delivered in Teams.
What We Build for Microsoft 365
Extensions that bring your systems into the tools people already use.
Teams apps
Tabs, bots and message extensions for internal systems.
Outlook add-ins
Log emails to CRM, look up customers, file attachments.
Copilot extensions
Declarative agents and plugins over your business data.
Copilot connectors
Make external content searchable in Copilot and Microsoft Search.
Notifications
Adaptive Card alerts and approvals in Teams.
Graph integrations
Sync users, calendars and files with other systems.
Document automation
Generate and file Word and Excel documents.
Usage and reporting
Reports on adoption and activity through Graph.
Microsoft 365 Services We Deliver
Each piece of work has a clear output, so you know what you will receive.
Solution design
Choose the right extension type and permissions for each need.
Deliverables: solution design, permission review
Teams app development
Tabs, bots and message extensions with Single Sign-On.
Deliverables: Teams app package, source code
Office add-ins
Outlook, Word and Excel add-ins with centralised deployment.
Deliverables: add-in, deployment guide
Copilot extensibility
Declarative agents, API plugins and Copilot connectors.
Deliverables: agent or plugin package, test results
Graph integration
Services that read and write Microsoft 365 data securely.
Deliverables: integration service, consent documentation
Security and deployment
App registrations, least-privilege permissions and admin rollout.
Deliverables: security notes, rollout plan
Microsoft 365 Developer Platform
Tools and APIs we use.
Surfaces
- Microsoft Teams
- Outlook
- Word and Excel
- Microsoft 365 Copilot
APIs and data
- Microsoft Graph
- Graph change notifications
- Copilot connectors
- SharePoint and OneDrive
Building blocks
- Microsoft 365 Agents Toolkit
- Office Add-ins
- Adaptive Cards
- Bot and agent frameworks
Security
- Microsoft Entra ID app registrations
- Delegated and application permissions
- Admin consent
- Centralised deployment
Listing a feature here does not mean every project uses it. We recommend what fits your requirements, skills, licensing and running costs.
How Microsoft 365 Fits Your Stack
Content and documents usually sit in SharePoint, processes run in Power Automate, and low-code agents come from Copilot Studio. Custom extensions and Graph services are typically built in .NET or TypeScript and hosted on Azure.
When the business data lives in another system, GraphQL or REST APIs and MCP servers can expose it safely to Microsoft 365 and other AI clients.
Implementation Considerations
- Request the fewest Graph permissions needed, and prefer delegated over application access.
- Plan admin consent and app approval with your Microsoft 365 administrators early.
- Respect user permissions when bringing data into Copilot.
- Test on the Teams and Outlook clients your users actually run, including mobile.
- Check Microsoft 365 Copilot licensing for the users who will use extensions.
- Keep tenant settings and app policies documented for support.
How We Work With Microsoft 365
The same four steps we use across our technology work, adapted to your scope.
Discover
Goals, users, constraints and the systems Microsoft 365 must work with.
Select
Confirm Microsoft 365 is the right fit and agree the architecture and scope.
Build and integrate
Deliver in short iterations with testing, reviews and documentation.
Operate and improve
Monitor, support and improve the solution as your needs change.
Microsoft 365 Questions, Answered
What is Microsoft Graph?
A single Microsoft API for Microsoft 365 data such as users, mail, calendars, files and Teams messages.
Can you build apps inside Microsoft Teams?
Yes. Tabs, bots and message extensions, usually with Single Sign-On through Microsoft Entra ID.
Can Microsoft 365 Copilot use data from our own systems?
Yes, through Copilot connectors, declarative agents and API plugins, subject to licensing and permissions.
What is an Outlook add-in?
A web-based extension that adds panes and commands to Outlook on Windows, Mac, web and mobile.
Do these apps need admin approval?
Usually yes, for permissions and deployment. We prepare the documentation your administrators need.
Is SharePoint covered here?
SharePoint has its own page covering intranets, document management and SPFx development.
Extending Microsoft 365?
Tell us which systems and processes you want inside Teams, Outlook or Copilot, and we will suggest an approach.
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