Microsoft Graph API Integration for Office Add-ins
Connect your Office add-in to Microsoft 365 data via the Graph API. We handle app registration, permissions, OAuth 2.0 flows, and the Graph calls that put email, calendar, OneDrive, and Teams data inside your add-in.
Integration at a Glance
250+ Projects
delivered across integration builds
7 Integration Types
SAP, AI, CRM, Power BI and more
5+ Years
building Office add-in integrations
Free Discovery Call
to scope your integration project
What We Build Into Your Microsoft Graph API Integration
Azure App Registration
We register your add-in in Microsoft Entra ID, configure the correct redirect URIs, and set up the app manifest so Office recognises your add-in and SSO works correctly.
Delegated & Application Permissions
We choose the right Graph permission type for your scenario: delegated permissions when the add-in acts as the signed-in user, application permissions for background or admin-level access.
OAuth 2.0 & MSAL Implementation
We implement the correct auth flow inside Office.js using MSAL, handle the SSO getAccessToken call, and build the fallback dialog for environments where SSO is unavailable.
Email & Calendar Access
We connect add-ins to Graph mail and calendar endpoints: reading messages, creating events, logging activity, and syncing data between your system and the user's Microsoft 365 account.
OneDrive & SharePoint File Access
We build Graph calls that read, write, and manage files in OneDrive and SharePoint directly from Excel, Outlook, or Word add-ins.
Admin Consent Configuration
We configure the admin consent workflow so IT administrators can approve Graph permissions for your add-in during deployment, required for any permission that accesses org-wide data.
Teams & User Profile Data
We access Teams channels, chats, and user profile data via Graph so your add-in can surface org context such as reporting lines, group membership, and presence inside Office.
Token Caching & Refresh Logic
We build server-side token caching and automatic refresh so users authenticate once and the add-in stays connected without interruption across long working sessions.
How the Integration Project Works
- 1
Scope & Permissions Review
We map exactly which Microsoft 365 data your add-in needs to access, such as mail, calendar, files, users, and groups, and identify the minimum Graph permissions required. Least privilege is not optional; AppSource and enterprise IT teams both enforce it.
- 2
Azure App Registration
We register the add-in in Microsoft Entra ID, configure redirect URIs, set up the app manifest for Office SSO, and add the correct Graph API permissions with the right delegated or application permission type.
- 3
Auth Flow Implementation
We implement the OAuth 2.0 flow using MSAL inside the add-in: SSO via getAccessToken where supported, a fallback dialog for older Office versions, and the On-Behalf-Of flow on the server side for Graph calls that require a user token.
- 4
Graph API Build & Testing
We build and test the Graph calls your add-in needs, such as reading mail, writing calendar events, accessing files, and querying user data, against a real Microsoft 365 tenant before any production deployment.
- 5
Admin Consent & Deployment
We configure the admin consent redirect so IT administrators can approve permissions during rollout via Microsoft Admin Center. We document all Graph scopes requested so your client's security team can review before approving.
Microsoft Graph API Integration: Common Questions
Graph gives your add-in access to email, calendar, OneDrive files, SharePoint lists, Teams data, and user profiles, all through a single REST API. If your add-in needs to read or write anything in Microsoft 365, Graph is the connection layer.
Ready to Connect Microsoft Graph API to Microsoft 365?
We scope every integration project on a free discovery call. No commitment, just a clear picture of what the build involves and what it will cost.