Integrate the Microsoft 365 API.Caddi writes and runs the integration for you.
Microsoft 365 has a REST API. Self-serve for any developer who registers an app in Microsoft Entra ID, but tenant data needs user consent or admin consent.
- 99%of agent runs complete successfully
- ~45 minon average to build your first agent
- 1M+back-office tasks completed
The connection is a project before it does anything.
Before the first record moves: an app registration, credentials, token refresh, and somewhere to host and monitor the code. No single global limit: throttling thresholds vary by service and scenario (see the service-specific limits page) and return 429 with Retry-After.
Register an app, store Microsoft 365 credentials, refresh tokens and code around the rate limits.
Connect your Microsoft 365 account once. Caddi holds the connection.
The job doesn't stop at Microsoft 365.
An intake, a filing or a client update also runs through email, documents and the other systems your team works in. The Microsoft 365 API only reaches Microsoft 365.
Each extra system is another API, another set of credentials, another integration to own.
One automation runs across every tool the job touches, each through its API.
Someone has to own the code.
API versions change, fields get added and your process moves. Microsoft points large-volume data extraction to Microsoft Graph Data Connect instead of the Graph REST APIs.
A developer patches and redeploys the integration each time.
The person who does the work updates it by showing or describing the change. Every automation is reviewed before it runs in production, and every run is logged.
What the Microsoft 365 API gives you
- Type
- REST (JSON)
- Authentication
- OAuth 2.0 via Microsoft identity platform (Microsoft Entra ID), delegated or application permissions
- Who can get access
- Self-serve for any developer who registers an app in Microsoft Entra ID, but tenant data needs user consent or admin consent.
- What it covers
- Microsoft 365 data including users, groups, Outlook mail/calendar/contacts, OneDrive, SharePoint, Teams, Planner, OneNote, To Do, plus Entra ID and Intune.
- Limits
- No single global limit: throttling thresholds vary by service and scenario (see the service-specific limits page) and return 429 with Retry-After.
- Worth knowing
- Microsoft points large-volume data extraction to Microsoft Graph Data Connect instead of the Graph REST APIs.
Official docs: learn.microsoft.com. Checked September 2026. Vendors change access terms, so confirm with Microsoft 365 before you build.
When to build the Microsoft 365 integration in-house
When you have engineers and the integration is your product, or you need one narrow sync between two systems and someone to own it. When the goal is getting Microsoft 365 work off someone's desk, the build is the slow part, and Caddi does it for you.
What teams usually want the Microsoft 365 API for
New Hire Tracker Cleanup
Caddi manages new hire onboarding follow-ups in an Excel tracker by categorizing employees, updating tracking fields, and removing duplicate entries.
Excel Transaction Sync
Caddi transfers new deal transaction data between Excel worksheets by creating a row for each transaction and mapping source values into the destination sheet.
Onboarding Tracker Cleanup
Caddi manages onboarding follow-ups from an onboarding report by classifying employees, updating tracker fields, and removing duplicate entries.
Outlook → Word → DMS
Caddi reads inbound requests in Outlook, drafts the response document in Word with current data, and files the finalized version in your DMS.
Everything Caddi does with Microsoft 365.
Microsoft 365 API questions
Does Microsoft 365 have an API?
Yes. Microsoft 365 has a REST API, authenticated with OAuth 2.0 via Microsoft identity platform (Microsoft Entra ID), delegated or application permissions. The official documentation is at https://learn.microsoft.com/en-us/graph/overview.
How do I get access to the Microsoft 365 API?
Self-serve for any developer who registers an app in Microsoft Entra ID, but tenant data needs user consent or admin consent.
Does the Microsoft 365 API have rate limits?
No single global limit: throttling thresholds vary by service and scenario (see the service-specific limits page) and return 429 with Retry-After.
Can I connect Microsoft 365 to my other tools without writing code against its API?
Yes. With Caddi you show the Microsoft 365 task once, the way you'd train a new hire, and Caddi builds it as verified code that runs across Microsoft 365 and the other tools the job touches. Steps that need a person's judgment are handed to Copilot or Claude, and Caddi monitors those too.
Do I need a developer to automate Microsoft 365 with Caddi?
No. There is no integration code for you to write or maintain. Every automation Caddi builds for Microsoft 365 is reviewed before it runs in production, and every run is logged.