Calendar API for Microsoft 365 (Office) calendar integration

The Nylas Calendar API abstracts away the complexity of syncing your application with your users’ Microsoft 365 calendars (formerly Office 365), and every other major calendar provider, making it simple and fast for your users to schedule events.

Calendar Integration
Background Image
const Nylas = require('nylas');
    clientId: CLIENT_ID,
    clientSecret: CLIENT_SECRET,
const nylas = Nylas.with(ACCESS_TOKEN);{calendar_id:, limit: 10 }).then(events => {
    for (let event of events) {
            `Title: ${event.title}`
public class Calendar { 
  public static void main (String[] args) throws Exception {
    NylasAccount account = new NylasClient().account(ACCESS_TOKEN);
    List events =
      new EventQuery().title("Birthday Party!")); Event event ) -> {
      System.out.println( event.getLocation() ); 
from nylas import APIClient
nylas = APIClient(
events =
for event in events:
    print("Title: {} | When: {} | Participants: {}".format(
        event.title, event.when, event.participants
require 'nylas'
nylas =
   client_id: CLIENT_ID,
   client_secret: CLIENT_SECRET,
   access_token: ACCESS_TOKEN
# Most user accounts have multiple calendars where events are stored
calendars = nylas.calendars
calendars.each{ |calendar|
        "Name: #{}   

Integrate Microsoft 365 (Office 365) calendars maintenance-free

Nylas APIs handle every new feature roll-out and bug fix from the Microsoft (Office) 365 APIs. Sync calendar events into your application in real-time and get bi-directional sync with full CRUD (create, read, update, delete).

Nylas’ well-architectured infrastructure delivers over 99.9% availability with no maintenance downtime. Auto-scale your infrastructure as your business grows and reduce the risk of reliance on calendar integration experts.

Integrate with Microsoft 365 (Office 365) calendars in a fraction of the time

When integrating users’ Google Calendars into your app, there are a host of challenges the Nylas Calendar API solves for you, including:

Application integration

Free-busy endpoint

Streamline scheduling by querying free/busy information for a calendar during a certain time without compromising sensitive information about events, like the location.


Recurring events

Support for creating, updating, and deleting recurring events so your users can easily schedule recurring meetings.

Customizable scheduling

Fully own your application scheduling experience by giving your developers the flexibility to quickly build customizable workflows for your users.

Build for free

Unlock your potential with Nylas and start building for free today. Experience the power of our robust APIs to streamline your development process and maintenance with integrations across providers.

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Let our experts help you build a best-in-class Microsoft 365 calendar integration

Contact us today for more information, including live demos, implementation options, and pricing details.

Our experts will help you understand:

  • How to easily integrate with the Microsoft 365 calendar
  • What you need to know about the Microsoft authentication process
  • How Nylas helps mitigate the complexity of building and maintaining your calendar integrations

Embed scheduling instantly from any calendar
Save costs integrating with Microsoft 365 calendar integration

As your platform scales and your user base grows, so do costs for maintaining the Microsoft 365 calendar integration on your own. Nylas handles these for you, including costs for:


  • Scalability — as your platform scales and your user base grows, Nylas has the infrastructure to handle increased usage and ensure reliable performance.
  • Resolving breaking changes — Microsoft had 13 calendar updates for its Graph API in 2020 alone
  • Granular scopes — Nylas offers a comprehensive set of granular scopes, allowing you to fine-tune the permissions and access levels for your calendar integration.
  • Troubleshooting Microsoft 365-s — Let Nylas troubleshoot Microsoft 365-specific bugs and challenges that may occur during the integration, ensuring smooth functionality without any hassle on your part.


With Nylas APIs, you can offload the burden of ongoing maintenance tasks. Our APIs come with out-of-the-box security, and we power even more granular scopes than most providers to improve security for your end-users.

Calculate your savings with the Nylas APIs
At Nylas, securing your data is paramount

With robust security measures ingrained into the core of Nylas’ products, you can have peace of mind, knowing that your data is always safeguarded and secure. Data from every calendar you sync is encrypted and isolated with multi-level permission checks. Nylas adheres to SOC 2 Type II, GDPR, HIPAA BAA, HITECH, ISO 27001, and CCPA.

  • Encryption and access control
  • Network transport and storage
  • Infrastructure and physical security
  • Operational security
  • Around-the-clock monitoring
Download the Security Whitepaper
Frequently Asked Questions

What is Microsoft 365 Calendar API integration?

Microsoft 365 Calendar API integration is the process of incorporating the Microsoft 365 Calendar functionality into an application or system using the API. The API allows developers to access and manipulate calendar-related data, such as creating, updating, and retrieving events, managing calendars, and handling notifications.

By integrating the Microsoft 365 Calendar API, developers can enable users to interact with their Microsoft 365 calendars within their applications. This integration empowers users to view, schedule, and manage events and appointments from their Microsoft 365 calendars without switching between different platforms or interfaces.

How do I get started integrating with the Microsoft 365 Calendar API?

To start integrating with the Microsoft 365 Calendar API, first, create a Microsoft 365 developer account. Register your application in the Azure portal to obtain credentials. Implement authentication to get an access token, and use it to make API requests for managing calendar events and performing other operations.

How do I integrate Microsoft 365 Calendar API with my app?

EWS provides a SOAP implementation and C# client library for full access to Exchange calendars, or you can use Nylas to abstract away the complexity and receive a simplified integration process. 

Both APIs organize calendars and events, but Nylas provides a JSON format for easier implementation. With EWS, you need to authenticate the account and handle permissions, whereas Nylas offers hosted authentication for Microsoft accounts. 

For more details on integrating the Microsoft 365 Calendar API with your app, check out our step-by-step blog post.

How do I authenticate and authorize access for Microsoft 365 Calendar API Integration?

To authenticate and authorize access for Microsoft 365 Calendar API integration, you must register your app and obtain credentials from the Azure portal. Use the obtained access token to request API requests to the Microsoft 365 Calendar API, ensuring your app can access the user’s calendar information. Choose an authentication flow for your app, allowing users to log in and grant permission to access their calendar data.

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