integrate-graph-api

Integrate Microsoft Graph API

Guide for working with Microsoft Graph API to access Microsoft 365 data.

When to Use

• Accessing user email and messages
• Reading and managing calendar events
• Getting organizational hierarchy and user profiles
• Sending emails on behalf of users

Authentication Setup

App Registration

1. Register app in Azure AD
2. Configure API permissions (Mail.Read, Calendars.ReadWrite, User.Read, etc.)
3. Get client ID, tenant ID, and client secret

Authentication Flow

var scopes = new[] { "https://graph.microsoft.com/.default" };
var options = new TokenCredentialOptions
{
    AuthorityHost = AzureAuthorityHosts.AzurePublicCloud
};

var clientSecretCredential = new ClientSecretCredential(
    tenantId, clientId, clientSecret, options);

var graphClient = new GraphServiceClient(clientSecretCredential, scopes);

Common Operations

Email Operations

List Messages

var messages = await graphClient.Users[userId]
    .Messages
    .Request()
    .Select("id,subject,from,receivedDateTime,bodyPreview")
    .Filter($"receivedDateTime ge {sinceDate:o}")
    .OrderBy("receivedDateTime desc")
    .Top(50)
    .GetAsync();

Send Email

var message = new Message
{
    Subject = subject,
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = htmlBody
    },
    ToRecipients = recipients.Select(r => new Recipient
    {
        EmailAddress = new EmailAddress { Address = r }
    }).ToList()
};

await graphClient.Users[userId]
    .SendMail(message, saveToSentItems: true)
    .Request()
    .PostAsync();

Calendar Operations

Get Calendar Events

var events = await graphClient.Users[userId]
    .CalendarView
    .Request()
    .Header("Prefer", "outlook.timezone=\"UTC\"")
    .Select("id,subject,start,end,attendees,location")
    .Top(100)
    .GetAsync(startDateTime, endDateTime);

Create Calendar Event

var newEvent = new Event
{
    Subject = subject,
    Start = new DateTimeTimeZone
    {
        DateTime = startTime.ToString("o"),
        TimeZone = "UTC"
    },
    End = new DateTimeTimeZone
    {
        DateTime = endTime.ToString("o"),
        TimeZone = "UTC"
    },
    Attendees = attendees.Select(a => new Attendee
    {
        EmailAddress = new EmailAddress { Address = a.Email, Name = a.Name },
        Type = AttendeeType.Required
    }).ToList()
};

await graphClient.Users[userId]
    .Events
    .Request()
    .AddAsync(newEvent);