Microsoft Graph Subscriptions

Microsoft Graph Subscriptions let your app receive near real-time change notifications (webhooks) when Microsoft 365 data changessuch as Outlook mail and calendar items, users and groups, files in OneDrive/SharePoint, or Teams chats and channels. You register a subscription that specifies the resource to watch and a publicly reachable HTTPS endpoint; Microsoft Graph validates the endpoint and then posts notifications whenever relevant items are created, updated, or deleted. Subscriptions are time-limited and must be renewed, and notifications include information your app can use to verify authenticity and correlate events. You can receive a lightweight payload and fetch details via Graph, or include encrypted resource data directly in the notification. This enables reactive apps, workflows, and sync processes that trigger immediately on changes across Microsoft 365.