
Access the data and intelligence in Microsoft 365, Windows 10, and Enterprise Mobility.
Microsoft Graph API is a free Social API that requires OAuth authentication, is served over HTTPS and has unconfirmed CORS support.
Find reference content for Microsoft Graph REST APIs in the v1.0 endpoint, which includes APIs in general availability (GA) status.
Details from docs.microsoft.com.

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The Microsoft Graph API is provided by Microsoft Learn (docs.microsoft.com). Find reference content for Microsoft Graph REST APIs in the v1.0 endpoint, which includes APIs in general availability (GA) status.
Yes. The Microsoft Graph API is listed in the Social category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The Microsoft Graph API uses OAuth authentication, so you need to register for credentials before making requests.
CORS support for the Microsoft Graph API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Microsoft Graph API is served over HTTPS, so it's safe to use in production.