Microsoft Graph file URL authentication retirement

What changes

Affected Microsoft Graph file APIs will stop embedding authorization in returned URLs. Some calls will stop returning HTTP 302 redirects and return content directly; other SharePoint URLs will require a Microsoft Entra ID token in the Authorization header.

Review download, upload-session, copy and monitor, preview, thumbnail, version, and format-conversion integrations. Applications that store, forward, inspect, or redeem returned URLs as durable access artifacts are at risk.

Discover and validate

• Name the business owner, technical owner, vendor, application ID, affected API, supported version, and production milestone for every integration.
• Search code and configuration for tempauth, access_token, uploadUrl, getUrl, @microsoft.graph.downloadUrl, monitor URLs, and custom HTTP 302 handling. Do not place live tokens or sensitive URLs in the record.
• Confirm the target token audience and permissions. Remove assumptions that returned URLs work without authentication or remain durable.
• Test in a test tenant, one application ID at a time. Exercise retries, large files, token expiry, and permission failures; monitor application errors and Entra sign-in failures.
• Use a controlled rollout and publish the minimum supported vendor or application version before April 1, 2027.

Microsoft's October 8 post gives inconsistent availability wording for the app-scoped tenant setting. Verify the current SharePoint Online PowerShell module and tenant behavior before relying on it.

Microsoft sources

• Microsoft 365 Developer Blog retirement notice — published October 8, 2026.
• Microsoft 365 Message Center MC1492958 — published October 9, 2026; administrator sign-in required.
• Set-SPOTenantPreAuthSettings — verify current parameters before testing.

Test outside production first. Tenant pre-authentication settings and application changes can interrupt file workflows.