To connect Dex to Microsoft 365, you first register a single Entra ID application that all Microsoft connectors share, then hand Dex its Tenant ID, Client ID, and a Client Secret.
Steps
1Sign in to the Microsoft Entra admin center (entra.microsoft.com) as a Global Administrator or Privileged Role Administrator.
2Go to Entra ID → App registrations → New registration; give it a name (e.g. "Dex Integration"), choose "Single tenant", and click Register.
3On the app's Overview page, copy the Application (client) ID and the Directory (tenant) ID.
4Go to Certificates & secrets → Client secrets → New client secret, set an expiry, click Add, and copy the secret Value immediately.
5Go to API permissions → Add a permission → Microsoft Graph → Application permissions, and add the scopes each connector needs (see the individual connector pages).
6Click "Grant admin consent for <tenant>" and confirm — every permission must show a green check.
Paste into Dex
The connection form in the Dex app store asks for these values:
Directory (tenant) ID
Application (client) ID
Client secret (Value)
Shown only once at creation — copy it immediately.
