---
name: reference_investigator_exo_manageasapp_gap
description: Why the remediation-tool investigator-exo tier 401s on EXO adminapi; use exchange-op instead
metadata:
  type: reference
---

The **Security Investigator** app (`bfbc12a4-f0dd-4e12-b06d-997e7271e10c`) registration grants only the `full_access_as_app` (EWS) Office 365 Exchange Online app role — it is **missing `Exchange.ManageAsApp`**. The EXO REST admin API (`outlook.office365.com/adminapi/beta/{tid}/InvokeCommand` — Get-Mailbox, Get-InboxRule, Search-UnifiedAuditLog, etc.) requires `Exchange.ManageAsApp`, so the `investigator-exo` token returns **401** on every cmdlet.

The Exchange Administrator **directory role** is NOT the cause — it is already assigned to the Investigator SP. The gap is the **API permission** on the app registration, which is a manual Entra portal change (suite rule: app registrations stay manual) and arguably shouldn't be added to the read-only Investigator at all.

**How to apply:** for any EXO `InvokeCommand` work (mailbox reads, inbox rules, message trace, TABL, audit), use the **`exchange-op`** tier — the **Exchange Operator** app (`b43e7342-5b4b-492f-890f-bb5a4f7f40e9`) carries BOTH `full_access_as_app` and `Exchange.ManageAsApp`. Don't waste a round trip on `investigator-exo` for adminapi. See [[reference_tedards_tenant_facts]].
