Start Investigation API

Applies to:

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If you are a US Government customer, please use the URIs listed in Microsoft Defender for Endpoint for US Government customers.


For better performance, you can use server closer to your geo location:


API description

Start automated investigation on a device.

See Overview of automated investigations for more information.


  1. Rate limitations for this API are 50 calls per hour.

Requirements for AIR

Your organization must have Defender for Endpoint (see Minimum requirements for Microsoft Defender for Endpoint.

Currently, AIR only supports the following OS versions:

  • Windows Server 2019
  • Windows Server 2022
  • Windows 10, version 1709 (OS Build 16299.1085 with KB4493441) or later
  • Windows 10, version 1803 (OS Build 17134.704 with KB4493464) or later
  • Windows 10, version 1803 or later
  • Windows 11


One of the following permissions is required to call this API. To learn more, including how to choose permissions, see Use Microsoft Defender for Endpoint APIs

Permission type Permission Permission display name
Application Alert.ReadWrite.All 'Read and write all alerts'
Delegated (work or school account) Alert.ReadWrite 'Read and write alerts'


When obtaining a token using user credentials:

  • The user needs to have at least the following role permission: 'Active remediation actions' (See Create and manage roles for more information)
  • The user needs to have access to the device, based on device group settings (See Create and manage device groups for more information)

Device group creation is supported in Defender for Endpoint Plan 1 and Plan 2.

HTTP request


Request headers

Name Type Description
Authorization String Bearer {token}. Required.
Content-Type string application/json. Required.

Request body

In the request body, supply a JSON object with the following parameters:

Parameter Type Description
Comment String Comment to associate with the action. Required.


If successful, this method returns 201 - Created response code and Investigation in the response body.



Here is an example of the request.

  "Comment": "Test investigation"


Do you want to learn more? Engage with the Microsoft Security community in our Tech Community: Microsoft Defender for Endpoint Tech Community.