SKILL: Creating Agent Users in Microsoft Entra Agent ID

Overview

An agent user is a specialized user identity in Microsoft Entra ID that enables AI agents to act as digital workers. It allows agents to access APIs and services that strictly require user identities (e.g., Exchange mailboxes, Teams, org charts), while maintaining appropriate security boundaries.

Agent users receive tokens with idtyp=user, unlike regular agent identities which receive idtyp=app.

Prerequisites

• A Microsoft Entra tenant with Agent ID capabilities
• An agent identity (service principal of type ServiceIdentity) created from an agent identity blueprint
• One of the following permissions:
  • AgentIdUser.ReadWrite.IdentityParentedBy (least privileged)
  • AgentIdUser.ReadWrite.All
  • User.ReadWrite.All
• The caller must have at minimum the Agent ID Administrator role (in delegated scenarios)

Important: The identityParentId must reference a true agent identity (created via an agent identity blueprint), NOT a regular application service principal. You can verify by checking that the service principal has @odata.type: #microsoft.graph.agentIdentity and servicePrincipalType: ServiceIdentity.

Architecture

Agent Identity Blueprint (application template)
    │
    ├── Agent Identity (service principal - ServiceIdentity)
    │       │
    │       └── Agent User (user - agentUser) ← 1:1 relationship
    │
    └── Agent Identity Blueprint Principal (service principal in tenant)

Step 1: Verify the Agent Identity Exists

Before creating an agent user, confirm the agent identity is a proper agentIdentity type:

GET https://graph.microsoft.com/beta/servicePrincipals/{agent-identity-id}
Authorization: Bearer <token>

Verify the response contains:

{
  "@odata.type": "#microsoft.graph.agentIdentity",
  "servicePrincipalType": "ServiceIdentity",
  "agentIdentityBlueprintId": "<blueprint-id>"
}

PowerShell

Connect-MgGraph -Scopes "Application.Read.All" -TenantId "<tenant>" -UseDeviceCode -NoWelcome
Invoke-MgGraphRequest -Method GET `
  -Uri "https://graph.microsoft.com/beta/servicePrincipals/<agent-identity-id>" | ConvertTo-Json -Depth 3

Common mistake: Using an app registration's appId or a regular application service principal's id will fail. Only agent identities created from blueprints work.

Step 2: Create the Agent User

HTTP Request

POST https://graph.microsoft.com/beta/users/microsoft.graph.agentUser
Content-Type: application/json
Authorization: Bearer <token>

{
  "accountEnabled": true,
  "displayName": "My Agent User",
  "mailNickname": "my-agent-user",
  "userPrincipalName": "my-agent-user@yourtenant.onmicrosoft.com",
  "identityParentId": "<agent-identity-object-id>"
}

Required Properties

PowerShell

Connect-MgGraph -Scopes "User.ReadWrite.All" -TenantId "<tenant>" -UseDeviceCode -NoWelcome

$body = @{
  accountEnabled    = $true
  displayName       = "My Agent User"
  mailNickname      = "my-agent-user"
  userPrincipalName = "my-agent-user@yourtenant.onmicrosoft.com"
  identityParentId  = "<agent-identity-object-id>"
} | ConvertTo-Json

Invoke-MgGraphRequest -Method POST `
  -Uri "https://graph.microsoft.com/beta/users/microsoft.graph.agentUser" `
  -Body $body -ContentType "application/json" | ConvertTo-Json -Depth 3

Key Notes

• No password — agent users cannot have passwords. They authenticate via their parent agent identity's credentials.
• 1:1 relationship — each agent identity can have at most one agent user. Attempting to create a second returns 400 Bad Request.
• The userPrincipalName must be unique. Don't reuse an existing user's UPN.

Step 3: Assign a Manager (Optional)

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