williamlimasilva/entra-agent-user

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.

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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.

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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)

| Component | Type | Token Claim | Purpose | |---|---|---|---| | Agent Identity | Service Principal | idtyp=app | Backend/API operations | | Agent User | User (agentUser) | idtyp=user | Act as a digital worker in M365 |

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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.

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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": "[email protected]",
  "identityParentId": "<agent-identity-object-id>"
}

Required Properties

| Property | Type | Description | |---|---|---| | accountEnabled | Boolean | true to enable the account | | displayName | String | Human-friendly name | | mailNickname | String | Mail alias (no spaces/special chars) | | userPrincipalName | String | UPN — must be unique in the tenant (alias@verified-domain) | | identityParentId | String | Object ID of the parent agent identity |

PowerShell

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

$body = @{
  accountEnabled    = $true
  displayName       = "My Agent User"
  mailNickname      = "my-agent-user"
  userPrincipalName = "[email protected]"
  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.

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Step 3: Assign a Manager (Optional)

Assigning a manager allows the agent user to appear in org charts (e.g., Teams).

PUT https://graph.microsoft.com/beta/users/{agent-user-id}/manager/$ref
Content-Type: application/json
Authorization: Bearer <token>

{
  "@odata.id": "https://graph.microsoft.com/beta/users/{manager-user-id}"
}

PowerShell

$managerBody = '{"@odata.id":"https://graph.microsoft.com/beta/users/<manager-user-id>"}'
Invoke-MgGraphRequest -Method PUT `
  -Uri "https://graph.microsoft.com/beta/users/<agent-user-id>/manager/`$ref" `
  -Body $managerBody -ContentType "application/json"

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Step 4: Set Usage Location and Assign Licenses (Optional)

A license is needed for the agent user to have a mailbox, Teams presence, etc. Usage location must be set first.

Set Usage Location

PATCH https://graph.microsoft.com/beta/users/{agent-user-id}
Content-Type: application/json
Authorization: Bearer <token>

{
  "usageLocation": "US"
}

List Available Licenses

GET https://graph.microsoft.com/beta/subscribedSkus?$select=skuPartNumber,skuId,consumedUnits,prepaidUnits
Authorization: Bearer <token>

Requires Organization.Read.All permission.

Assign a License

POST https://graph.microsoft.com/beta/users/{agent-user-id}/assignLicense
Content-Type: application/json
Authorization: Bearer <token>

{
  "addLicenses": [
    { "skuId": "<sku-id>" }
  ],
  "removeLicenses": []
}

PowerShell (all in one)

Connect-MgGraph -Scopes "User.ReadWrite.All","Organization.Read.All" -TenantId "<tenant>" -NoWelcome

# Set usage location
Invoke-MgGraphRequest -Method PATCH `
  -Uri "https://graph.microsoft.com/beta/users/<agent-user-id>" `
  -Body '{"usageLocation":"US"}' -ContentType "application/json"

# Assign license
$licenseBody = '{"addLicenses":[{"skuId":"<sku-id>"}],"removeLicenses":[]}'
Invoke-MgGraphRequest -Method POST `
  -Uri "https://graph.microsoft.com/beta/users/<agent-user-id>/assignLicense" `
  -Body $licenseBody -ContentType "application/json"

Tip: You can also assign licenses via the Entra admin center under Identity → Users → All users → select the agent user → Licenses and apps.

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Provisioning Times

| Service | Estimated Time | |---|---| | Exchange mailbox | 5–30 minutes | | Teams availability | 15 min – 24 hours | | Org chart / People search | Up to 24–48 hours | | SharePoint / OneDrive | 5–30 minutes | | Global Address List | Up to 24 hours |

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Agent User Capabilities

• ✅ Added to Microsoft Entra groups (including dynamic groups)
• ✅ Access user-only APIs (idtyp=user tokens)
• ✅ Own a mailbox, calendar, and contacts
• ✅ Participate in Teams chats and channels
• ✅ Appear in org charts and People search
• ✅ Added to administrative units
• ✅ Assigned licenses

Agent User Security Constraints

• ❌ Cannot have passwords, passkeys, or interactive sign-in
• ❌ Cannot be assigned privileged admin roles
• ❌ Cannot be added to role-assignable groups
• ❌ Permissions similar to guest users by default
• ❌ Custom role assignment not available

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Troubleshooting

| Error | Cause | Fix | |---|---|---| | Agent user IdentityParent does not exist | identityParentId points to a non-existent or non-agent-identity object | Verify the ID is an agentIdentity service principal, not a regular app | | 400 Bad Request (identityParentId already linked) | The agent identity already has an agent user | Each agent identity supports only one agent user | | 409 Conflict on UPN | The userPrincipalName is already taken | Use a unique UPN | | License assignment fails | Usage location not set | Set usageLocation before assigning licenses |

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References

• Agent identities
• Agent users
• Agent service principals
• Create agent identity blueprint
• Create agent identities
• agentUser resource type (Graph API)
• Create agentUser (Graph API)