azureblog.co.uk
← cd ~/graph-permissions
// graph-permissions · ChannelMessage

ChannelMessage.Read.AllMicrosoft Graph permission · High risk

Allows the app to read all channel messages in Microsoft Teams

Application permission

High risk

Read all channel messages. Allows the app to read all channel messages in Microsoft Teams

ID7b2449af-6ccd-4f4d-9f78-e550c193f0d1
ConsentAlways needs admin consent
RiskAs an application permission this reaches every user's data in the tenant, without anyone signed in.

Delegated permission

Medium risk

Read user channel messages. Allows an app to read a channel's messages in Microsoft Teams, on behalf of the signed-in user.

ID767156cb-16ae-4d10-8f8b-41b657c8c8c8
ConsentNeeds admin consent
RiskReads or changes the signed-in user's content, limited to what that user can access.

Grant it to an app

In the portal: App registrations › your app › API permissions › Add a permission › Microsoft Graph › Application permissions, then grant admin consent. Or with Graph PowerShell:

powershell5 lines
Connect-MgGraph -Scopes "Application.Read.All", "AppRoleAssignment.ReadWrite.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
$app   = Get-MgServicePrincipal -Filter "appId eq '<your app's client id>'"
New-MgServicePrincipalAppRoleAssignment -ServicePrincipalId $app.Id `
    -PrincipalId $app.Id -ResourceId $graph.Id -AppRoleId "7b2449af-6ccd-4f4d-9f78-e550c193f0d1"

Ask for it when signing in

Delegated permissions act as the signed-in user, so the app can never do more than that user can.

powershell1 line
Connect-MgGraph -Scopes "ChannelMessage.Read.All"

Which apps already have it?

powershell6 lines
# Apps that hold ChannelMessage.Read.All as an application permission
Connect-MgGraph -Scopes "Application.Read.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
Get-MgServicePrincipalAppRoleAssignedTo -ServicePrincipalId $graph.Id -All |
    Where-Object AppRoleId -eq "7b2449af-6ccd-4f4d-9f78-e550c193f0d1" |
    Select-Object PrincipalDisplayName, PrincipalId, CreatedDateTime
powershell6 lines
# Apps with delegated consent for ChannelMessage.Read.All
Connect-MgGraph -Scopes "Application.Read.All", "Directory.Read.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
Get-MgOauth2PermissionGrant -All |
    Where-Object { $_.ResourceId -eq $graph.Id -and ($_.Scope -split " ") -contains "ChannelMessage.Read.All" } |
    Select-Object ClientId, ConsentType, PrincipalId

Other ChannelMessage permissions

Check every app in your tenant → Permission explainer

Sources