PowerShell script to read the workspace ids/workspace name from a CSV and add them to FabricCapacity

You can use below script

# Parameters
$csvFilePath = "C:\Path\To\Your\WorkspaceList.csv" # Update the path
$capacityId = "your-fabric-capacity-id" # Update with your Fabric capacity ID

# Authenticate to Power BI (use service principal or interactive login)
$clientId = "your-client-id"
$tenantId = "your-tenant-id"
$clientSecret = "your-client-secret"

$body = @{
resource = "https://graph.microsoft.com/"
client_id = $clientId
client_secret = $clientSecret
grant_type = "client_credentials"
scope = "https://graph.microsoft.com/.default"
}

$tokenResponse = Invoke-RestMethod -Uri "https://login.microsoftonline.com/$tenantId/oauth2/v2.0/token" -Method Post -ContentType "application/x-www-form-urlencoded" -Body $body
$accessToken = $tokenResponse.access_token

# Read CSV File
$workspaces = Import-Csv -Path $csvFilePath

# Function to get workspace ID from workspace name
function Get-WorkspaceId {
param ($workspaceName)
$url = "https://api.powerbi.com/v1.0/myorg/groups"
$headers = @{Authorization = "Bearer $accessToken"}
$response = Invoke-RestMethod -Uri $url -Headers $headers -Method Get
$workspace = $response.value | Where-Object { $_.name -eq $workspaceName }
return $workspace.id
}

# Iterate through workspaces
foreach ($workspace in $workspaces) {
$workspaceId = $workspace.WorkspaceId

# If WorkspaceId is empty, fetch it using WorkspaceName
if (-not $workspaceId -and $workspace.WorkspaceName) {
$workspaceId = Get-WorkspaceId -workspaceName $workspace.WorkspaceName
}

if ($workspaceId) {
$assignUrl = "https://api.powerbi.com/v1.0/myorg/capacities/$capacityId/workloads/assign"
$assignBody = @{
groupId = $workspaceId
} | ConvertTo-Json -Depth 1

$assignHeaders = @{
Authorization = "Bearer $accessToken"
"Content-Type" = "application/json"
}

try {
$response = Invoke-RestMethod -Uri $assignUrl -Headers $assignHeaders -Method Post -Body $assignBody
Write-Output "Successfully added Workspace ID $workspaceId to Fabric capacity."
} catch {
Write-Output "Failed to add Workspace ID $workspaceId. Error: $_"
}
} else {
Write-Output "Workspace not found: $($workspace.WorkspaceName)"
}
}