Use this to create the App for the Tenantid\clientid and ClientSecret

# Define variables with your values
$tenantId = "xxxx"
$clientId = "xxxxx"
$clientSecret = "xxxxxx"
$outputFile = "C:\Temp\AllGenerativeAIUsage.csv"

# Function to get an access token
function Get-AccessToken {
    param (
        [string]$TenantId,
        [string]$ClientId,
        [string]$ClientSecret
    )
    $tokenUrl = "https://login.microsoftonline.com/$TenantId/oauth2/v2.0/token"
    $body = @{
        grant_type    = "client_credentials"
        client_id     = $ClientId
        client_secret = $ClientSecret
        scope         = "https://graph.microsoft.com/.default"
    }
    try {
        $tokenResponse = Invoke-RestMethod -Uri $tokenUrl -Method Post -Body $body
        Write-Host "Access Token obtained successfully."
        return $tokenResponse.access_token
    } catch {
        Write-Error "Failed to obtain access token: $_"
        exit
    }
}

# Get the access token
$accessToken = Get-AccessToken -TenantId $tenantId -ClientId $clientId -ClientSecret $clientSecret
$headers = @{
    "Authorization" = "Bearer $accessToken"
    "Content-Type"  = "application/json"
}

# Get all streams
$streamsUrl = "https://graph.microsoft.com/beta/security/dataDiscovery/cloudAppDiscovery/uploadedStreams"
try {
    $streamsResponse = Invoke-RestMethod -Uri $streamsUrl -Headers $headers -Method Get
    Write-Host "Streams found: $($streamsResponse.value.Count)"
} catch {
    Write-Error "Failed to retrieve streams: $_"
    exit
}

# Initialize an array to store results
$results = @()

# Loop through each stream to find Generative AI apps
foreach ($stream in $streamsResponse.value) {
    $streamId = $stream.id
    $streamName = $stream.displayName
    Write-Host "Checking stream: $streamName (ID: $streamId)"

    # Get all discovered apps for the stream (last 90 days) with pagination
    $appsUrl = "https://graph.microsoft.com/beta/security/dataDiscovery/cloudAppDiscovery/uploadedStreams/$streamId/aggregatedAppsDetails(period=duration'P90D')"
    $allApps = @()
    $nextLink = $appsUrl
    while ($nextLink) {
        try {
            $response = Invoke-RestMethod -Uri $nextLink -Headers $headers -Method Get
            $allApps += $response.value
            $nextLink = $response.'@odata.nextLink'
            Write-Host "Fetched $($allApps.Count) apps so far for stream ${streamName}..."
        } catch {
            Write-Warning "Failed to retrieve apps for stream ${streamName}: $_"
            $nextLink = $null
        }
    }
    Write-Host "Total apps found in stream ${streamName}: $($allApps.Count)"

    # Filter for Generative AI category or ChatGPT/OpenAI by name/domain
    foreach ($app in $allApps) {
        $appId = $app.id
        $appName = $app.displayName
        $appCategory = $app.category
        $appDomain = $app.domain
        if ($appCategory -ieq "generativeAi" -or $appName -match "ChatGPT" -or $appName -match "OpenAI" -or $appDomain -match "openai.com") {
            Write-Host "Generative AI app found in stream ${streamName}: $appName (ID: $appId, Category: $appCategory, Domain: $appDomain)"
            $usersUrl = "$appsUrl/$appId/users"
            try {
                $usersResponse = Invoke-RestMethod -Uri $usersUrl -Headers $headers -Method Get
                Write-Host "Users found for ${appName}: $($usersResponse.value.Count)"
                if ($usersResponse.value.Count -gt 0) {
                    Write-Host "Usernames: $($usersResponse.value.userIdentifier -join ', ')"
                }
                foreach ($user in $usersResponse.value) {
                    $results += [PSCustomObject]@{
                        Stream        = $streamName
                        AppName       = $appName
                        Username      = $user.userIdentifier
                        ActivityCount = $user.activityCount
                    }
                }
            } catch {
                Write-Warning "Failed to retrieve users for $appName in stream ${streamName}: $_"
            }
        }
    }
}

# Export results to CSV
if ($results.Count -gt 0) {
    $results | Export-Csv -Path $outputFile -NoTypeInformation
    Write-Host "Generative AI usage exported to $outputFile with $($results.Count) entries."
} else {
    Write-Host "No Generative AI usage data found to export across all streams."
}