azure-cost

Use the Cost Management Query API via az rest with a POST to {scope}/providers/Microsoft.CostManagement/query. Specify a dataset with aggregation on Cost and grouping by ServiceName or ResourceGroupName, with a timeframe like MonthToDate or a custom date range.

Call the Cost Management Forecast API with a Custom timeframe where the to date is in the future. The API requires at least 28 days of historical cost data and supports Daily or Monthly granularity, but does not support grouping.

You need the Cost Management Reader role plus Monitoring Reader and Reader roles on the target scope. Without these, the API returns 403 Forbidden errors.

ResourceId grouping is only supported at subscription and resource group scopes. At billing account, management group, or higher scopes, use ServiceName or SubscriptionName dimensions instead.

Use Azure Resource Graph KQL queries to find unattached managed disks, orphaned NICs, and idle load balancers, or run an Azure Quick Review (azqr) scan. Cross-reference findings with actual cost data before deleting anything.

Limits include 20 requests per minute per user and 4 requests per minute per scope, which is the most restrictive. On a 429 response, check all x-ms-ratelimit retry-after headers and wait for the longest value before retrying, with a maximum of 3 retries.