AWS ships per-IAM-principal Bedrock cost attribution via CUR 2.0 — with a row-explosion warning

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Part 2 of AWS's cost attribution series (August 12, 2026) shows how CUR 2.0 caller-identity allocation populates a `line_item_iam_principal` column and surfaces `iamPrincipal/`-prefixed tags, letting teams trace each Bedrock inference request to the principal that made it for chargeback. CUDOS dashboard v5.8 adds a Bedrock section under the AI/ML tab with cost-per-million-tokens trends and drill-down without SQL. The gotcha worth knowing before enabling it: 'usage that was previously a single row is now expanded into multiple rows, one for each IAM principal,' inflating CUR file sizes — and Athena bills $5 per TB scanned.