The MCP Cost Ledger: FinOps Billing for 47 AI Agents Without a Tag Schema

The 47th agent is when finance shows up. Below 30 agents in production, the Anthropic invoice is one tolerable line item somewhere south of $25,000 a month, and nobody asks who is spending what. Past 30, the line item crosses $25k. By 47, the median fleet I see at ZopDev customers is at $80,000 a month, and finance walks into the next budget review with a single question: which agent. Nobody can answer it. The cost dashboard buckets spend by AWS account, by team, by service, by tag. None of thos