Stripe bought Metronome as part of a run of AI-economy infrastructure deals (alongside Bridge and Privy). Stripe's August 19, 2026 investor letter listed Metronome under usage management, said it is used by Anthropic, Nvidia, and other industry leaders, and argued that metered billing in an AI context is inseparable from token serving and consumption. For builders, it is the invoicing layer next to a router such as OpenRouter, not a model API.