I Built a Token Billing System for My AI Agent - Here's How It Works

A developer building an AI agent that routes requests across multiple LLM providers faced fair pricing challenges, as flat subscriptions didn't account for varying token costs between models. They implemented Kong AI Gateway with Konnect Metering & Billing, which automatically tracks token usage at the gateway level, eliminating custom tracking pipelines. The system captures token statistics from each API request, applies usage-based pricing that differentiates between input and output tokens, and generates invoices that sync with Stripe for payment collection.