----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Introduction]() * [Web Calling]() * [Creating Custom Knowledge Bases for Your Voice AI Assistants]() * [Introduction]() -----------------------------

### Answer To effectively monitor the usage and billing of voice AI assistants provided to multiple businesses using Vapi, you can utilize the detailed billing examples provided in Vapi's documentation. These examples show how to estimate costs based on different voice pipeline configurations and usage scenarios, which can help you manage and monitor the usage for each agent or business. You can create a custom system to track usage and billing by associating each assistant with a specific client and maintaining records of their usage and corresponding costs. This could involve tracking the number of calls, duration, and specific features used, and then calculating the costs based on the pricing models provided by Vapi. For detailed instructions on how to estimate costs and track usage, you can refer to the Billing Examples section in the Vapi documentation [(1)]() .