----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Estimating Costs]() * [Billing Examples]() * [Pricing Overview]() * [Custom LLM]() -----------------------------

### Answer To address your question about the cost discrepancy, it's essential to consider that the total cost in Vapi may include additional components not immediately visible in your breakdown. Vapi charges for various elements such as the platform fee, transcription (STT), model inference (LLM), and text-to-speech (TTS), along with any telephony costs if applicable. Each of these elements could be contributing to the total cost you're seeing. The charges for these services can also vary based on the providers you're using, such as Openrouter for the LLM and any specific settings or configurations that might increase usage or complexity, thus affecting the cost. Unfortunately, without specific details on the call minutes or the exact configuration of your setup from the provided documents, I cannot give an exact breakdown or reason for the discrepancy you're observing. For a detailed understanding of how costs are estimated and broken down, you might want to refer to the Vapi documentation on estimating costs, which could provide some insights into how these calculations are made and why there might be differences in the expected vs. actual costs [(1)]() .

Yes I was using Openrouter with my API keys - is there an option to use it with Vapi's keys?

@Sahil @Jotham Following up