For the WebChat feature, you are correct in noting that it bypasses traditional TTS (Text-to-Speech) and STT (Speech-to-Text) costs since it is text-based. For the Agency tier, the LLM and transport costs appear as being included in the $0.05 per minute pricing. This is indeed different from the call costs where additional fees for STT, TTS, and telephony might apply.
For Agency accounts using WebChat, expect simplified billing largely centered on the $0.05 per minute charge for the text-based interaction. More details on chat testing and configurations can be found in the [Chat Testing documentation](
https://docs.vapi.ai/test/chat-testing).