### Answer
Adding functions (tool calling) to your agent is included in Retell AI's base pricing—there's no separate charge for adding functions. [(1) ](
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Retell AI uses a pay-as-you-go model at $0.07+ per minute for AI Voice Agents, with features like CRM integrations and real-time processing included in that rate.
The per-minute cost can vary based on factors like which LLM your agent uses and whether you have a knowledge base attached—these choices affect your estimated cost per minute, which is displayed at the top of the screen when building your agent. [(2) ](
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For bulk discount inquiries, you can email support@retellai.com. [(3) ](
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