### Answer The $8 charge for Knowledge Base Hosting is for an additional knowledge base beyond the free allocation. [(1) ]() Here's how the pricing works: - Every workspace includes 10 free knowledge bases - Additional knowledge bases beyond those 10 are charged at $8/month each, billed at the end of the month This means you likely have more than 10 knowledge bases in your workspace, and the $8 covers hosting for the 11th one. Additionally, there's a separate usage cost of $0.005 per minute when the knowledge base is actively used during calls.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Knowledge base, Verified phone number, Realtime API and more](https://www.retellai.com/changelog/knowledge-base-verified-phone-number-realtime-api-and-more) ​

@AI Evy does the amount change when you add more knowledge bases or not?

### Answer Yes, the amount increases as you add more knowledge bases beyond the free allocation. [(1) ]() - Every workspace includes 10 free knowledge bases - Each additional knowledge base beyond those 10 is charged at $8/month So if you have 12 knowledge bases, you'd pay $16/month (2 × $8) for the extra two. The charge scales linearly with each additional knowledge base you add.

​ To learn more, see the sources I considered: [[1] Knowledge base, Verified phone number, Realtime API and more](https://www.retellai.com/changelog/knowledge-base-verified-phone-number-realtime-api-and-more) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer ### Answer With 20 knowledge bases, you'd pay $80/month for the hosting portion. [(1) ]() Here's the breakdown: - 10 knowledge bases are included free per workspace - 10 additional knowledge bases (20 - 10 = 10) × $8/month = $80/month Keep in mind there's also a separate usage cost of $0.005 per minute when the knowledge base is actively used during calls—this is billed based on actual usage, not a flat fee.

​ To learn more, see the sources I considered: [[1] Knowledge base, Verified phone number, Realtime API and more](https://www.retellai.com/changelog/knowledge-base-verified-phone-number-realtime-api-and-more) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer ### Answer Based on the pricing documentation, here are the key costs that scale as you add more agents/clients: [(1) ]() Monthly Subscription Items: - **Phone Numbers**: $2.00/month per Retell phone number - **Concurrency (Active Calls) **: $8.00/concurrency/month (first 20 concurrent calls are free) - **Knowledge Base**: $8.00/month each (first 10 are free) - **Verified Phone Number**: $100.00/month per verified number - **Retell SMS**: $20.00/month Usage-Based Add-ons: - **Knowledge Base usage**: +$0.005/minute when actively used - **Batch Call**: +$0.005/dial - **Branded Call**: +$0.10/outbound call - **Advanced Denoising**: +$0.005/min - **PII Removal**: +$0.01/min - **SMS**: $0.01/msg The core per-minute costs (LLM + Voice Engine + Telephony) remain the same regardless of how many agents you have—you just pay for actual usage.

​ To learn more, see the sources I considered: [[1] AI Phone Agent Pricing | Retell AI](https://www.retellai.com/pricing) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.