### Answer I don't have information in the available sources about rate limiting or message volume controls specifically for two-way SMS chat agents. The documentation covers how to enable SMS capabilities [(1) ]() , set up two-way SMS conversations by attaching chat agents to numbers , and create outbound SMS via API [(2) ]() , but doesn't mention built-in features to limit the number of messages sent. If you need help with this, check out these potentially useful sources: - [Send & receive SMS]() - [Create Outbound SMS]() Would you like me to provide general guidance on potential approaches to implement rate limiting?

​ To learn more, see the sources I considered: [[1] Send & receive SMS](https://docs.retellai.com/deploy/enable-sms) [[2] Create Outbound SMS](https://docs.retellai.com/api-references/create-sms-chat) ​

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

### Answer I don't have specific information about built-in SMS rate limiting features for two-way chat agents in the available Retell AI documentation. However, I can suggest some general approaches you might consider: Application-Level Rate Limiting: - Implement rate limiting in your own backend before calling the Create Outbound SMS API [(1) ]() - Track message counts per user/phone number using your own database - Set thresholds (e.g., max messages per hour/day) and reject requests that exceed limits IP-Based Protection: - While Retell offers fraud protection that rate limits based on IP address and destination phone number for public key requests [(2) ]() , this applies to outbound phone calls and SMS initiated via public key authentication Webhook-Based Control: - Use inbound webhooks to filter and add context to inbound SMS [(1) ]() - Implement logic in your webhook handler to track conversation volume and stop responding after certain thresholds Geographic Restrictions: - Configure allowed inbound and outbound countries to limit where SMS can be sent [(2) ]() For the most reliable approach, I'd recommend implementing rate limiting at your application layer where you have full control over the logic and thresholds that match your specific use case.

​ To learn more, see the sources I considered: [[1] Send & receive SMS](https://docs.retellai.com/deploy/enable-sms) [[2] Fraud Protection](https://docs.retellai.com/reliability/fraud-protection) ​

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

### Answer I don't have information in the available sources about SMS pricing or whether you're charged for incoming user messages versus outgoing agent messages. The documentation covers how to enable SMS capabilities [(1) ]() , create outbound SMS [(2) ]() , and set up two-way conversations [(1) ]() , but doesn't include details about the billing model for SMS messages. For pricing information specific to SMS usage, check out these potentially useful sources: - [Send & receive SMS]() - [Create Outbound SMS]() You may want to reach out to Retell AI support directly or check your billing dashboard for detailed pricing information about SMS message costs.

​ To learn more, see the sources I considered: [[1] Send & receive SMS](https://docs.retellai.com/deploy/enable-sms) [[2] Create Outbound SMS](https://docs.retellai.com/api-references/create-sms-chat) ​

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