### Answer To see the user's phone number during a call, you can use the system default dynamic variable

{{user_number}}

[(1) ]() . This variable is automatically available for phone calls and represents the user's phone number (for inbound calls, it's the `from_number`; for outbound calls, it's the

to_number

) . You can reference

{{user_number}}

directly in your prompts, begin message, tool configurations, or other supported fields . For example, in your agent's prompt or greeting, you could use:

"Hello, I see you're calling from {{user_number}}. How can I help you today?"

The system provides several phone-specific default variables that are automatically available : - `{{user_number}}`: User's phone number - `{{agent_number}}`: Agent's phone number - `{{direction}}`: Call direction (inbound or outbound) - `{{call_id}}`: Current call session id These variables work without any configuration needed on your part . The spaces around the variable name will be trimmed when evaluating the variable . Regarding changes to dynamic variables, the changelog shows that Retell has been expanding dynamic variable capabilities, including adding more system default variables and features like default values for dynamic variables [(2) ]() . However, the core functionality of

{{user_number}}

remains a standard system variable [(1) ]() .

​ To learn more, see the sources I considered: [[1] Dynamic Variables](https://docs.retellai.com/build/dynamic-variables) [[2] Platform Changelogs | Retell AI](https://www.retellai.com/changelog) ​

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