​ To learn more, see the sources I considered: [[1] Deprecating on 03/31/2026](https://docs.retellai.com/deprecation-notice/2026/03-31_phone_number_agent_fields) [[2] List Phone Numbers](https://docs.retellai.com/api-references/list-phone-numbers) ​

### Answer To find where you're using the deprecated single-agent fields, you should check your phone number configurations for these specific deprecated fields [(1) ]() : Deprecated fields to look for: -

inbound_agent_id

,

inbound_agent_version

-

outbound_agent_id

,

outbound_agent_version

-

inbound_sms_agent_id

,

inbound_sms_agent_version

-

outbound_sms_agent_id

,

outbound_sms_agent_version

How to find them: Use the List Phone Numbers API to retrieve all your phone number configurations [(2) ]() :

javascript
import Retell from 'retell-sdk';
const client = new Retell({
 apiKey: 'YOUR_RETELL_API_KEY',
}) ;
const phoneNumberResponses = await client.phoneNumber.list() ;
console.log(phoneNumberResponses) ;

Check the response for any phone numbers that have the deprecated fields populated (non-null values) . Any phone number configuration using

inbound_agent_id

,

outbound_agent_id

,

inbound_sms_agent_id

, or

outbound_sms_agent_id

needs to be migrated [(1) ]() . Migration approach: Replace the deprecated single-agent fields with the new weighted agent lists : - Use

inbound_agents

instead of

inbound_agent_id

- Use

outbound_agents

instead of

outbound_agent_id

- Use

inbound_sms_agents

instead of

inbound_sms_agent_id

- Use

outbound_sms_agents

instead of

outbound_sms_agent_id

For a single agent, set the corresponding

*_agents

list to a single entry with

weight: 1

.

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

### Answer Got it—if you created all your phone numbers through the Retell dashboard GUI rather than programmatically, the deprecated fields were likely set automatically when you configured agents for those numbers in the UI [(1) ]() . To identify which phone numbers are using deprecated fields: Even though you didn't create them via API, you can still use the API to audit your existing phone number configurations. Use the List Phone Numbers endpoint [(2) ]() :

javascript
import Retell from 'retell-sdk';
const client = new Retell({
 apiKey: 'YOUR_RETELL_API_KEY',
}) ;
const phoneNumberResponses = await client.phoneNumber.list() ;
console.log(phoneNumberResponses) ;

What to look for in the response: Check if any phone numbers have these deprecated fields populated [(1) ]() : -

inbound_agent_id

and

inbound_agent_version

-

outbound_agent_id

and

outbound_agent_version

-

inbound_sms_agent_id

and

inbound_sms_agent_version

-

outbound_sms_agent_id

and

outbound_sms_agent_version

Migration note: The documentation states that "existing data is converted automatically and no action is required" and the APIs remain backwards-compatible until the deprecation date (03/31/2026) as long as only a single agent is used for each deprecated field . However, you'll need to update your phone number configurations to use the new weighted agent lists (

inbound_agents

,

outbound_agents

,

inbound_sms_agents

,

outbound_sms_agents

) before that date . You can make these updates either through the dashboard GUI or via the Update Phone Number API.

​ To learn more, see the sources I considered: [[1] Deprecating on 03/31/2026](https://docs.retellai.com/deprecation-notice/2026/03-31_phone_number_agent_fields) [[2] List Phone Numbers](https://docs.retellai.com/api-references/list-phone-numbers) ​

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 the specific steps to migrate from deprecated single-agent fields to weighted agent lists through the Retell dashboard GUI [(1) ]() . The documentation covers the API-based migration approach, where you would use the Update Phone Number API to replace deprecated fields like

inbound_agent_id

with the new

inbound_agents

weighted list format [(2) ]() [(1) ]() . For GUI-specific instructions, I'd recommend: - Check the phone number configuration section in your Retell dashboard for updated agent assignment options - Visit [Documentation]() - Visit [Hire certified Retell partner]() Would you like me to provide a general answer based on my knowledge instead?

​ To learn more, see the sources I considered: [[1] Deprecating on 03/31/2026](https://docs.retellai.com/deprecation-notice/2026/03-31_phone_number_agent_fields) [[2] Update Phone Number](https://docs.retellai.com/api-references/update-phone-number) ​

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