curl --request GET \
  --url https://api.retellai.com/v2/list-phone-numbers \
  --header 'Authorization: Bearer <token>'

{
  "pagination_key": "<string>",
  "has_more": true,
  "items": [
    {
      "phone_number": "+14157774444",
      "phone_number_type": "retell-twilio",
      "last_modification_timestamp": 1703413636133,
      "phone_number_pretty": "+1 (415) 777-4444",
      "allowed_inbound_country_list": [
        "US",
        "CA",
        "GB"
      ],
      "allowed_outbound_country_list": [
        "US",
        "CA"
      ],
      "area_code": 415,
      "inbound_agents": [
        {
          "agent_id": "oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD",
          "weight": 0.5,
          "agent_version": 1
        }
      ],
      "outbound_agents": [
        {
          "agent_id": "oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD",
          "weight": 0.5,
          "agent_version": 1
        }
      ],
      "inbound_sms_agents": [
        {
          "agent_id": "oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD",
          "weight": 0.5,
          "agent_version": 1
        }
      ],
      "outbound_sms_agents": [
        {
          "agent_id": "oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD",
          "weight": 0.5,
          "agent_version": 1
        }
      ],
      "nickname": "Frontdesk Number",
      "inbound_webhook_url": "https://example.com/inbound-webhook",
      "inbound_sms_webhook_url": "https://example.com/inbound-sms-webhook",
      "sip_outbound_trunk_config": {
        "termination_uri": "someuri.pstn.twilio.com",
        "auth_username": "username",
        "transport": "TCP"
      },
      "fallback_number": "+14155551234"
    }
  ]
}