curl --request GET \
  --url https://api.sentvia.ai/v1/threads \
  --header 'Authorization: Bearer <token>'

{
  "threads": [
    {
      "id": "<string>",
      "subject": "<string>",
      "last_message_at": "<string>",
      "messages": [
        {
          "id": "<string>",
          "thread_id": "<string>",
          "direction": "<string>",
          "from_addr": "<string>",
          "to_addrs": [
            "<string>"
          ],
          "subject": "<string>",
          "body_text": "<string>",
          "delivery_status": "<string>"
        }
      ]
    }
  ]
}