Retrieve all recipients on a List

{
  "type": "object",
  "properties": {
    "recipients": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "recipients": {
            "type": "array",
            "items": {
              "type": "object",
              "required": [
                "email"
              ],
              "properties": {
                "created_at": {
                  "type": "number",
                  "description": "The time this record was created in your contactdb, in unixtime."
                },
                "custom_fields": {
                  "type": "array",
                  "description": "The custom fields assigned to this recipient and their values.",
                  "items": {
                    "type": "object"
                  }
                },
                "email": {
                  "type": "string",
                  "format": "email",
                  "description": "The email address of this recipient. This is a default custom field that SendGrid provides."
                },
                "first_name": {
                  "type": "string",
                  "description": "The first name of this recipient. This is a default custom field that SendGrid provides."
                },
                "id": {
                  "type": "string",
                  "description": "The ID of this recipient."
                },
                "last_clicked": {
                  "type": "number",
                  "description": "The last time this recipient clicked a link from one of your campaigns, in unixtime."
                },
                "last_emailed": {
                  "type": "number",
                  "description": "The last time this user was emailed by one of your campaigns, in unixtime."
                },
                "last_name": {
                  "type": "string",
                  "description": "The last name of the recipient."
                },
                "last_opened": {
                  "type": "number",
                  "description": "The last time this recipient opened an email from you, in unixtime."
                },
                "updated_at": {
                  "type": "number",
                  "description": "The last update date for this recipient's record."
                }
              }
            }
          }
        }
      }
    }
  }
}