💡 _See its usage example [below 🔽](#multi-server-mode-with-custom-message-transfer)._
***`filter`** (_string_): this attribute assigns a custom topic filter to allow only specific Servers at the Clients-end in Multi-Server Mode only. Its usage is as follows:
***`filter`** (_string_): this attribute assigns a custom topic filter to allow only specific Servers at the Clients-end in Multi-Server Mode only. Its usage is as follows:
```python
```python
options={'multiserver_mode':True,'filter':'5565'}# activate Multi-Server Mode and set filter to allow data from topic `5565` only
options={'multiserver_mode':True,'filter':'5565'}# activate Multi-Server Mode and set filter to allow data from topic `5565` only
```
```
💡 _See its usage example [below 🔽](#multi-server-mode-with-custom-filter)._