# Filters for incoming updates

Filters are used to subscribe to the update receive event.

Filter is an object of the following structure:

```javascript
{
    type: <regexp for type>,
    contents: <regexp for contents>,
    params: <regexp for params>,
    chat: <regexp for chat_id>,
    chat_type: <regexp for chat_type>,
    user: <regexp for user_id>
}
```

where:

- *\<regexp for type\>* - expression for matching type of message
- *\<regexp for contents\>* - expression for matching type of message
- *\<regexp for params\>* - expression for matching in params substring in messages with bot commands, optional
- *\<regexp for chat_id\>* - may be ID of particular chat or *private* for updates wich sent to the bot directly, optional. If not specified, will receive updates of any chat
- *\<regexp for chat_type\>* - expression for matching type of chat (one of values: 'private', 'group', 'supergroup')
- *\<regexp for user_id\>* - ID of user whom was send this message