# Type Alias: ChatId

> **ChatId**: [`ContactId`](/reference/api/model/aliases/type-aliases/ContactId.md) \| [`GroupChatId`](/reference/api/model/aliases/type-aliases/GroupChatId.md)

A chat id ends with `@c.us` or `@g.us` for group chats.

Example:

A group chat: `"447123456789-1445627445@g.us"`
A group chat: `"447123456789@g.us"`
