# Схема: ButtonCallback

Source: <https://telegafirst.com/docs/schema-15a8700247814ce812208a86bbaf212736e365b6548a7e08d6b7fdd697a4da8b>
Locale: ru
releaseGitSha: ea133cd4ad87fe549ef000b139be145be9bd1717
sourceContentDigest: 2bc099e406bf5c114af9d0c519496ee2af7440a2a722d7579b51dd83a6978a7f
Version: 1

# Схема: ButtonCallback

| Поле | Значение |
| - | - |
| properties.callback\_data.description | "An integration mechanism of an ExternalApp key: when the user taps the button, the value is delivered to your server by the button.clicked webhook. Sent with any other credential (an OAuth grant or an M2M credential) a callback button is refused with INVALID\_BUTTON\_CONFIG; the MCP send\_notification tool carries url buttons only. The platform prefixes it with ext:{app}:, and the prefixed value must fit 64 bytes. Answered only for a Telegram user: for a MAX or VK user a callback button is refused with INVALID\_BUTTON\_CONFIG — use a url button." |
| properties.callback\_data.maxLength | 64 |
| properties.callback\_data.type | "string" |
| properties.text.maxLength | 30 |
| properties.text.type | "string" |
| properties.type.enum | \["callback"] |
| properties.type.type | "string" |
| required | \["text","type","callback\_data"] |
| type | "object" |