# Схема: ButtonCallback

Source: <https://telegafirst.com/docs/schema-4fff85570d7119a3227c715880cd0f4b2179370507d0b324a126ca523588aa44>
Locale: ru
releaseGitSha: a14c924a094abb9d1fe9c04b453df6efc599f887
sourceContentDigest: 6f3374896e96c3d5dfc2bc6a5adf31f88019fc183af966ac926da0f287f1a0bf
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 by the button.clicked webhook to the server of the app that sent the push, so the app must have been subscribed to the button.clicked webhook when it was provisioned, otherwise the button is refused with INVALID\_BUTTON\_CONFIG. 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" |