# Callback Contract

## Goal

Define a stable callback payload contract between channel-specific button handlers and the reusable reply-end-controls core.

## Telegram V1 callback values

- `rec:continue`
- `rec:stop`

## Optional message-scoped extension

If V1 needs tighter message binding later, extend to:

- `rec:continue:<messageId>`
- `rec:stop:<messageId>`

## Normalized internal event

Suggested normalized structure after channel parsing:

```json
{
  "choice": "continue | stop",
  "conversationId": "string",
  "sessionKey": "string | null",
  "sourceMessageId": "string",
  "sourceCallbackId": "string",
  "channel": "telegram",
  "timestamp": "ISO timestamp"
}
```

## Why normalize

The Telegram parser should convert platform-specific callback payloads into one internal structure, so the reusable policy/state layer does not need to know Telegram details.