1# Callback and Command Patterns
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3Prefer small, typed handlers over large router files with implicit state.
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5## Callback queries
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7Recommended shape:
8- typed `CallbackData`
9- `@router.callback_query(MyCallback.filter(...))`
10- `await callback.answer(...)` for immediate user feedback
11- `edit_text(...)` or `edit_reply_markup(...)` when the callback updates the current screen
12- permission filters close to the router decorator
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14## Commands with reply-aware UX
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16For command handlers:
17- fail fast when args are missing and there is no meaningful reply
18- if used as a reply, explicitly merge reply context into the prompt or action
19- keep text parsing in helper functions rather than inside business logic
20- keep persistence DTO construction outside the handler body when possible
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22## Handler purity
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24Keep handlers thin:
25- parse Telegram input
26- call domain or service logic
27- render localized output
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29Move reusable Telegram parsing rules into helpers and DTO-producing functions.
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