- **Single client path:** fetch-based implementation removed; grammY is now the sole Telegram client (send + gateway) with the grammY throttler enabled by default.
- **Gateway:** `monitorTelegramProvider` builds a grammY `Bot`, wires mention/allowlist gating, media download via `getFile`/`download`, and delivers replies with `sendMessage/sendPhoto/sendVideo/sendAudio/sendDocument`. Supports long-poll or webhook via `webhookCallback`.
- **Webhook support:** `webhook-set.ts` wraps `setWebhook/deleteWebhook`; `webhook.ts` hosts the callback with health + graceful shutdown. Gateway enables webhook mode when `channels.telegram.webhookUrl` + `channels.telegram.webhookSecret` are set (otherwise it long-polls).
- **Sessions:** direct chats collapse into the agent main session (`agent:<agentId>:<mainKey>`); groups use `agent:<agentId>:telegram:group:<chatId>`; replies route back to the same channel.
- **Live stream preview:** `channels.telegram.streaming` (`off | partial | block | progress`) sends a temporary message and updates it with `editMessageText`. This is separate from channel block streaming.