# grammY Integration (Telegram Bot API)

Updated: 2025-12-07

# Why grammY
- TS-first Bot API client with built-in long-poll + webhook runners, middleware, error handling, rate limiter.
- Cleaner media helpers than hand-rolling fetch + FormData; supports all Bot API methods.
- Extensible: proxy support via custom fetch, session middleware (optional), type-safe context.

# What we shipped
- **Single client path:** fetch-based implementation removed; grammY is now the sole Telegram client (send + relay) with the grammY throttler enabled by default.
- **Relay:** `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`.
- **Proxy:** optional `telegram.proxy` uses `undici.ProxyAgent` through grammY’s `client.baseFetch`.
- **Webhook helpers:** `webhook-set.ts` wraps `setWebhook/deleteWebhook`; `webhook.ts` hosts the callback with health + graceful shutdown and optional `--webhook-url` override.
- **Sessions:** direct chats map to `main`; groups map to `group:<chatId>`; replies route back to the same surface.
- **Config knobs:** `telegram.botToken`, `requireMention`, `allowFrom`, `mediaMaxMb`, `proxy`, `webhookSecret`, `webhookUrl`.
- **Tests:** grammy mocks cover DM + group mention gating and outbound send; more media/webhook fixtures still welcome.

Open questions
- Optional grammY plugins (throttler) if we hit Bot API 429s.
- Add more structured media tests (stickers, voice notes).
- Expose a `--public-url` flag in CLI for webhook registration convenience (currently `--webhook-url`).
