# Telegram Plugin Guide Read this before any change under `extensions/telegram/`. These are intentional maintainer decisions and review-binding invariants, not incidental implementation details. Also read `extensions/AGENTS.md` for the plugin boundary rules. Verified against Telegram Bot API 10.2, July 14 2026. ## Reliability Invariants ### Core drain contracts (do not re-implement in Telegram) Owned by `src/channels/message/ingress-drain.ts` (+ claim-owner, retry-policy). Proof: `src/channels/message/ingress-drain.test.ts`, `ingress-claim-owner.test.ts`, `ingress-retry-policy.test.ts`. - Completed rows tombstone via `complete()`, never `delete`. - Complete at turn adoption, not settle. Deferred holds the claim; watchdog stays armed through deferral; dead-letter reason `handler-timeout`. - One retry policy: attempt floor **and** age gate (defaults 8 / 24h). - Claim refresh heartbeat while dispatching/deferred (`claimLeaseMs / 3`). - Never silently complete on transient failure — release/fail via disposition. - Pre-adoption supersede tombstones; post-adoption interruption is core-owned (reply-run registry / queue interrupt). ### Telegram-owned (transport + channel policy) - Durable-before-ack on both transports. Polling: ingress worker advances its offset only after the parent's committed spool enqueue (`writeTelegramSpooledUpdate`). Webhook: respond 200 only after the spool write; non-200 on write failure is the redelivery contract. - `update_id`↔event-id encoding and per-chat/topic lane derivation stay in `telegram-ingress-spool.ts` / sequential-key. - Polling and webhook both: enqueue then pump `createTelegramTransportIngressDrain(...).drainOnce()` — no private claim loops. - Stall timeout: `OPENCLAW_TELEGRAM_SPOOLED_HANDLER_TIMEOUT_MS` → `adoptionStallTimeoutMs` (default 5 min) via `resolveTelegramAdoptionStallTimeoutMs`. - Non-retryable classifier: `telegram-ingress-non-retryable.ts` (missing harness, dispatch-dedupe rollback). - Supersede predicate: `telegram-ingress-supersede.ts` — only abort text / authorized-looking explicit commands (and ambient room_event pending) may supersede pre-adoption work. Normal messages never supersede. - room_event ambient work shares the sequential lane so a later user turn can supersede it pre-adoption; adopted user turns are never touched (core drain supersede is pre-adoption only). - No per-message full-store writes. Hot-path SQLite writes are per-entry. Rewriting a cache on every send or read stalls the event loop, and that stall masquerades as a polling stall (the sent-message-cache regression). - Transport error classification. The getUpdates worker retries Bot API 5xx and 429 locally, honoring `parameters.retry_after`; 401/404 stay fatal; 409 must propagate to the parent session, which owns webhook-conflict recovery. Bot API errors carry `error_code`, not `.code`; parse non-2xx bodies defensively (a 502 HTML page is not JSON). - Send funnel parity. The durable funnel (`send.ts`) and the streaming funnel (`bot/delivery.*`) must degrade identically: rich-entity 400 falls back to plain text, caption parse 400 falls back to a plain caption, quote-not-found 400 falls back to a legacy reply. New recoveries go into the shared predicates (`send-error-predicates.ts`, `reply-parameters.ts`), never into one funnel only. - Outbound flood waits honor `retry_after` up to `TELEGRAM_OUTBOUND_RETRY_AFTER_CAP_MS`; do not re-clamp Telegram sends to the generic channel retry ceiling. - Webhook security ordering. The secret header is validated first (constant-time compare, single-header enforcement, connection close on 401); the request rate limit budgets only failed-auth attempts so Telegram's own delivery is never throttled. - Every owned undici transport gets closed on all exit paths: polling session, webhook shutdown and startup failure, probe-cache eviction. ## Streaming - Do not reintroduce `sendMessageDraft` for answer streaming. Telegram drafts are ephemeral 30-second previews in private chats; final delivery still requires a separate `sendMessage`. OpenClaw uses `sendMessage` plus `editMessageText`, then finalizes in place so the user sees one persistent answer. - Streaming owns one visible preview message. Edit it forward. Do not send an extra final bubble unless the final edit genuinely failed. - Keep the first-preview debounce. If a provider sends token-sized deltas, coalesce them into cumulative preview text instead of removing the debounce. - Respect Telegram limits in the Telegram layer. Text over 4096 chars chains into continuation messages. Polls keep the current Bot API 12-option cap. ## Telegram API Ownership - Prefer grammY primitives and Telegram-native helpers when they model the behavior directly. Avoid custom Bot API wrappers for behavior grammY already owns. - Throttling is bot-token scoped. All Telegram API clients for the same token share one grammY `apiThrottler()` instance. - Do not silently retry failed topic sends without topic metadata. A wrong-surface success is worse than a loud Telegram error. - DM topics and forum topics are distinct. `direct_messages_topic_id` and `message_thread_id` are not interchangeable. ## Context And Authorization - Reply context comes from OpenClaw-observed messages. Bot API updates expose `reply_to_message`, but there is no arbitrary `getMessage(chat, id)` hydration path later. - Current local chat context must outrank stale reply ancestry in the prompt. Old replied-to messages should not look like the active conversation. - The group history window is always on for groups and bounded by `historyLimit`. Do not reintroduce prompt-history gating modes; that regression blinded ambient rooms. - The group history window is rolling. Use self-entry watermark selection for "since your last reply" views; do not reintroduce destructive clears because room events are not persisted to the session and cleared context is unrecoverable. - Pairing is DM-only. Group and topic authorization need explicit config allowlists. - Telegram allowlists use numeric sender IDs. Usernames are optional, mutable, and not a reliable arbitrary-user lookup key in the Bot API. - Group and channel visible replies are policy-controlled. Normal room replies stay private unless `messages.groupChat.visibleReplies: "automatic"` is set or the agent explicitly calls `message.send`. ## Interactive Surfaces - Native callbacks stay structured. Approval, native command, plugin, select, and multiselect callbacks must not fall through as raw callback text. - Preserve callback values exactly, including delimiters such as `env|prod`. - Native slash commands should remain fast-pathable before full workspace and agent-turn setup. ## Review Standard - Telegram behavior PRs need real Telegram proof when they touch transport, streaming, topics, callbacks, authorization, or reply context. Prefer the bot-to-bot QA lane or an equivalent live Telegram probe over synthetic-only validation. - Reliability PRs (spool, drain, retry, ack, offset paths) need crash-window or restart-replay test proof, not just happy-path tests.