adolf/extensions/telegram/AGENTS.md

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 10.1, July 1 2026.

Reliability Invariants

• Durable-before-ack on both transports. Polling: the ingress worker advances its offset only after the parent's committed spool enqueue. Webhook: respond 200 only after the spool write; a spool-write failure returning non-200 is the redelivery contract, not an error to fix.
• Completed spool rows tombstone via complete(), never delete. Telegram can refetch an update after dispatch, and callback side effects would rerun on a plain delete.
• One retry policy. spooled-update-retry-policy.ts is the sole owner of spool backoff and dead-letter decisions; the polling and webhook drains both consume it. The dead-letter age gate is a product decision: over-limit updates keep retrying at the capped delay and only tombstone once older than the minimum age. Do not dead-letter on raw attempt counts, and do not "unstick" a lane by removing the gate.
• Never swallow inbound processing errors. A transient store error on a spooled replay must record a failed-retryable processing result; a swallowed throw acks the update as completed and deletes the message.
• 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.