Telegram threads and sessions

Forum supergroups: topic session keys append :topic:<threadId>; replies and typing target the topic thread; topic config path is channels.telegram.groups.<chatId>.topics.<threadId>.

General topic (threadId=1) is a special case: message sends omit message_thread_id (Telegram rejects sendMessage(...thread_id=1) with "thread not found"), but typing actions still include message_thread_id (empirically required for the typing indicator to appear).

Topic entries inherit group settings unless overridden (requireMention, allowFrom, skills, systemPrompt, enabled, groupPolicy). agentId is topic-only and does not inherit from group defaults. topics."*" sets defaults for every topic in that group; exact topic IDs still win over "*".

Per-topic agent routing: each topic can route to a different agent via agentId in the topic config, giving it its own workspace, memory, and session:

{  channels: {    telegram: {      groups: {        "-1001234567890": {          topics: {            "1": { agentId: "main" },      // General topic -> main agent            "3": { agentId: "zu" },        // Dev topic -> zu agent            "5": { agentId: "coder" }      // Code review -> coder agent          }        }      }    }  }}

Each topic then has its own session key, for example agent:zu:telegram:group:-1001234567890:topic:3.

Persistent ACP topic binding: forum topics can pin ACP harness sessions through top-level typed bindings (bindings[] with type: "acp", match.channel: "telegram", peer.kind: "group", and a topic-qualified id like -1001234567890:topic:42). Currently scoped to forum topics in groups/supergroups. See ACP Agents.

Thread-bound ACP spawn from chat: /acp spawn <agent> --thread here|auto binds the current topic to a new ACP session; follow-ups route there directly, and OpenClaw pins the spawn confirmation in-topic. Controlled by session.threadBindings.spawnSessions (default: true).

Template context exposes MessageThreadId and IsForum. DM chats with message_thread_id keep reply metadata but only use thread-aware session keys when Telegram getMe reports has_topics_enabled: true. The retired dm.threadReplies and direct.*.threadReplies overrides are gone; BotFather threaded mode is the single source of truth. Run openclaw doctor --fix to remove stale config keys.