Summary

@openclaw/slack does not emit the documented message_sent plugin hook
after a successful outbound Slack delivery, even though the hook is
contracted as observation-only for all outbound paths
(docs/plugins/hooks.md).

A plugin that registers api.on("message_sent", …) receives notifications
for outbound Telegram messages (Telegram fires runMessageSent directly in
extensions/telegram/src/bot/delivery.replies.ts) but never for Slack.

Versions

• openclaw 2026.5.28
• @openclaw/slack 2026.5.28
• Reproduced on a clean local install (macOS, Node 25) with no patches.

Steps to reproduce (real behavior, no mocks)

1. Install stock [email protected] + @openclaw/[email protected].
2. Register a plugin that listens on the full Slack outbound hook chain:

api.on("message_received",      ev => log.info("📬 message_received"));
api.on("before_dispatch",       ev => log.info("➡️  before_dispatch"));
api.on("agent_end",             ev => log.info("🏁 agent_end"));
api.on("reply_payload_sending", ev => log.info("📦 reply_payload_sending"));
api.on("message_sending",       ev => log.info("📤 message_sending"));
api.on("message_sent",          ev => log.info("✅ message_sent  ← never fires"));

Configure the plugin with plugins.entries.<id>.hooks.allowConversationAccess = true.

3. @mention the bot in a Slack channel where it's a member.
4. Watch the gateway log.

Observed

[plugin] 📬 message_received fired channelId=slack
[plugin] ➡️  before_dispatch fired channelId=slack
[plugin] 🏁 agent_end fired
[plugin] 📦 reply_payload_sending fired channelId=slack
[plugin] 📤 message_sending fired channelId=slack content_preview="Yep, still here…"
                                                            ← message delivers to Slack here
                                                            ← message_sent NEVER fires

The Slack message lands in the channel successfully; only message_sent is silently missing.

Root cause (analysis on latest main)

grep -rln "runMessageSent\b" --include="*.ts" src/ extensions/

returns:

• src/infra/outbound/deliver.ts — the deprecated deliverOutboundPayloads
• extensions/telegram/src/bot/delivery.replies.ts — Telegram fires it directly
• (test / mock files)

extensions/slack/ has zero references. The new sendDurableMessageBatch path
(src/channels/message/send.ts) — which the migrated Slack adapter routes through —
also does not call runMessageSent. Telegram works only because it has its own
adapter-side emit; Slack was migrated to the unified pipeline in 05eda57b3c
("refactor: migrate bundled plugins to message lifecycle") without adding the
equivalent message_sent emission.

Impact

Any plugin attempting to observe message delivery to build something on top
(per-message metrics, post-delivery UI overlays, analytics extractors, audit
logs) currently gets a complete blind spot for Slack while Telegram works
out of the box.

Proposed fix

Mirror Telegram's pattern in the Slack adapter: add an
emitSlackMessageSentHooks helper that fires both the plugin hook and the
internal hook, and call it from sendSlackOutboundMessage after each
successful (and failed) chat.postMessage.

PR with the fix attached.