Summary

Fixes Slack outbound delivery-mirror session reconstruction for native Slack IM channel IDs (D...). A message.send call can legitimately target Slack’s concrete DM channel, but OpenClaw session routing should treat that same conversation as a direct Slack user session keyed by the peer U... user ID.

This PR updates the Slack outbound route resolver so D... and channel:D... targets resolve through Slack conversation metadata and only create a mirror route when Slack confirms channel.is_im plus channel.user. In that case the mirror session is canonicalized to slack:direct:<u...>, matching inbound Slack DM routing. If the lookup fails or Slack does not return the peer user, the mirror route is skipped instead of writing a known-wrong slack:channel:<d...> session key.

Fixes #80091.

Root Cause

Inbound Slack DM routing already treats D-prefixed Slack channels as IMs and keys the route by the message sender user ID. The outbound delivery-mirror path did not do the same. It parsed bare outbound targets with defaultKind: "channel", only reclassified G... IDs, and therefore allowed a Slack IM channel ID such as D0AEWSDHAQH to produce a session key like:

agent:main:slack:channel:d0aewsdhaqh:thread:1778110574.653649

Later inbound messages in the same visible Slack DM thread route to the canonical direct user session, for example:

agent:main:slack:direct:u09g2dj0275:thread:1778110574.653649

That split loses prior thread context even though the Slack UI shows one DM thread.

What Changed

• Added Slack conversation metadata lookup that can return both conversation type and the IM peer user.
• Kept the existing resolveSlackChannelType() contract as a compatibility wrapper.
• Canonicalized outbound mirror routes for bare D... and channel:D... targets to direct:U... when Slack confirms the mapping.
• Preserved Slack send delivery behavior. channel:D... can still be used as the concrete Slack delivery target; only mirror/session reconstruction changes.
• Preserved existing channel and MPIM behavior for C... and G... targets.
• Avoided caching incomplete native IM metadata so transient Slack lookup failures do not suppress later successful mirror routing.
• Added regression coverage for the affected paths.

User Impact

After this change, sending into a Slack DM thread through message.send with a native D... target no longer creates a separate channel-scoped OpenClaw session. Outbound delivery mirrors and later inbound DM turns resolve to the same direct user session whenever Slack exposes the peer user mapping.

Existing bad agent:*:slack:channel:d... sessions are not migrated in this PR. This PR prevents new bad mirror sessions from being created.

Real Behavior Proof

Pending live after-fix proof from a real Slack-connected OpenClaw setup.

Planned proof:

1. Use a real Slack IM channel ID (D...) and real thread timestamp from a Slack DM where OpenClaw is configured.
2. Confirm live Slack metadata resolves the IM channel to the peer user:

conversations.info(channel=D...)
  channel.is_im: true
  channel.user: U...

3. Run the same outbound mirror route probe before and after this fix.
4. Record copied terminal output showing the route changes from the pre-fix channel session:

agent:main:slack:channel:<d...>:thread:<thread_ts>

to the post-fix direct user session:

agent:main:slack:direct:<u...>:thread:<thread_ts>

Unit tests, typechecks, and CI below are supplemental only and do not replace this live proof.

Validation

• git diff --check
• pnpm test extensions/slack/src/channel.test.ts extensions/slack/src/channel-type.test.ts
• pnpm test:extension slack
• pnpm tsgo:extensions
• pnpm exec oxfmt --check --threads=1 extensions/slack/src/channel.ts extensions/slack/src/channel-type.ts extensions/slack/src/channel.test.ts extensions/slack/src/channel-type.test.ts CHANGELOG.md
• codex review --base origin/main

codex review result: no discrete correctness issues found.

AI Assistance

Implemented with Codex. I understand the submitted change and verified the behavior at the code and targeted validation level; live real-behavior proof is pending as noted above.