slack replyToMode:all still process the first msg in channel's main session

[alpine rock]

Description:
I am trying to implement a document review workflow where the user uploads a file and @mentions the agent in a Slack channel. I want the agent to process the file and send the initial review into a thread, with all subsequent discussions staying within that thread-scoped session.
Expected Behavior:
The entire interaction (from the first @mention + file upload to the final reply) should ideally be handled within or immediately transitioned to a thread-scoped session (... thread:ts) so that tool execution states and thinking traces are preserved for follow-up questions in the thread.

Actual Behavior & Findings:

1. Context Split: When the 1st message arrives in the channel, OpenClaw processes it in the Channel's main session.
2. Tool Execution: The doc-review tool call and thinking process occur in the main session.
3. Thread Limbo: Although the reply is sent to a thread (via message.send(threadId=x) due to replyToMode: all), no actual thread scoped session is created in the backend yet.
4. Amnesia: When the user replies @agent inside the new thread, OpenClaw initializes a new thread-scoped session. This session has no record of the previous tool calls or thinking traces from the main session, causing the agent to "re-process" or lose track of how the first reply was generated.

Relevant GitHub Issues found:

• Likely related to #4470 (Populate Slack thread sessions with existing history) or general session inheritance logic.

My Setup:

• OpenClaw Version: 2026.4.14 (323493f)
• Hosting: MacOS 13.7.8
• Providers: Minimax

Relevant Config (openclaw.json):

"slack": {
  "enabled": true,
  "mode": "socket",
  "channels": {
    "YOUR_CHANNEL_ID": {
      "enabled": true,
      "requireMention": true
    }
  },
  "thread": {
    "requireExplicitMention": true
  },
  "replyToModeByChatType": {
    "channel": "all"
  }
}

---

• Is this known issue?
• Are there any configs that I can try?
• Does later openclaw version has some fixes?

[mental fable]

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[night birch]

Let me verify against the actual docs/source so I don't guess.

I'm digging into the actual Slack thread routing code now, because the docs alone don't answer the "does the first channel mention inherit into the new thread session?" part.

Yep, this gap is real.

Short version:

• replyToModeByChatType.channel: "all" affects where the reply is sent, not which session the first inbound turn runs on.
• For Slack channel messages, OpenClaw currently keeps the first top-level mention on the channel session.
• The :thread:<ts> session only starts on a real threaded inbound reply.

So what you saw is consistent with current behavior, not just a bad config.

What to try today:

{
  channels: {
    slack: {

      enabled: true,
      mode: "socket",
      replyToModeByChatType: {
        channel: "all"
      },
      thread: {
        requireExplicitMention: true,
        inheritParent: true,
        initialHistoryLimit: 50
      }
    }
  },
  session: {
    parentForkMaxTokens: 200000
  }

}

What those do:

• thread.inheritParent: true is the important one. It makes the first real thread session fork from the parent channel session, so follow-up thread replies should inherit prior transcript/history instead of feeling blank.
• thread.initialHistoryLimit only pulls Slack thread messages as extra context. It does not copy the parent channel session by itself.
• thread.requireExplicitMention only changes mention gating inside threads.
• session.parentForkMaxTokens matters if the parent session is large, otherwise the fork can be skipped.

If you enable inheritParent, check logs with:

openclaw logs --follow

You want to see something like:

• forking from parent session
• not skipping parent fork (parent too large)

About newer versions:

• There are newer Slack thread-context fixes/polish on main.
• I do not see a fix that changes this core behavior so the initial channel mention executes directly inside the future thread session.

So, upgrade is still reasonable, but I would not expect it to solve this exact split by itself.

My recommendation:

1. Turn on thread.inheritParent: true
2. Raise parentForkMaxTokens if needed
3. If you need true “first turn already lives in thread session” behavior, file/track a GitHub issue, because that likely needs a code change, not a config tweak: https://github.com/openclaw/openclaw/issues

Docs:

• Slack: https://docs.openclaw.ai/channels/slack
• Config reference: https://docs.openclaw.ai/gateway/configuration-reference

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[alpine rock]

i would like to know more about the behavior of inheritParent

in my use case, when the agent do the "review" skill, all those tool calls / thinking state will "pollute" the main session, and finally reply the result in the newly created thread due to replyToMode: all

if i turn on inheritParent and later i @agent inside the new thread
will this include those thinking / tool calls state?
or just messages?

i dont need messages from channel
i only want those thinking / tool calls state can be synced in the thread

[night birch]

Let me check one detail in the session code so I don’t overstate what inheritParent copies.

Yeah, inheritParent is closer to a full transcript fork, not a “sync only tool state” feature.

So for your exact question:

• Not just messages.
• It can bring over the persisted parent session transcript, which can include:
  • user/assistant messages
  • persisted tool call / tool result entries
  • persisted assistant commentary blocks, if they were written to the transcript

But:

• it does not recreate live in-memory state
• it does not copy hidden/private model chain-of-thought that was never persisted
• it does not selectively copy “tool/thinking only” while excluding normal channel transcript

So in your workflow:

1. first @agent + file in channel runs on the channel main session
2. review skill + tool calls land in that main session transcript
3. later, when you @agent inside the Slack thread, if thread.inheritParent: true is on,
   the new :thread:<ts> session is forked from that parent channel session

That means the thread session should inherit the persisted review run context, but it will inherit it as part of the whole parent transcript, not as an isolated “tool state only” package.

So the bad news is:

• if the main channel session already has unrelated stuff, that comes along too
• inheritParent is a partial mitigation, not a clean fix for your use case

The most accurate mental model is:

• inheritParent = branch the parent session file
• not inheritParent = sync only the last tool execution state

For your goal, “I want only the review run state, not channel chat pollution”, there is no config today that does that cleanly.

So my honest recommendation is:

• If the channel main session is otherwise pretty empty, inheritParent: true is worth trying.
• If you need strict isolation, where the very first review turn already belongs to the future thread session, this needs a product/code change, not just config.

If helpful, I can also sketch what the ideal behavior change would look like in OpenClaw terms, so you can file a very precise GitHub issue.

[alpine rock]

how about can i use some prompt in AGENTS.md
to let agent to "create" the thread session, and trigger the "review skill" inside the new thread session instead of main session ?

[night birch]

I want to check one thing before I say “no”, specifically whether Slack has any thread-binding path you could piggyback on.

Short answer, no, not with AGENTS.md alone.

Why:

• Session routing happens before the agent prompt is even built.
• By the time AGENTS.md is read, OpenClaw has already decided:
  • this is the channel main session
  • not a Slack :thread:<ts> session

So a prompt cannot retroactively say “actually run this first turn in a new thread session instead”.

Also, for Slack specifically, there is not a first-class “thread-bound session spawn/bind” path like Discord has. Current docs only call out persistent thread-bound subagent sessions for Discord in the subagent flow.

So the best AGENTS.md can do is something like:

• first turn in main session
• tell the agent to create/reply in a thread

• ask the user to continue there
• maybe defer the heavy review until the user replies in thread

But that still means:

• the first turn already touched the main session
• and the real review would only happen on the second turn

So for your exact goal, “create thread session first, then run review inside it”, you need a routing/plugin change, not a prompt trick.

The two real solutions are:

1. Core Slack adapter change
   Treat the initial top-level mention + replyToMode: all as a thread-root session before execution.

2. Custom pre-agent hook / workflow
   Intercept the Slack event before agent execution, create the thread, then reinject the request against the thread-scoped session.

If you want, I can help you write the exact GitHub issue wording for that feature, or sketch the implementation points in the Slack adapter so it’s easier to discuss with maintainers.

[alpine rock]

i suddenly have a thought, please check if it is viable:

• in agents.md i will add a rule that, when agent detects it is in "channel's main session" and user want it to review something
• DO NOT start review immediately, instead reply in that thread with "@agent itself i will now start review", then stop any further actions
• only continue to review if it detects current context is "in a slack thread"
• now if this @agent mention works, this will be treated as a "thread inbound msg" => create a thread scoped session based on this newly created thread context, and trigger a run turn on this agent
• so everything will be running in this thread context

[night birch]

Let me sanity-check one part, whether Slack inbound would even wake on the bot’s own @agent message.

Nice idea, but not viable in the self-mention form.

The part that breaks is this:

• OpenClaw/Slack ignores the bot’s own inbound messages
• so a bot message like @agent I will now start review will not wake a second run
• even with bot handling enabled, the Slack inbound path explicitly drops messages from the same bot user

So this version:

• bot replies in thread
• bot mentions itself
• bot expects that to create a new threaded inbound run

…will not work.

What is viable

A human-assisted two-step handoff is viable:

1. user posts file + @agent in channel root
2. AGENTS.md tells the agent:
   • do not review yet
   • reply in a thread with something like:
     • “I created a review thread. Please reply here with @agent start review and I’ll begin.”
   • stop
3. user replies inside that Slack thread
4. now OpenClaw sees a real threaded inbound message
5. review runs in the thread-scoped session

That workaround is actually pretty reasonable.

Why this one is better

Because in that flow:

• the heavy review never runs in the channel main session
• the real review starts only once you are already in the thread
• you can probably leave inheritParent: false, which avoids dragging channel-session pollution into the thread

Also, for the first real thread turn, OpenClaw can seed context from the thread starter (root message), so the original uploaded file / starter message can still be relevant there.

So my recommendation

• No to “agent self-mentions itself to trigger the review”
• Yes to “agent asks the human to re-mention/reply in the new thread, then starts review there”

With your current config, since you have:

"thread": {
  "requireExplicitMention": true