Description

When channels.slack.thread.inheritParent: true is configured, the parent message of a Slack thread is not being injected into the thread session context. This means replies within a thread have no knowledge of the original message that started the thread.

Steps to Reproduce

1. Configure Slack with thread isolation:

{
  "channels": {
    "slack": {
      "thread": {
        "historyScope": "thread",
        "inheritParent": true
      }
    }
  }
}

2. In a Slack channel, post a message mentioning the bot: @Bot who are you? Answer in one word.
3. Bot replies in thread: Stone
4. Reply in thread: Do another word.
5. Bot has no context of the original question — it doesn't know what "another word" refers to

Expected Behavior

With inheritParent: true, the thread session should include the parent message ("who are you? Answer in one word.") as context, so followup messages in the thread can reference it.

Actual Behavior

Looking at the session transcript (*-topic-*.jsonl), the first user message is the reply ("Do another word.") — the parent message is not present. The bot has to search memory/files to try to find context.

Environment

• OpenClaw version: 2026.1.29
• Channel: Slack (socket mode)
• Config: thread.historyScope: "thread", thread.inheritParent: true

Notes

The session key correctly creates isolated thread sessions (agent:main:slack:channel:<id>:thread:<ts>), but the parent message injection appears to not be implemented or is broken.