my main agent keeps openning the new session to spawn the sub-agent

[glossy granite]

what should I config to fix this problem?

[rustic cloak]

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[radiant sluice]

Sub-agents always run in a new internal session (agent:<agentId>:subagent:<uuid>). So seeing “it opened a new session to spawn a sub-agent …” is usually expected behavior, not a bug—your main chat session shouldn’t be replaced; the sub-agent just runs elsewhere and then “announces” back to the original channel.

What you can change depends on what you mean by “problem”:

1) If the debuggy/internal line is showing up in chat

That normally happens when verbose or reasoning is enabled for that session.

In the Discord chat where you see it, run:

• /verbose off
• /reasoning off

To make it default-off in config, ensure you have (in ~/.openclaw/openclaw.json):

{
  agents: {
    defaults: {

      verboseDefault: "off",
    },
  },
}

Docs: https://docs.openclaw.ai/help/faq#how-do-i-stop-internal-system-messages-from-showing-in-chat

2) If it’s creating new Discord threads/channels (not just internal sessions)

Then the agent is likely using Discord “threads” actions. Disable thread actions:

{
  channels: {
    discord: {
      actions: {

        threads: false,
      },
    },
  },
}

Docs: https://docs.openclaw.ai/channels/discord

3) If you simply don’t want sub-agents at all

Deny the sessions_spawn tool for that agent:

{
  agents: {
    defaults: {

      tools: {
        deny: ["sessions_spawn"],
      },
    },
  },
}

Docs: https://docs.openclaw.ai/tools/subagents

---

If you paste:

1. openclaw --version
2. a screenshot (or a couple lines) showing what exactly happens (new internal session vs new Discord thread/channel)