Why does heartbeat need the whole session context?

[dim quest]

I'm confused about the heartbeat. Why does it need the whole context it if it's supposed to not "infer or repeat old tasks from prior chats"

[flint notch]

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[minor otter]

Short version: because heartbeat needs state, not because it should keep reviving old chats.

By default, heartbeat runs in the agent’s main session, so it can:

• see ongoing session state,
• notice completed background/system events,
• avoid duplicate nudges,
• and know where target: "last" should deliver.

But that line, “Do not infer or repeat old tasks from prior chats”, is a behavior rule, not a hard memory wipe. In other words, “you can see context, but don’t resurrect stale stuff just because it’s in the transcript.”

A couple important details:

• OpenClaw already filters out no-op heartbeat prompt/HEARTBEAT_OK pairs from history, so heartbeat noise is not supposed to pile up.
• If you want a much more stateless/cheap heartbeat, use:
  • heartbeat.isolatedSession: true = fresh session, no prior conversation history
  • heartbeat.lightContext: true = tiny bootstrap, basically just HEARTBEAT.md

So the real split is:

• default heartbeat: context-aware
• isolated + lightContext heartbeat: almost stateless

Docs:

• https://docs.openclaw.ai/gateway/heartbeat
• https://docs.openclaw.ai/concepts/system-prompt

If you want, I can also point at the exact code path where heartbeat history gets filtered.

[dim quest]

I don't agree. I don't use the main session at all but use a direct chat, the main session is just filled with HEARTBEAT_OK. It just takes so much time to process the useless context in the LLM. The heartbeat contains just a few standalone tasks

[minor otter]

Yeah, that’s a fair complaint. For standalone heartbeat tasks, I agree the shared-session default is kind of wasteful.

What’s happening today is:

• heartbeat turns still get stored in the transcript,
• HEARTBEAT_OK pairs are filtered when building model context,
• but the prompt line “do not infer or repeat old tasks” is still only a behavior hint, not a hard isolation boundary.

So if your heartbeat is just “run these few tasks”, the real fix is not the prompt text, it’s:

{
  agents: {
    defaults: {
      heartbeat: {
        every: "30m",

        isolatedSession: true,
        lightContext: true,
        target: "last"
      }
    }
  }
}

And if the destination is fixed, even better, use explicit target + to instead of last.

So bluntly: you’re right. That sentence does not solve token waste.
isolatedSession: true is the knob that actually stops heartbeat from dragging chat history along.

Docs:

• https://docs.openclaw.ai/gateway/heartbeat