openclaw - 💡(How to fix) Fix Dreaming diary (DREAMS.md) grows without bound — no rotation or size cap

Summary

The dreaming narrative phase appends diary entries to DREAMS.md on every cycle but never prunes, rotates, or caps the file size. Over time the file grows without limit.

Observed behavior

Two agents running for ~6 weeks both accumulated >130 KB dream diaries:

• Agent A: 134 KB (kagura, daily dreaming since mid-April)
• Agent B: 141 KB (ruantang, same period)

Impact

DREAMS.md is loaded as workspace project context and injected into every prompt. A 140 KB file significantly increases prompt size, adding latency and token cost to every turn — even for lightweight conversations that have nothing to do with dreams or memory.

Root cause

In dreaming-phases the narrative output is appended via replaceDiaryContent() (insert between start/end markers). There is no:

• Maximum file size or entry count check
• Rotation (e.g. keep last N entries or last N days)
• Archival of old entries to a separate file
• Any pruning mechanism

The only cleanup in the dreaming pipeline is session-store scrubbing (prunedEntries), not diary file management.

Suggested fix

Add a size or entry cap to the dream diary, for example:

1. Entry cap: keep the most recent N entries (e.g. 30), archive or discard older ones
2. Size cap: if DREAMS.md exceeds a threshold (e.g. 20 KB), trim oldest entries
3. Rotation: move old entries to DREAMS-archive-YYYY-MM.md (not loaded as context)

Any of these would prevent unbounded growth while preserving the dreaming feature.

Environment

• OpenClaw 2026.5.22
• Dreaming enabled with default config
• Two agents affected (different workspaces)