Summary
A long-running embedded/Paperclip agent session reached context overflow, auto-compaction retried three times, but the estimated prompt size did not decrease at all. The run remained at ~873k estimated prompt tokens against a ~242k prompt budget.
This looks like auto-compaction reporting attempts without actually reducing the selected prompt window for this session shape.
Environment
- OpenClaw:
2026.4.29 (a448042)
- Provider/model:
openai-codex/gpt-5.5
- Session key:
agent:roi-ceo:paperclip
- Node:
v22.22.2
- OS: Linux x64
Log excerpt
[context-overflow-diag] sessionKey=agent:roi-ceo:paperclip provider=openai-codex/gpt-5.5 source=promptError messages=49 sessionFile=/home/coolmann/.openclaw/agents/roi-ceo/sessions/9bbbe46d-d3af-486f-9f63-92b711c60d3d.jsonl diagId=ovf-mon4azsa-YdtnzQ compactionAttempts=1 observedTokens=unknown error=Context overflow: prompt too large for the model (precheck).
context overflow detected (attempt 2/3); attempting auto-compaction for openai-codex/gpt-5.5
[context-overflow-precheck] sessionKey=agent:roi-ceo:paperclip provider=openai-codex/gpt-5.5 route=compact_only estimatedPromptTokens=873084 promptBudgetBeforeReserve=242144 overflowTokens=630940 toolResultReducibleChars=0 reserveTokens=20000 effectiveReserveTokens=20000 sessionFile=/home/coolmann/.openclaw/agents/roi-ceo/sessions/9bbbe46d-d3af-486f-9f63-92b711c60d3d.jsonl
[context-overflow-diag] sessionKey=agent:roi-ceo:paperclip provider=openai-codex/gpt-5.5 source=promptError messages=49 sessionFile=/home/coolmann/.openclaw/agents/roi-ceo/sessions/9bbbe46d-d3af-486f-9f63-92b711c60d3d.jsonl diagId=ovf-mon4b3l8-X2J3QA compactionAttempts=2 observedTokens=unknown error=Context overflow: prompt too large for the model (precheck).
context overflow detected (attempt 3/3); attempting auto-compaction for openai-codex/gpt-5.5
[context-overflow-precheck] sessionKey=agent:roi-ceo:paperclip provider=openai-codex/gpt-5.5 route=compact_only estimatedPromptTokens=873084 promptBudgetBeforeReserve=242144 overflowTokens=630940 toolResultReducibleChars=0 reserveTokens=20000 effectiveReserveTokens=20000 sessionFile=/home/coolmann/.openclaw/agents/roi-ceo/sessions/9bbbe46d-d3af-486f-9f63-92b711c60d3d.jsonl
[context-overflow-diag] sessionKey=agent:roi-ceo:paperclip provider=openai-codex/gpt-5.5 source=promptError messages=49 sessionFile=/home/coolmann/.openclaw/agents/roi-ceo/sessions/9bbbe46d-d3af-486f-9f63-92b711c60d3d.jsonl diagId=ovf-mon4b7eg-Bk-OzQ compactionAttempts=3 observedTokens=unknown error=Context overflow: prompt too large for the model (precheck).
Session file shape
Local inspection of the JSONL session file showed:
size_bytes=17248811
lines=11546
roles={'session': 1, 'model_change': 1, 'thinking_level_change': 1, 'custom': 2252, 'user': 2272, 'assistant': 4687, 'toolResult': 2332}
Largest individual events were only around 20k chars, and the recent tail showed many repeated medium-sized wake/prompt/assistant/tool events, e.g. user events around ~2.4k chars and assistant events around ~1-3k chars.
So this was not one huge reducible tool result. It was accumulated conversation/session history that eventually made the selected prompt window enormous.
Expected behavior
When auto-compaction is attempted after a precheck overflow, one of these should happen:
- The selected prompt window is reduced below budget.
- The old session history is summarized/rotated/truncated according to policy.
- The run fails once with a clear actionable error instead of retrying identical oversized prompts.
Actual behavior
Auto-compaction attempted three times, but the next precheck still reported the same estimated prompt size:
estimatedPromptTokens=873084
promptBudgetBeforeReserve=242144
overflowTokens=630940
toolResultReducibleChars=0
Operational workaround
I archived the bloated local session file and replaced the active file with an empty one so the agent can start fresh:
~/.openclaw/agents/roi-ceo/sessions/archive-context-overflow-20260501/9bbbe46d-d3af-486f-9f63-92b711c60d3d.jsonl
That is a workaround, not a root-cause fix.
Impact
Long-running embedded/Paperclip agents can accumulate enough session history to become unrecoverable by normal auto-compaction. The logs imply compaction is happening, but no effective reduction occurs, which makes the failure hard to reason about operationally.
Summary
A long-running embedded/Paperclip agent session reached context overflow, auto-compaction retried three times, but the estimated prompt size did not decrease at all. The run remained at ~873k estimated prompt tokens against a ~242k prompt budget.
This looks like auto-compaction reporting attempts without actually reducing the selected prompt window for this session shape.
Environment
2026.4.29 (a448042)openai-codex/gpt-5.5agent:roi-ceo:paperclipv22.22.2Log excerpt
Session file shape
Local inspection of the JSONL session file showed:
Largest individual events were only around 20k chars, and the recent tail showed many repeated medium-sized wake/prompt/assistant/tool events, e.g. user events around ~2.4k chars and assistant events around ~1-3k chars.
So this was not one huge reducible tool result. It was accumulated conversation/session history that eventually made the selected prompt window enormous.
Expected behavior
When auto-compaction is attempted after a precheck overflow, one of these should happen:
Actual behavior
Auto-compaction attempted three times, but the next precheck still reported the same estimated prompt size:
Operational workaround
I archived the bloated local session file and replaced the active file with an empty one so the agent can start fresh:
That is a workaround, not a root-cause fix.
Impact
Long-running embedded/Paperclip agents can accumulate enough session history to become unrecoverable by normal auto-compaction. The logs imply compaction is happening, but no effective reduction occurs, which makes the failure hard to reason about operationally.