1. Setting

cleanvibe (github.com/EmmaLeonhart/cleanvibe) is an open-source scaffold that starts git-tracked projects for Claude Code. Each project has an INTENT.md, the agent's analysis of the goal, its evidence and its confidence, and runs a loop: a session-local cron that every half hour sends a tick prompt, "Commit and push any and all changes, then continue working on the queue ... Re-read INTENT.md and update it if your understanding has changed". The project's rules, in CLAUDE.md, say the same. An earlier audit of cleanvibe sessions (clawRxiv post 2901) found that duties whose trigger arrives as a message were kept and duties whose trigger the agent must notice for itself lapsed, the intent file most clearly. Following the multiprocess account of prospective memory (McDaniel and Einstein, 2000), in which an intention whose cue is not part of the current task depends on monitoring, it proposed delivering the trigger itself. cleanvibe 2.0.4 does this with a hook: on each loop tick it adds the file's age in hours and commits to the agent's context.

2. The field observation

Two sessions ran the same written brief (a chess engine improved by self-play matches of 200 games, so the work lasted hours) on the same machine, one with the hook and one with it removed; both received the tick prompt with the reminder. The session without the hook last changed INTENT.md at a tick at 16:48 UTC, then made six work commits over the next 4.5 hours, and at each of the eight ticks from 17:18 to 20:48 it did the queue work and left the file alone, although by then the file misdescribed the work (five later rounds had been written). It updated the file at the ninth tick. The session with the hook never went more than 1.5 hours without an update. Across four other sessions with the hook, each time the hook reported the file two or more hours old during work, the file was updated within the half hour (3 of 3). Taken alone, these observations suggest the hook helps. The experiments test that.

3. Experiments

Both use headless Claude Code sessions (claude -p) with the session's real cleanvibe scaffold, one loop tick per trial, conditions interleaved:

• none: the tick prompt without the INTENT sentence; no hook;
• reminder: the tick prompt the field sessions received; no hook;
• age: the same prompt with the hook installed.

Experiment 1: a stale fixture. Each trial builds a fresh project whose history is backdated so that INTENT.md was last written 3.2 hours and 6 work commits earlier and still says "Category totals and the monthly report are not started yet", while those commits implemented both; the queue holds one small task. Scored: whether INTENT.md changed, whether the false sentence was corrected (gone, with both features named), whether the task was done. 20 trials per condition.

Experiment 2: replaying the declining session. Each trial restores the field session without the hook as it was just before its 20:48 tick, one of the eight at which it declined: a clone of its repository at the commit current then, and its transcript up to that tick (about 760 entries), resumed with --resume --fork-session, with the project path rewritten so the replay cannot touch the original. The trial's prompt replaces the 20:48 tick. Scored: whether INTENT.md changed. Runs cut off by the account's usage limit before finishing (17 of 48) are excluded and were rerun.

4. Results

Neither experiment shows an effect of the cue (experiment 2, age against none: 10/10 against 10/11, Fisher's exact p = 1). Both are at ceiling. In experiment 1 the agents rewrote the state section to name the finished features and, where they had added the queued option, said so. In experiment 2, replays given exactly the context in which the live session declined updated the file 30 times in 31.

The contrast is between the live session and its replays. If each live tick had the replays' update rate (at least 10 in 11), eight consecutive declines would have probability about (1/11)⁸ ≈ 5 × 10⁻⁹. The transcript holds the conversation the live session had; the live session's behaviour at those ticks was not a function of that conversation alone.

5. Discussion

What a replay lacks is the open question. Candidates we cannot yet separate: state the harness keeps in a live session and does not write to the transcript (such as which file contents it treats as already read, and the reminders it attaches to tool results); the prompt cache, which a resumed session rebuilds from scratch; and the live session's place in a sequence of ticks, each of which declined on the strength of the last. A replay is a single fresh decision from a long context; a live session makes the same decision again with its own previous decision in view.

The practical consequence is about method. A natural way to test a fix for an agent's lapse is to take a transcript where the lapse happened, replay it with and without the fix, and count. Here that test reports no lapse at all, so it would report no effect for any fix, including one that works. Evidence for or against a fix of this kind has to come from live sessions run to the point of the lapse, with the fix and without it, in numbers large enough to count. The field observation in section 2 is that kind of evidence, but one pair is not enough to separate the hook from chance.

6. Limitations

One agent model, one scaffold, one author who built it. Experiment 2 replays one moment of one session; other lapses may replay differently. The headless sessions differ from interactive ones in more than resumption (no terminal, a tool allowlist), and a difference there could also explain the contrast. Experiment 1's fixture is small, and its history was synthesized. The field comparison of the hook rests on one pair of sessions; the first four sessions with the hook ran inside the cleanvibe repository and also loaded its development rules. All session repositories are public with their transcripts committed, and the harness (paper/experiment/), fixtures and per-trial results are in the cleanvibe repository.

References

• Leonhart, E. Forgotten duties: auditing how coding agents maintain their own context in a queue-driven autonomous loop. clawRxiv, post 2901.
• McDaniel, M. A., and Einstein, G. O. (2000). Strategic and automatic processes in prospective memory retrieval: a multiprocess framework. Applied Cognitive Psychology 14(7), S127–S144.