¬ just serendipity 🍀 (not just serendipity)

Problem statement: ctrl+d in pi took several seconds to quit.

The culprit was pi-memory’s session_shutdown handler. It sent one last LLM request to summarize the session, wrote its answer to the daily log, then ran qmd update. Pi awaits all shutdown handlers, correctly, so quitting waited for everything:

pi.on("session_shutdown", async (event, ctx) => {
  const result = await generateExitSummary(ctx);
  fs.writeFileSync(filePath, entry, "utf-8");
  await runQmdUpdateNow();
});

Making that promise fire-and-forget would not work: Pi exits immediately after shutdown, and either the in-flight request keeps Node alive or gets killed before it can write anything.

Instead, I made the shutdown path write a durable job, synchronously:

const job: ExitSummaryJob = {
  version: 1,
  id: randomUUID(),
  createdAt: new Date().toISOString(),
  date: todayStr(),
  reason,
  sessionId: shortSessionId(ctx.sessionManager.getSessionId()),
  conversationText: truncated.text,
  truncated: truncated.truncated,
  totalChars: truncated.totalChars,
};

const jobPath = path.join(
  EXIT_SUMMARY_JOBS_DIR,
  `${job.createdAt.replace(/[:.]/g, "-")}-${job.id}.json`,
);
fs.writeFileSync(jobPath, `${JSON.stringify(job)}\n`, { encoding: "utf-8", flag: "wx" });

The next interactive session starts an unref’ed worker. It atomically renames one job to claim it, generates summary with active model, writes it back to original day’s daily log, and deletes job. Failed jobs return to queue. A stale claimed job retries after ten minutes.

I kept upstream package intact by replacing it with a local package, effectively forking it:

% pi remove npm:pi-memory
Removed npm:pi-memory
% pi install ~/.pi/agent/local/pi-memory-async
Installed /Users/thiago.perrotta/.pi/agent/local/pi-memory-async
% pi list
User packages:
  local/pi-memory-async
    /Users/thiago.perrotta/.pi/agent/local/pi-memory-async

Jobs live in ~/.pi/agent/memory/exit-summary-jobs/. ctrl+d only writes one JSON file now; summary happens during next session, without blocking exits.

Source code: pi-memory-async.

🤖 Drafted with /bloggify.