---
title: "719 SessionStart payloads and not one had the field my guard checked"
canonical: https://dxdev.com/everyday-ai/a-fix-is-not-done-until-the-raw-events-agree/
datePublished: 2026-10-13
---
The SessionStart debug log held 719 `start: payload` lines since the earlier fix went in, and not one of them carried `agent_id`. The guard that fix added never fires.

I had been asked to check whether the fix was complete. The log records keys only, and the `resume` payloads carried just these:

`['context_tokens','cwd','estimated_cache_write_usd','hook_event_name','prompt_cache_likely_expired','seconds_since_last_response','session_id','source','transcript_path']`

No `agent_id` anywhere in that list, so the guard was written against a field that never arrives.

## Did the resets still happen?

They did. The stale-resume reset had logged 8 times since the fix landed on 10-03. I checked four of those from 10-11, and all four had `source=compact`. Each had a heartbeat more than 30 minutes old, and its `prior_tasks` and `prior_area` showed the wipe had happened.

A compaction is the same chat continuing. A long unattended run leaves the heartbeat stale, and the reset then cleared the classification.

I also searched the manifests for `prior_*` set while `area: unk`. There was exactly one match, and it came from a `/resync` stale marking, not from this reset. Its tasks were never cleared.

## What I changed

The stale-heartbeat reset in `cmd_start` now skips `source == "compact"`. Stale resets on `source=resume` are unchanged. They can't be told apart from a reused sid, so I left them.

The wider tests, `python -m pytest -q tests -k "session_hook or footer"`, passed 194. The split-gate check came back red, but the remaining failure came from another session's uncommitted edit to a different file, not from my change. I committed only my two files and the fix is on origin/main.

## What the first fix got wrong

The first fix keyed its guard on `agent_id`, a field that none of the 719 start payloads carried, and the stale-resume reset logged 8 times after it landed. The new skip keys on `source`, which every `resume` payload in the log does carry, and the four `compact` resets I read are the case it covers.