Result session persistence: 'I came back later and it wasn't there' (Tara Watson)

[MaxGhenis]

The user pain

At the 2026-04-21 working meeting (transcript lines 111-115), Tara Watson described running a simulation on policyengine.org, coming back later, and "it wasn't there." That's a first-order product bug with reproducibility implications — the researcher did the work; the work evaporated.

Policyengine-app #2830 scopes the future solution (TRACE "Cite this result" permalinks that resolve forever). But that is the long-tail answer. Tara's immediate pain is not yet addressed, and the transcript is specific about it: a researcher opened a result in a browser session, navigated away, came back, and could not get back to the same numbers.

Why this needs its own issue

It's distinct from #2830 in two ways:

1. Scope. TRACE "Cite this result" is about rigor for published papers. Tara's case is about session-level persistence for day-to-day work. The fix may be simpler — a stable URL that resolves to the same result across sessions — and should not wait on the TRACE backend.
2. Urgency. 'Cite this result' button, version badge, and shareable TRO permalinks #2830 is blocked on the pe.py v4 migration (api#3486 → api#3485 → app#2830). This could ship earlier.

Likely root causes to investigate

Without the full reproduction from Tara, candidates:

• Result caching in the app frontend that doesn't survive a browser restart.
• An api endpoint that doesn't accept a reproducing-request shape after cache expiry.
• A URL scheme that loses the reform/baseline/dataset pinning.
• Session state in localStorage that isn't written or isn't restored.

First step: get a reproduction from Tara. I'll email her to ask for the specific URL or workflow she hit, and what she saw when she came back.

Related

• 'Cite this result' button, version badge, and shareable TRO permalinks #2830 (long-tail TRACE "Cite this result")
• Add always-visible version badge on simulation result pages #2832 (version badge — distinct but adjacent)
• Meeting on 2026-04-21 with Tara Watson, transcript at /tmp/aea-review/transcript.txt:111-115 on this laptop

Scope

Not filing with a fix proposal yet — deliberately want the reproduction first. Putting this on the app-repo issue tracker as a user-reported bug with a clear source citation, so it does not get lost behind the bigger TRACE workstream.