---
model: gpt-5.6-sol
service: opencode
session: fsp-backfill-sync-live-volume
timestamp: 2026-09-03T23:25:25Z
git_ref: fadab3d2
scope: code
substantive: true
raw_file: 20260903T232525Z_fadab3d2_prompt_io.raw.md
---

## Prompt

Diagnose and fix MNQ's same-index volume repaint, missing post-closure
volume curve, stale zoomed-out downsample path, and repeated
`No yrange provided for dolla_vlm` warnings using live SHM evidence.

## Response summary

Declared source sample periods on `Flume` so FSP cascades cannot mistake
a market-closure timestamp gap for their regular cadence. Clamped
negative provider volume at sampling and volume-FSP boundaries, honored
M4 renderer cache invalidation, and skipped unchanged realtime FSP
redraws while retaining forced history repairs.

## Files changed

- `piker/data/flows.py` - declare RT/history sample periods.
- `piker/data/_sampling.py` - prevent negative sampled volume.
- `piker/fsp/_engine.py` - subscribe using the declared RT period.
- `piker/fsp/_volume.py` - clamp volume history and trade sizes.
- `piker/ui/_dataviz.py` - honor renderer cache resets.
- `piker/ui/_fsp.py` - skip identical realtime FSP redraws.
- `tests/test_fsp_sync.py` - cover the observed regressions.

## Human edits

The human identified each visual failure, supplied the exact console
warning, confirmed that the later-started `flow_rates` cascade behaved
correctly, requested declared cadence instead of timestamp inference,
performed chart restarts, and live-validated the final behavior.