---
phase: 28-retroactive-sweep
plan: 01
subsystem: scripts
tags: [kintsugi, stathera, exchange-gap, parquet, checksum]

requires:
  - phase: 26-exchange-gap-classification
    provides: _repair_aion exchange gap classification logic, ChecksumRegistry, kintsugi_log exchange_gap result
provides:
  - Retroactive exchange gap sweep script for classifying existing 96K Stathera gaps
affects: [kintsugi, heartbeat-stathera]

tech-stack:
  added: []
  patterns: [retroactive classification reusing _repair_aion logic]

key-files:
  created:
    - scripts/retroactive_exchange_gap_sweep.py
  modified: []

key-decisions:
  - "Reused exact _repair_aion classification logic (checksum-verified Parquet + 0 trades in TID range)"
  - "Used action='retroactive_sweep' to distinguish from live classification in kintsugi_log"

patterns-established:
  - "One-time sweep scripts follow argparse --dry-run pattern for safe preview"

requirements-completed: [RETRO-01, RETRO-02]

duration: 1min
completed: 2026-03-28
---

# Phase 28 Plan 01: Retroactive Exchange Gap Sweep Summary

**One-time script classifying existing Stathera gaps as exchange gaps via checksum-verified Parquet with 0 trades in TID range, permanently dismissing them from kintsugi repair queue**

## Performance

- **Duration:** 1 min
- **Started:** 2026-03-28T01:01:38Z
- **Completed:** 2026-03-28T01:03:00Z
- **Tasks:** 1
- **Files modified:** 1

## Accomplishments

- Created retroactive exchange gap sweep script that reuses Phase 26 \_repair_aion classification logic
- Script discovers all Stathera shards, filters dismissed/overlap/genesis, classifies remainder via Parquet + ChecksumRegistry
- Supports --dry-run, --symbol, --threshold flags for safe targeted runs
- Logs exchange gaps to kintsugi_log with result='exchange_gap' and action='retroactive_sweep' for permanent dismiss

## Task Commits

Each task was committed atomically:

1. **Task 1: Create retroactive exchange gap sweep script** - `9ebfc86` (feat)

## Files Created/Modified

- `scripts/retroactive_exchange_gap_sweep.py` - One-time retroactive sweep script classifying existing gaps

## Decisions Made

- Reused exact \_repair_aion classification logic for consistency (checksum-verified Parquet + 0 trades in TID range)
- Used action='retroactive_sweep' to distinguish retroactive classification from live kintsugi classification in kintsugi_log
- Used assert isinstance for DataFrame type narrowing after \_select_trade_columns (returns LazyFrame | DataFrame union)

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Fixed type narrowing for \_select_trade_columns return**

- **Found during:** Task 1 (script creation)
- **Issue:** `_select_trade_columns()` returns `LazyFrame | DataFrame` union; `.is_empty()` not available on `LazyFrame`
- **Fix:** Added `assert isinstance(selected, pl.DataFrame)` after call since we pass DataFrame
- **Files modified:** scripts/retroactive_exchange_gap_sweep.py
- **Verification:** Type checker passes
- **Committed in:** 9ebfc86 (Task 1 commit)

---

**Total deviations:** 1 auto-fixed (1 bug)
**Impact on plan:** Type safety fix, no scope change.

## Issues Encountered

None

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- Script ready for production execution on bigblack with --dry-run first
- kintsugi_log exchange_gap entries will be picked up by \_get_dismissed_set() for permanent dismiss

---

_Phase: 28-retroactive-sweep_
_Completed: 2026-03-28_
