---
phase: 10-seeder-checksum-integration
plan: 01
subsystem: scripts
tags: [sha256, checksum, vision, seeder, parquet, telegram]

# Dependency graph
requires:
  - phase: 08-checksum-spike
    provides: PyO3 checksum bindings (compute_sha256_hex, verify_checksum_hex, parse_checksum_file_content)
  - phase: 09-verification-registry
    provides: ChecksumRegistry with add/save/has_verified API
provides:
  - SHA-256 checksum verification integrated into seeder Vision download pipeline
  - Retry logic (2 retries) with LOUD Telegram alerts on persistent failure
  - ChecksumRegistry persistence after each seeder run
  - Checksum pass/fail/skip counters in seeder state file
affects: [11-sweep, 12-heartbeat-telemetry]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Checksum verification as download wrapper: _download_and_verify_vision_day() wraps _download_vision_day_raw()"
    - "Thread-safe stats via threading.Lock for concurrent download workers"
    - "Batch registry save (after thread pool completes, not per-file)"

key-files:
  created:
    - tests/test_seeder_checksum.py
  modified:
    - scripts/tick_cache_seeder.py

key-decisions:
  - "Soft-skip on 404/timeout CHECKSUM (old data may not have checksums)"
  - "Batch registry save after thread pool -- not per-file (reduces I/O, per Phase 9 design)"
  - "_download_vision_day_raw() duplicates CSV parsing from _download_vision_day() to also return raw bytes"

patterns-established:
  - "Checksum verification wrapper pattern: download raw bytes, verify, then parse"
  - "Thread-safe stat counters with Lock for thread pool workers"

requirements-completed: [SEEDER-01, SEEDER-02, SEEDER-03]

# Metrics
duration: 6min
completed: 2026-03-26
---

# Phase 10 Plan 01: Seeder Checksum Integration Summary

**SHA-256 checksum verification wired into tick_cache_seeder Vision download pipeline with retry, LOUD alerts, and ChecksumRegistry persistence**

## Performance

- **Duration:** 6 min
- **Started:** 2026-03-26T05:30:58Z
- **Completed:** 2026-03-26T05:37:11Z
- **Tasks:** 1 (TDD: RED + GREEN)
- **Files modified:** 2

## Accomplishments

- Every Vision ZIP download now verified against .CHECKSUM file via Rust SHA-256 bindings
- Checksum mismatch triggers up to 2 re-downloads; persistent failure fires LOUD Telegram alert
- Successful verifications recorded in ChecksumRegistry (symbol, date, sha256, source=seeder)
- State file includes checksum_pass/checksum_fail/checksum_skip counters for monitoring
- 9 offline tests covering all verification paths (match, 404, timeout, mismatch, retry, registry, stats)

## Task Commits

Each task was committed atomically:

1. **Task 1 (RED): Add failing tests** - `9cdb17d` (test)
2. **Task 1 (GREEN): Implement checksum verification** - `4b6f286` (feat)

**Plan metadata:** (pending)

## Files Created/Modified

- `tests/test_seeder_checksum.py` - 9 offline unit tests for checksum verification integration
- `scripts/tick_cache_seeder.py` - Added `_verify_vision_checksum()`, `_download_vision_day_raw()`, `_download_and_verify_vision_day()`, `_download_and_verify_day_worker()`, plus ChecksumRegistry wiring in `_seed_symbol()` and `main()`

## Decisions Made

- Soft-skip on 404/timeout CHECKSUM: old Vision data may not have .CHECKSUM files, so we log and continue
- Batch registry save after thread pool completes (not per-file) to reduce I/O, consistent with Phase 9 design
- `_download_vision_day_raw()` duplicates CSV parsing logic from `_download_vision_day()` to also return raw bytes needed for checksum -- avoids modifying existing function signature for backward compat

## Deviations from Plan

None - plan executed exactly as written.

## Known Stubs

None - all data paths are wired end-to-end.

## Issues Encountered

- Ruff TRY400 lint: `logger.error()` in except block should be `logger.warning()` -- fixed inline

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- ChecksumRegistry is now populated by seeder runs, ready for Phase 11 (sweep) to query via `has_verified()`
- Checksum stats in state file ready for Phase 12 (heartbeat telemetry) to monitor
- Existing seeder functionality (REST fallback, boundary backfill, batch rotation) unchanged

## Self-Check: PASSED

- [x] scripts/tick_cache_seeder.py exists
- [x] tests/test_seeder_checksum.py exists
- [x] Commit 9cdb17d (RED) found
- [x] Commit 4b6f286 (GREEN) found

---

_Phase: 10-seeder-checksum-integration_
_Completed: 2026-03-26_
