# Validation: Event Log, Checkpoints, Memory and Deterministic Replay

## Окружение

| Параметр | Фактическое значение |
|---|---|
| Дата проверки | 2026-07-25 |
| Commit | Concurrent uncommitted workspace; base HEAD observed as `68582c97cb6b51804532cbd021290f07f4f74fa5` |
| OS и hardware | macOS 26.4 (`25E246`), arm64 |
| Runtime | Node.js `v24.14.0`, built-in TypeScript stripping |
| Внешние сервисы | `none` |
| Входные данные | Shared contract fixtures, seed `20260725`, owned short branch fixture and fixed 1,000-event runner |

## Результаты по критериям

| ID | Проверка | Ожидалось | Получено | Evidence | Результат |
|---|---|---|---|---|---|
| AC-01 | Append-only history and correction | Prior bytes unchanged; correction appends author/reason/reference | Stored clones resist mutation, duplicate append throws, original bytes/size unchanged. No correction event contract exists | Test 1, `E-004`, `E-011` | `partial` |
| AC-02 | Genesis replay | Complete live/replay equality and identical canonical hash | `deepEqual` succeeds and SHA-256 hashes match | Test 2, `E-007`, `E-009` | `pass` |
| AC-03 | Verified checkpoint authority | Valid accepted; tampered sequence/hash/state rejected before replay | All three tampered cases fail verification and `replayFromCheckpoint` throws; valid replay equals live state | Test 3, `E-007`, `E-009` | `pass` |
| AC-04 | Visibility after persistence/replay | Explicit actor allow-lists; zero unauthorized branch facts | Juno/Mara/Pax fact IDs match across live/full/checkpoint; Pax on separate branch cannot see galley branch fact | Test 4, `E-009` | `pass` |
| AC-05 | 1,000-event long gate | Same hashes, checkpoint evidence, privacy, branch chronology, primary references and measured duration | 1,000/hash/checkpoint/privacy/duration pass; branch chronology and primary-event references are not modeled by this fixture | Test 5, `E-008`–`E-011` | `partial` |

## Команды проверки

```bash
node --test RnD/technical/2026-07-25-event-log-memory-replay/prototype/event-log.verification.test.ts
npm run typecheck
```

Fresh isolated scoped result:

```text
tests 5
pass 5
fail 0
todo 0
```

Fresh root TypeScript result: exit `0`.

## 1,000-event report

Isolated AC-05 diagnostic:

```json
{
  "eventCount": 1000,
  "finalStateVersion": 1000,
  "finalStateHash": "bff5dbc7db58b470a29b17d68ae6ac61ad89571087bf42e22f1e898b245a5a1e",
  "fullReplayStateHash": "bff5dbc7db58b470a29b17d68ae6ac61ad89571087bf42e22f1e898b245a5a1e",
  "checkpointReplayStateHash": "bff5dbc7db58b470a29b17d68ae6ac61ad89571087bf42e22f1e898b245a5a1e",
  "fullReplayDurationMs": 61.444584,
  "checkpointReplayDurationMs": 60.315583,
  "checkpoint": {
    "sequence": 500,
    "stateVersion": 500,
    "stateHash": "12e0b00ce5ff0efecb18d49c5ed14ea262d6969c73fa5002381f573693fd9f3e",
    "verified": true
  },
  "privateProjectionLeakage": false
}
```

Durations are one-machine observations, not acceptance thresholds.

## Ошибки и нестабильность

- An intermediate executable test proved that the old direct checkpoint helper
  could accept an unverified checkpoint. The shared entry point was changed so
  verification is mandatory; the adversarial test now passes.
- Replay durations vary between runs and are intentionally non-binding.
- No test flake or failure remained in the final scoped/root checks.

## Воспроизводимость

The 1,000-event fixture uses deterministic seed `20260725`, alternating
`check`/`end_turn` commands and checkpoint sequence `500`. The diagnostic emits
all final hashes and durations. The owned short fixture uses 12 events,
checkpoint 6 and an explicit Pax branch split for the visibility oracle.

## Финальный исход

- **Outcome:** `partial`
- **Обоснование:** deterministic replay, checkpoint enforcement and visibility
  pass, including the fixed 1,000-event hash proof. Correction-event semantics
  and the long fixture's branch-chronology/primary-reference requirements remain
  unimplemented.
- **Что результат не доказывает:** persistent durability, cross-runtime hashes,
  correction authorization, retrieval recall, production performance or
  long-campaign product quality.