# Mokosh

## What This Is

Mokosh is a Chrome Manifest V3 browser extension that silently and continuously
records an operator's browser session — the last 30 seconds of active-tab video,
the last 10 minutes of DOM events (via rrweb), and the last 10 minutes of user
and runtime events — and, on a single button press, packages everything plus a
screenshot into a self-contained ZIP delivered to the user's "Downloads" folder
for handoff to support.

The name is taken from Mokosh (Мокошь), the Slavic goddess of fate and weaving:
each operator session is a thread she weaves into the archive.

## Core Value

When an operator hits a bug, one click MUST produce a self-contained archive
that lets support reproduce what happened — in under five seconds, with no
server involved, and with the operator's passwords never appearing in the
output.

## Requirements

### Validated

<!-- Shipped and confirmed valuable. -->

(None yet — Phase 1 of the SPEC ships from a partially-broken first attempt;
nothing is validated until SPEC §10 acceptance passes.)

### Active

<!-- Current scope. Building toward these. See REQUIREMENTS.md for IDs. -->

- [ ] Continuous 30 s active-tab video ring buffer (REQ-video-ring-buffer)
- [ ] 10 min / 5 000-event rrweb DOM buffer with sensitive masking (REQ-rrweb-dom-buffer)
- [ ] 10 min user/runtime event log with password filtering (REQ-user-event-log)
- [ ] One-shot screenshot at export time (REQ-screenshot-on-export)
- [ ] Russian-language popup with idle → "Сохраняю..." → "Готово! ✓" state machine (REQ-popup-ui)
- [ ] ZIP archive layout `session_report_YYYY-MM-DD_HH-MM-SS.zip` (REQ-archive-layout)
- [ ] `meta.json` schema (REQ-meta-json-schema)
- [ ] Exact manifest permission set per SPEC §7 (REQ-manifest-permissions)
- [ ] Click-to-download latency < 5 s (REQ-archive-export-latency)
- [ ] Passwords never appear in rrweb snapshots or event log (REQ-password-confidentiality)
- [ ] Extension installs unpacked into Chrome without errors (REQ-install-clean)

### Out of Scope

<!-- Explicit boundaries. Includes reasoning to prevent re-adding. -->

- Server upload of captured data — SPEC §9; reserved for Phase 2.
- AI-driven diagnostics — SPEC §9; reserved for Phase 2.
- Automatic ticket creation — SPEC §9; reserved for Phase 2.
- Analytics dashboard — SPEC §9; reserved for Phase 2.
- Audio recording — SPEC §9; reserved for Phase 2.
- Persisting rolling buffers to `chrome.storage` / IndexedDB — CON-buffer-storage;
  buffers are in-memory only in Phase 1.

## Context

- **Source documents:** Russian-authored SPEC (`Тз расширение фаза1.md`) and a
  Russian-authored README. All user-facing UI strings ("Сохранить отчёт об
  ошибке", "Последние 30 сек видео + 10 мин лога", "Сохраняю...", "Готово! ✓")
  are part of the contract and MUST be preserved verbatim. Section identifiers
  and code use Latin script.
- **Codebase state:** A partially-broken first attempt at the SPEC already
  exists under `src/` (background service worker, content script, popup) and
  `offscreen/`. An external audit identified 7 P0 defects that prevent SPEC §10
  acceptance. Phase 1 of this roadmap is remediation against the SPEC, not
  greenfield. See ROADMAP.md.
- **Operator context (SPEC §1):** Operators work inside a browser and
  periodically make mistakes that are hard to diagnose after the fact. The
  extension runs silently in the background; the operator only interacts with
  it when they need to file a report.
- **Build toolchain (DOC-only):** Vite + the `crxjs` plugin in TypeScript. The
  SPEC does not prescribe a build tool, so this is auto-overridable by a future
  ADR/SPEC.

## Constraints

- **Performance**: Click-to-archive-on-disk < 5 s (CON-archive-export-latency,
  SPEC §10 #6) — drives synchronous Blob assembly and avoidance of base64 data
  URLs.
- **Memory**: Background RAM ceiling 50 MB (CON-ram-ceiling, SPEC §10 #9).
  Expected steady-state is ~3–10 MB; the ceiling is a hard upper bound, not a
  target.
- **Video format**: `video/webm; codecs=vp9` @ 400 000 bps, `MediaRecorder`
  timeslice 2000 ms, single continuous recorder (CON-video-codec). The first
  chunk (WebM header) MUST be retained indefinitely (CON-webm-header-retention,
  DEC-009) — without it, the assembled file is not playable.
- **Buffer windows**: Video 30 s rolling, rrweb 10 min / 5 000 events whichever
  is tighter, user-event log 10 min (CON-video-window, CON-rrweb-window,
  CON-event-log-window).
- **Sensitive data**: ~~`input[type=password]` and `[data-sensitive="true"]` MUST
  be masked in rrweb (via v2 `maskInputFn`) AND the event logger MUST drop
  password field values (CON-sensitive-data-masking).~~ **DEFERRED 2026-05-20**
  per charter shift ("we don't care about privacy hardening. At least here.").
  Archive flow is internal-only (no external transmission); CON-sensitive-data-
  masking re-classified as Phase 4 optional hardening or v2 work. Operator-
  facing password masking remains a future polish item but is no longer v1-blocking.
- **Service Worker lifecycle**: MV3 SW unloads after ~30 s idle; a long-lived
  `chrome.runtime.connect` port from offscreen to SW emits a PING every 25 s
  to keep the SW alive (CON-display-capture-binding, AMENDED from
  CON-service-worker-keepalive).
- **Tab capture binding**: REMOVED (CON-tab-capture-binding RETIRED). The new
  `getDisplayMedia` binding (CON-display-capture-binding) is screen/window-
  scoped, not tab-scoped, and survives tab switches without re-attach.
- **Manifest permissions**: `tabCapture`, `activeTab`, `downloads`, `scripting`,
  `storage`; `host_permissions: ["<all_urls>"]` — exactly this set, no more, no
  less (CON-manifest-permissions).
- **Storage strategy**: All Phase 1 rolling buffers live in memory only
  (CON-buffer-storage). `chrome.storage` is permitted but MUST NOT be used to
  persist rolling buffers.
- **Network**: No server upload in Phase 1 (CON-no-server-upload). All export
  is local-only via `chrome.downloads`.

## Key Decisions

<!-- Decisions that constrain future work. All 12 below are SPEC-Accepted
     acting as ADR-equivalents for Phase 1 per orchestrator instruction. They
     are LOCKED for Phase 1: any change requires a formal ADR. None are
     formally LOCKED in the ingest classification — a future ADR can revise
     any of them, but Phase 1 implementation MUST treat them as locked. -->

| Decision | Rationale | Outcome | Status |
|----------|-----------|---------|--------|
| **DEC-001**: Chrome Extension Manifest V3 | SPEC §2, §7 — required for `chrome.tabCapture`, `chrome.downloads`, `chrome.alarms`. | — Pending | locked (Phase 1) |
| **DEC-002**: Service Worker as background coordinator | SPEC §2, §3, §8 — MV3 has no persistent background page; SW coordinates video buffer + archive packaging. | — Pending | locked (Phase 1) |
| **DEC-003**: Active video via `getDisplayMedia()` (vp9 / 400 kbps / 2000 ms) | AMENDED by Phase 01: SPEC §2/§4.1/§7 originally specified `chrome.tabCapture`; Phase 01 swaps to `getDisplayMedia` invoked in the offscreen document with `chrome.offscreen.Reason.DISPLAY_MEDIA`. Codec/bitrate/timeslice binding unchanged. See `.planning/intel/decisions.md` DEC-003 Amendment. | — Pending | locked (Phase 1, post-Amendment) |
| **DEC-004**: DOM capture via rrweb with 5 000-event cap. ~~`maskInputSelector` masking~~ DEFERRED 2026-05-20 — `maskInputSelector` was rrweb 1.x; v2.0.0-alpha.4 requires `maskInputFn`. Per 2026-05-20 charter shift, masking deferred to Phase 4 (optional) or v2; AMENDED to "rrweb 5000-event cap; masking deferred". | SPEC §2, §4.2 — rrweb is the only mature DOM-recording option; cap is part of the memory contract; masking originally part of privacy contract (deferred). | — Pending | locked (Phase 1, post-Amendment) |
| **DEC-005**: Archive packaging via JSZip | SPEC §2, §3, §6 — only ZIP library bundled per SPEC. | — Pending | locked (Phase 1) |
| **DEC-006**: File download via `chrome.downloads` | SPEC §2, §5, §7 — no server upload in Phase 1 (SPEC §9). | — Pending | locked (Phase 1) |
| **DEC-007**: In-memory buffers only (no Phase 1 persistence) | SPEC §2, §4.1–§4.3 — rolling buffers in SW (video) and Content Script (rrweb + log). | — Pending | locked (Phase 1) |
| **DEC-008**: Screenshot via `chrome.tabs.captureVisibleTab` | SPEC §4.4, §5 — captured at export time, not continuously. | — Pending | locked (Phase 1) |
| **DEC-009**: WebM header chunk retained indefinitely | SPEC §4.1, §8 — WebM without its header is not playable. | — Pending | locked (Phase 1) |
| **DEC-010**: Service Worker keepalive via long-lived port | AMENDED by Phase 01: SPEC §8 originally specified `chrome.alarms` at 20 s; Phase 01 swaps to a `chrome.runtime.connect` port between offscreen and SW with 25 s ping cadence and 290 s pre-emptive reconnect. See `.planning/intel/decisions.md` DEC-010 Amendment. | — Pending | locked (Phase 1, post-Amendment) |
| **DEC-011**: Manifest permissions set | SPEC §7 — `tabCapture`, `activeTab`, `downloads`, `scripting`, `storage` + `host_permissions: ["<all_urls>"]`. | — Pending | locked (Phase 1) |
| **DEC-012**: Vite + crxjs + TypeScript build toolchain | README §"Технический стек" — DOC-level only; SPEC does not prescribe. | — Pending | locked (Phase 1) — auto-overridable by future ADR |

## Success Metric (Developer-Facing)

Phase 1 is "done" when all **9 SPEC §10 acceptance criteria** pass against an
unpacked load of the build into Chrome:

1. Extension installs in Chrome without errors.
2. Video buffer runs continuously on any tab.
3. Buffer never holds more than 30 s of footage.
4. rrweb records DOM events without errors on typical pages (forms, tables,
   modals).
5. Event log captures clicks, navigation, and network errors.
6. Archive downloads to "Downloads" in < 5 s after button press.
7. Archive opens cleanly; `last_30sec.webm` plays back in a browser.
8. Passwords do not appear in the event log or rrweb snapshots.
9. Extension RAM consumption does not exceed 50 MB in the background.

The verbatim list lives in REQUIREMENTS.md under "Phase 1 Acceptance Criteria
(SPEC §10 verbatim)".

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*Last updated: 2026-05-15 after initial bootstrap from intel synthesis*