mokosh/.planning/PROJECT.md

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

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

Active

• 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

• 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

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	AMENDED 2026-05-20 (Amendment 1) by Plan 02-03: SPEC §7 originally specified tabCapture, activeTab, downloads, scripting, storage + host_permissions: ["<all_urls>"]. Phase 01 retired tabCapture (DEC-003 Amendment) and added desktopCapture, offscreen, notifications. Amendment 1 (2026-05-20) ADDS tabs to enable chrome.tabs.get(tabId).url + chrome.tabs.query({}) for the Phase 2 D-P2-02 meta.urls feature (tab-url-tracker requires URL visibility beyond active-tab semantics). Current locked set: desktopCapture, activeTab, tabs, downloads, scripting, storage, offscreen, notifications + host_permissions: ["<all_urls>"]. Audit T-1-02 ("unused permissions expand attack surface") is acknowledged but overridden — the permission is genuinely USED by the meta.urls feature, so it is not unused. See .planning/phases/02-stabilize-export-pipeline/02-CONTEXT.md Revision Log.	— Pending	locked (Phase 1, post-Amendment 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