# Shared stack · what Blocao and Transcript have in common

The two products share most of their stack. This file maps the shared vs distinct parts to inform engineering decisions and avoid duplication.

## Shared 100%

| Layer | Component |
|---|---|
| Hardware (router) | OpenWrt router |
| Hardware (compute) | RK3588 Cell |
| OS (Cell) | Balena |
| Network model | VLANs, firewall, DNS sinkhole |
| Broker | Mosquitto + bridge |
| Time sync | chrony with NTS |
| VPN | Tailscale |
| Configuration | GitOps |
| Hub | Same Hetzner bare-metal infrastructure |
| Auth | Keycloak on hub |
| Sovereignty model | Same VLAN/bridge/storage tiering |

## Shared with adaptation

| Layer | Component | What changes |
|---|---|---|
| **Console framework** | SPA shell + design tokens + LCARS chrome | Same shell; product-specific panels added |
| **Chat query UI** | Pattern with ghost-text autocomplete + agent pipeline | Vocabulary differs; layout identical |
| **Timeline** | Time-axis with markers + playhead | Marker semantics differ (event vs speech segment) |
| **Player** | Scrubber + correlated metadata + caption | Video player vs audio player; same shell |
| **Case management** | Pin-to-case, evidence pack export | Same model; different evidence types |
| **Embeddings store** | Qdrant | Same software; separate collections (visual vs voiceprint) |
| **Health** | Selftest engine | Mostly same checks; product-specific tests for STT readiness |
| **Evidence chain** | Hash + manifest + signature | Same flow; manifest schema differs slightly |

## Product-specific (Blocao)

| Component | Description |
|---|---|
| Frigate container | RTSP ingest + detection |
| Frigate enricher | CLIP embeddings, re-ID, hashing |
| Camera onboarding flow | Discovery, ONVIF, RTSP probe |
| Video clip storage tier | Hot NVMe + cold HDD |
| LPR / vehicle / animal classifiers | Specialized detection types |

## Product-specific (Transcript)

| Component | Description |
|---|---|
| Whisper container | STT engine |
| pyannote container | Diarization |
| Speaker library | Voiceprint storage and matching |
| Audio ingest interface | USB mic, line-in, SIP, file upload |
| Topic detection (NER + clustering) | Identifies subjects discussed |
| Insistence analyzer | Per-speaker intervention pattern analysis |

## Engineering implications

1. **The console framework is product-agnostic**. It should be designed as a shell that loads product-specific panels.
2. **The Cell stack is product-extensible**. The same Balena fleet can run Blocao containers, transcript containers, or both.
3. **The hub schema must accommodate both**. Site → Cell → Service → Capability hierarchy where Capability is `frigate | enricher | whisper | pyannote | re-id | ...`.
4. **GitOps repos are unified**. Both products share `fleet-config` for org-wide settings and `site-config` for per-site config.
5. **The MQTT contract has namespace separation**. Video events are `hai/<cam_id>/...`; audio events would be `aud/<source_id>/...`. Both follow the same patterns; bridge policy generalizes.

## Backlog implications

Stories that touch shared components are tracked in `backlog/shared-stories.md` to avoid duplicate work. The `BL-XX.Y` and `WDM-T-XX.Y` story IDs reference shared stories explicitly when relevant.

Sprint planning should sequence shared infrastructure (Sprint 0 + selected items from Epics 0-2-5-6) **before** product-specific work, so both products benefit.