nexa/docs/11-open-questions.md

# 11 — Open Questions (user-info-required)

Items that **block progress** and need a human decision before a workflow can be implemented or a service deployed. Tick them off as you decide.

## Resolved

- [x] **Q1 — Graph DB choice → Ontotext GraphDB (SPARQL).** Rationale: explore Nexa's memory through SPARQL is a stated goal. [08-graphrag-architecture](./08-graphrag-architecture.md) is rewritten accordingly.
- [x] **Q2 — Vector store → reuse `qdrant_scientific`** with a `nexa_*` collection prefix. No dedicated container.
- [x] **Q3 — Embeddings model → not OpenAI.** Self-host on the docker host via **TEI** (HF `text-embeddings-inference`) — Rust single-binary, OpenAI-compatible, ~500 MB image, no LLM runtime overhead. Speed analysis in §"Speed budget" below.
- [x] **Q5 — Display name → Karakeep.** The Zoraxy host alias `hoarder.nuclide.systems` is legacy — keep it for compatibility, but all docs, prompts and new workflow nodes use "Karakeep".
- [x] **Q13 — Octoprint container is *intentionally* temporary.** Suppress from Phase-5 monitoring: container-up/down alerts must skip names matching `octoprint*` (or any container tagged `proxmox-he 3d-printing`).
- [x] **Q14 — Homepage Zoraxy widget → no such widget.** Config error in `homepage/services.yaml`; cosmetic, not Nexa-related.
- [x] **Q15 — Embeddings staging plan → A now, C prepared.**
  - **Phase 3.1 (now)**: TEI + `BAAI/bge-m3`, single collection `nexa_knowledge_text` (1024-dim). DE/EN multilingual, fits the corpus.
  - **Phase 3.2 (later)**: swap TEI → `infinity`, add `jinaai/jina-clip-v2` (768-dim), second collection `nexa_knowledge_visual`. Backfill from the queue (see Q16).
  - All schema fields needed for 3.2 (`modality`, `media_uri`, `graph_iri`, `nexa:pendingVisualIndex`) are introduced **now** so 3.2 is purely additive — no rename, no migration. See [`qdrant_schema.json`](../nexa-core/config/qdrant_schema.json) and [`qdrant_schema_visual.json`](../nexa-core/config/qdrant_schema_visual.json).
- [x] **Q16 — Image-attachment queue ergonomics → leave bytes at source, reference by `media_uri`.** Zero copy. Memos attachments stay in Memos's data dir, Nextcloud images stay in Nextcloud, Obsidian images stay in the `Notizen` folder; the Phase-3.2 backfill workflow fetches them on demand via the URI scheme.
- [x] **Q17 — Immich out-of-band.** Nexa does not call the Immich smart-search API. Photo-library queries stay inside Immich.
- [x] **Q18 — SAIA proxies an embedding model, but 10 msg/min rate limit makes it unusable for ingest.** A 2 k-note Obsidian backfill would take ~3.3 h; real-time `#nexa:ask` would queue for tens of seconds during a writing burst. **Decision: deploy TEI as planned.** SAIA embeddings remain available as a manual fallback (e.g. for one-off `#nexa:learn` calls where rate is irrelevant).
- [x] **Q19 — Storage convention is plain host bind-mount of `/mnt/pve/unas/services/<svc>/<vol>`.** Karakeep stack confirmed: no driver opts, no CIFS, no per-volume credentials. Secrets via `env_file: .env` next to the compose. The earlier SMB-as-docker-volume proposal in this repo is withdrawn ([12/#27](./12-optimization-opportunities.md#27)) — it was over-fitting to the Nextcloud-specific NFS issue (Nextcloud's setup tooling chowns to `www-data` and fails on `root_squash`-style exports; that doesn't apply to normal containers). Nexa stack updated in [docs/09 §Step 3](./09-deployment.md#step-3--self-hosted-embeddings-tei).
- [x] **Q4 — Obsidian sync via Nextcloud WebDAV.** Confirmed the vault is `nc.nuclide.systems/Notizen/` (multi-device sync via Nextcloud client). Nexa accesses it through WebDAV (`/remote.php/dav/files/<user>/Notizen/`) reusing the existing `NC_APP_PASSWORD` — no filesystem mount, no LXC-to-LXC privilege escalation. Phase 3.1 polls every 15 min; an upgrade to Nextcloud's `notify_push` for sub-second updates is captured as optimization #15. Ignore list (don't index):
  - `.copilot/`, `.copilot-index/` — Obsidian Copilot's own embeddings cache.
  - `.smart-env/` — Smart Connections / Smart Composer plugin data (~13 MB).
  - `.caldav-sync/` — calendar sync, not notes.
  - `assets/` — 186 MB of binaries; routed through the Phase-3.2 visual queue (`nexa:pendingVisualIndex`), not the text path.
  - `Templates/` — empty templates, low semantic value.
  - `BMO/`, `Excalidraw/` — plugin folders.
  Anything else under `Notizen/**/*.md` is fair game.
- [x] **Q6 + Q7 — Lists & calendars discovered by name, not ID. Self-healing.**
  Confirmed names from screenshots:
  - **Tasks**: `Persönlich` (14), `DLR` (13), `Einkaufsliste` (13), `Wunschliste` (9).
  - **Calendars**: `Persönlich`, `DLR`, `Einkaufsliste`, `Wunschliste` (Nextcloud Tasks is calendar-backed, so the names are shared; Tasks lives on the calendar of the same name).
  - Mapping in classification: `DLR` = Work-Kontext, `Persönlich` = Personal-Kontext, `Einkaufsliste` = Shopping, `Wunschliste` = Wishes.

  **Self-healing requirement (the user explicitly noted lists may change/grow):** Nexa must not cache IDs forever. The `#nexa:config` workflow runs (a) on demand, (b) once daily as a scheduled refresh, and (c) automatically as a retry whenever a list/calendar lookup returns 404 or "not found". The runtime-config record in Qdrant's `_config` namespace stores `{name → id, discovered_at}` and gets invalidated on cache-miss. New lists added in Nextcloud surface in the next scheduled refresh and Nexa starts honouring `#einkaufsliste` / `#dlr` etc. without code changes.

- [x] **Q8 — Mail via Nextcloud, single account `fkrebs@nucli.de`.** No extra IMAP entry. n8n's IMAP node uses the same server credentials Nextcloud Mail already holds for that account; Nexa never sees a second password. Folders confirmed: `Posteingang` (default), `Archiv`, `Junk` (61 — auto-filtered, ignored by Nexa), `Papierkorb`, `Waiting`. The `Waiting` folder is a useful manual signal — items moved there by the user are skipped from digest (treat as "in flight").

- [x] **Q9 — Pocket-ID SSO is configured everywhere.** No separate auth for Nexa: Memos / n8n / future Nexa dashboard authenticate humans via Pocket-ID at the Zoraxy layer. Machine-to-machine calls (n8n → Memos webhook, n8n → Nextcloud, n8n → Qdrant, n8n → LiteLLM) keep using API keys / app passwords — SSO is for human UIs only. Don't add basic-auth or per-app login screens.

  This **resolves Q10 too** (the proposed "Pocket-ID SSO in front of n8n / Memos" is already done; Nexa just inherits it).

- [x] **Q10 — folded into Q9.**

## Hardware / capacity

- [x] **Q11 — Capacity confirmed from Proxmox node + LXC summaries.**
  - **Host (NUC 14 Pro)**: 22 threads (Intel Core Ultra 7 155H, 1 socket), 62.12 GiB RAM, 1.64 TiB disk (0.35% used). Steady state: 32.4 GiB used (≈24 GiB of which is ZFS ARC), load avg 1.99 / 1.39 / 1.15, IO delay 0.04%.
  - **LXC 104 (docker, unprivileged)**: 16 CPU, **31.25 GiB RAM cap (7.86 GiB used = 25%)**, 8 GiB swap (idle), **200 GiB boot disk at 47.7% used (~95 GiB)**. Tag `proxmox-helper-scripts`. Intel iGPU passthrough configured but currently failing — see [12/#26](./12-optimization-opportunities.md#26).
  - **RAM headroom is comfortable**: Phase-3 budget (~7 GiB additional — Qdrant ~1.5 + TEI/bge-m3 ~1.1 + GraphDB 4-GB heap + later +infinity/jina-clip-v2 ~1) fits inside the existing LXC cap with ~16 GiB still free. Levers if needed: (1) raise the LXC cap (host has plenty), (2) cap `zfs_arc_max` lower (ARC currently 24 GiB). Either is one line of config.
  - **Disk is fine** — the LXC also NFS-mounts the UNAS at `/mnt/pve/unas` (19.4 TiB total, 16.3 TiB free). Large/persistent volumes (Qdrant data, GraphDB repo, snapshots, image bytes if we ever stage them) bind-mount there; the 200 GiB local boot disk only carries images and small ephemeral state. See [12/#27](./12-optimization-opportunities.md#27).
  - **Verdict: no blockers for Phase-3.1.** Revisit once 3.4 GraphDB lands.
## Backups

- [ ] **Q12 — S3 archive bucket** (warm tier). `s3.nuclide.systems` is up. Bucket name + access key for Qdrant snapshots, GraphDB exports, and as the rsync source for the cold-tier copy.
- [ ] **Q20 — Off-site cold-tier backup provider.** `s3.nuclide.systems` is on-site only, so today the homelab has no real disaster-recovery copy (fire / theft / ransomware kills it). Comparison + recommendation in [docs/12 #37](./12-optimization-opportunities.md#37). User's stated candidate is **Jottacloud Unlimited** (~€9.50/mo, EU/Norway, soft-cap ~5 TB — comfortable for the next ~10 years given current 2 TB and slow growth). Alternatives: Hetzner Storage Box BX21 (€13/mo, predictable quota), Backblaze B2 (~$12/mo, US, S3-compatible). **Always encrypt before upload** with `restic` or `rclone crypt` regardless of provider. Decision needed: pick one, create the account, share account email here (no password). Once chosen, optimization #37 can be implemented end-to-end.

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## Speed budget (Q3 follow-up)

Workload measured against the **LXC 104 cap** (16 CPU, 31.25 GiB RAM — host has 22 threads / 62 GiB if we ever raise the cap):

| Task | Volume | Latency target | Achievable on CPU with `bge-m3` | Achievable with `nomic-embed-text` |
|------|--------|----------------|---------------------------------|------------------------------------|
| Real-time memo embed | 1 doc | <500 ms incl. n8n round-trip | ✅ ~50–100 ms | ✅ ~20 ms |
| Daily ingest | ~70 docs | <60 s | ✅ ~5–10 s | ✅ ~2 s |
| Obsidian backfill (one-shot) | ~2 000 docs | <15 min | ✅ ~2–4 min | ✅ <1 min |
| RAG query embed (`#nexa:ask`) | 1 doc | <300 ms | ✅ ~50 ms | ✅ ~20 ms |

Conclusion: CPU-only TEI is sufficient — no GPU needed for current scope. Bottleneck is SAIA chat (already remote), not embeddings. SAIA's own embedding endpoint is rate-limited to **10 req/min** which would block real-time embed; self-hosted TEI side-steps that completely.