spark-control/CLAUDE.md

# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Browser-based StartOS 0.4 package controlling a dual NVIDIA DGX Spark AI cluster: one-click vLLM model swaps, plus health, proxying, and APIs for speech (STT/diarization/TTS), embeddings, and redaction.

Subsystem guidance lives in `.claude/rules/` and loads when matching files are touched: `startos-package.md` (build/versioning, `package/**`), `fastapi-image.md` (dev server/env/layout, `image/**`), `redaction.md` (vendoring + test gates), `audio-speech.md` (parakeet patches, cluster-container footguns, audio testing). **Read `audio-speech.md` before touching the Sparks' containers over SSH** — ops sessions don't trip the path scoping.

## Stack

- Two halves, always coordinated:
  - `image/` — standalone FastAPI app (Python ≥3.11; UI on port 9999; vanilla HTML/CSS/JS).
  - `package/` — StartOS 0.4 wrapper (TypeScript) that ships the Docker image as an s9pk.
- Build host needs `start-cli`, Node ≥22 + npm, and Docker.
- Cluster runtimes live **on the Sparks, not in this repo** (`spark-vllm-docker`, the parakeet/kokoro/embeddings containers). This repo is the controller; it reaches them over SSH + HTTP.
- Sparks are ARM64 (GB10 Grace-Blackwell, sm_121, CUDA 13). Services: vLLM `:8888` (Spark 1); `parakeet-asr` `:8000`, Kokoro TTS `:8880`, bge-m3 embeddings + Qdrant (Spark 2). See `docs/` for API contracts.

## Commands (headlines — details in the scoped rules)

```bash
(cd package && make x86)                                  # build the s9pk; make install sideloads (restarts live service — ask first)
(cd image && uvicorn app.server:app --port 9999)          # local dev — needs env vars, see fastapi-image rule
(cd image && .venv/bin/python -m app.redaction.test_gateway)      # offline redaction suite 1
(cd image && .venv/bin/python app/redaction/test_scrub_leak.py)   # offline redaction suite 2
./scripts/test-audio-with-speakers.sh <audio-file>        # e2e audio — hits the LIVE cluster
```

## Layout

- `image/app/` — FastAPI app (`server.py` entry, routers in sibling modules, `static/` dashboard UI).
- `package/startos/` — StartOS manifest, interfaces, actions, version + release notes.
- `docs/` — `AUDIO_API.md`, `EMBEDDINGS.md`, `REDACTION_GATEWAY.md` (consumer-facing API refs; update with API changes).
- `README.md` (overview), `HANDOFF.md` (fresh-user install guide), `runbook.md` (ops notes), `known-issues.md`, `ROADMAP.md` (longer-term backlog — items move into "Current state" below when picked up).

## Conventions

- Every shipped change = version bump + release notes + rebuilt s9pk (version format `X.Y.Z:N`; details in the startos-package rule).
- Commit messages: `vX.Y.Z:N - short lowercase summary`. **Never add a Co-Authored-By / Claude attribution trailer.**
- The package owner is non-technical: explain infra effects in plain English and get an explicit go/no-go before mutating the cluster.
- New external-facing endpoints get documented in `docs/` and noted in release notes for downstream app developers (Recap Relay, Ten31 Transcripts, CRM, Signal Engine consume these APIs).

## Always / Never (cluster-wide)

- **Always** confirm with the user before swap/stop/restart of anything on the live cluster. Read-only probes and dry-runs are fine without asking.
- **Always** use the Spark's **IP** for HTTP probes — `.local` mDNS names can resolve IPv6-first and hang httpx (vLLM and friends bind IPv4 only). Never trust `.local` hostnames inside HTTP client code.
- **Always** pass `SSH_KEY_PATH` / `-i <key>` explicitly in scripted SSH; non-interactive shells have no ssh-agent identities.
- **Never** route audio or transcripts to cloud services — speech stays on the LAN. (Scrubbed text via `/scrub` is the only sanctioned path toward frontier models.)
- **Never** commit owner-specific hostnames, IPs, usernames, or names into package strings, UI text, or docs — this package gets shared; use placeholders (`<spark-1-ip>` style).
- **Never** install `cuda-python` in `parakeet-asr` — crashes real decode on this GPU/CUDA-13 stack; full story in the audio-speech rule.

## Current state

- **Working (v0.18.0:0, installed and serving):** swap dashboard; chat / transcribe / diarize(+chunk) / TTS proxies; embeddings + rerank + hybrid search (Qdrant); `/scrub` + `/rehydrate`; label-merge incl. dual-channel mode. Spark 2 audio stack is healthy (11k+ requests/12h, all 200).
- **In progress — Signal Engine "flakiness":** diagnosed, not a server bug — transient 1–4s unresponsiveness while the single GPU is continuously busy. Remedy is client-side; a drafted message (in-flight cap 2, hard ceiling 3 global across audio endpoints, retry-with-backoff on timeout/503) is with the owner to forward to that dev.
- **Decided, not implemented:** remote access stays WireGuard/Tailscale split-tunnel — no public interface, so no API auth built; an empirical concurrency sweep is offered but needs the owner's explicit OK in a quiet window.
- **Known limits:** `/health` blips while the GPU is busy (mitigated client-side); dual-channel can miss a quiet local word under loud remote bleed; the connectivity log misses sub-5s outages between 5s polls; diarizer caps at 4 speakers.
- **Repo wart:** commit `367d986` is labeled `v0.13.0:4` but actually contains everything through v0.18.0:0 — per-version commits for v0.14–v0.18 are missing. Keep commit messages accurate going forward.
- **Hosting:** repo pushes to the owner's self-hosted Gitea — remote `gitea`, branch `master`, over SSH (host alias + key live in the local `~/.ssh/config`; no owner-specific details belong in the repo). Push there after committing.
- **Next:** (1) owner forwards the concurrency note to the Signal Engine dev; (2) run the concurrency sweep if the dev wants the measured knee; (3) add the `--memory` cap to parakeet-asr via the Reapply-patches action; (4) pick the next item from ROADMAP.md.