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)

(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.
• 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.