HokusaiAgent

Claude Code plugin for the RIKEN HOKUSAI BigWaterfall2 (HBW2) supercomputer — submit and monitor Slurm jobs, manage files on the cluster, and search the official documentation, all from the agent.

HBW2 is a CPU-first system: the 312-node Massively Parallel Computer (MPC) and the large-memory server (LMC) do most of the work, with a small 4-node H100 GPU server for postprocessing.

Install

In Claude Code:

/plugin marketplace add RIKEN-RCCS/Hokusai-Agent
/plugin install hokusai@hokusai-marketplace
/reload-plugins

Then run /hokusai-demo to verify the connection end-to-end.

Configuration

Settings live in ~/.hokusai/config.json:

{
  "ssh": {"host": "hokusai"},
  "account": "RB999999"
}

• ssh.host is a ~/.ssh/config alias or user@hostname (key-based auth required; register your key on the HBW2 Portal). hokusai.riken.jp round-robins to hokusai1..4. The env var HOKUSAI_HOST overrides the file.
• account is your project ID (e.g. RB999999), required for job execution. A JobSpec can override it per job. HOKUSAI_ACCOUNT overrides the file.

For documentation search, add your API key for the shared RIKEN embedding service:

{
  "ssh": {"host": "hokusai"},
  "account": "RB999999",
  "embedding": {"api_key": "..."}
}

The env var RCCS_EMBED_API_KEY sets the key. With it, docs search uses semantic (vector) matching; without it — or off the RIKEN network — it falls back to BM25 keyword search over the same content.