The OpenClaw runtime family: OpenClaw vs NanoClaw vs PicoClaw

A short primer for understanding the three OpenClaw-family agent runtimes ClawMetry observes, and how they differ. Written for someone who knows OpenClaw and wants to place NanoClaw and PicoClaw next to it. Facts here were verified by reading each project's source and (for NanoClaw / PicoClaw) by actually installing and running them; see tests/fixtures/runtimes/<rt>/REAL/PROVENANCE.md.

One line each

• OpenClaw: the original "personal AI assistant, any OS, any platform." The reference runtime; everything else in the family is a re-imagining of it.
• NanoClaw: "OpenClaw, but each agent runs in its own container for security." Same messaging-assistant idea, hardened isolation, built on Anthropic's Agents SDK.
• PicoClaw: "OpenClaw, but tiny and deployable anywhere." A single Go binary small enough to run on a $10 board (Raspberry-Pi-class), with 30+ LLM providers.

At a glance

	OpenClaw	NanoClaw	PicoClaw
Repo	openclaw/openclaw	nanocoai/nanoclaw	sipeed/picoclaw
Site	openclaw.ai	nanoclaw.dev	picoclaw.io
Stars (2026-05-25)	~374K	~29K	~29K
Language	TypeScript	TypeScript	Go
License	MIT	MIT	MIT
Pitch	Reference assistant	Container isolation	Tiny / runs anywhere
Isolation	App-level permission checks	OS-level Docker container per agent	Workspace path restriction
Default model	Hosted (Anthropic, etc.)	Hosted Claude via Agents SDK	Pluggable; ships hosted default, local (Ollama) opt-in
Best for	Daily driver on a real machine	Security-sensitive / multi-agent	Edge / low-power / cheap hardware

How they store a session (the part that matters most)

This is where they genuinely diverge, and it is why ClawMetry needs a separate reader for each. "Shares the OpenClaw layout" is a myth: only OpenClaw uses the OpenClaw layout.

OpenClaw: v3 JSONL, one file per session

~/.openclaw/agents/main/sessions/<session_id>.jsonl

Each line is a v3 event envelope: {"type":"message","message":{"role","model", "usage":{"totalTokens",...,"cost":{"total"}}, "content":[ blocks ]}}, plus session, model_change, tool_use_result lines. Tokens and pre-computed cost are written to disk. Gateway: WebSocket JSON-RPC on port 18789.

PicoClaw: flat JSONL, OpenAI-style messages

~/.picoclaw/workspace/sessions/<key>.jsonl   (+ <key>.meta.json sidecar)

Each line is a flat providers.Message: {"role","content" (a string), "model_name","created_at","tool_calls":[{"function":{"name","arguments"}}]}. No type, no message wrapper, tool calls are OpenAI-nested, and no token or cost field is written to disk. Crons live in workspace/cron/jobs.json (schedule.{kind,expr}). Gateway on port 18790. Home is $PICOCLAW_HOME (default ~/.picoclaw).

NanoClaw: per-session SQLite, two databases

<checkout>/data/v2-sessions/<agent_group_id>/<session_id>/
    inbound.db    (host writes, container reads)
    outbound.db   (container writes, host reads)

Not JSONL at all. inbound.db holds messages_in, outbound.db holds messages_out + session_state. A transcript is the two tables merge-sorted by a shared seq (host writes even, container writes odd). The data dir is relative to where NanoClaw was launched (its README clones to e.g. ~/nanoclaw-v2 and runs from there), so there is no ~/.nanoclaw and no env var. No model / token / cost columns: usage lives in the Agent SDK transcript inside the container, which is summarized then rotated, so it never lands on the host disk.

What this means for cost/token visibility

• OpenClaw: full token + cost per turn (on disk). ClawMetry shows everything.
• PicoClaw: transcripts, model, and tool calls, but tokens/cost are not on disk, so ClawMetry honestly reports them as unavailable. (Local Ollama models are genuinely $0/token anyway; you pay in hardware + power.)
• NanoClaw: transcripts and message counts; model/tokens/cost are not on the host, so they show as unavailable until a future reader taps the SDK event log.

Try it yourself (what we did)

• PicoClaw (easiest full run): brew install go, clone sipeed/picoclaw, make build, point it at a local Ollama model (ollama run llama3.2 first), and picoclaw agent -m "...". Sessions appear under ~/.picoclaw/workspace/sessions/. go install does not work (the module pins a fork via a replace directive), so build from source.
• NanoClaw: clone nanocoai/nanoclaw, npm install && npm run build, follow its README (./nanoclaw.sh); it provisions per-session SQLite under data/v2-sessions/. A full live agent turn needs Docker + an Anthropic key.

How ClawMetry observes them

ClawMetry ships a dedicated reader adapter per runtime (clawmetry/adapters/{openclaw,picoclaw,nanoclaw}.py) that translates each native format into one unified session/event shape, so the dashboard treats them uniformly. When a runtime's data is present on a node, the sync daemon detects it and the cloud Runtime panel labels the node with its runtime alongside OpenClaw. See docs/compatibility.md, docs/PRD_PICOCLAW.md, and docs/PRD_NANOCLAW.md for the support matrix and the per-runtime deep dives.