metaharness

metaharness

Scaffold your own focused AI agent harness — like ruflo, uniquely yours.

Proven at the cost-Pareto frontier. Same "evolve the harness" thesis, measured: the Darwin harness resolves real SWE-bench Lite issues at 34.0% single-trajectory ($0.005/inst) and 39.7% Best-of-3 ($0.015/inst) — conformant, official harness. Live Cost–Performance leaderboard · @metaharness/darwin.

Published as metaharness (the metaharness and harness CLIs). Earlier versions were published as create-agent-harness.

Quick start

npx metaharness my-bot

You'll be prompted for template, host, description. Out comes a complete npm package ready to npm publish.

Non-interactive

npx metaharness my-legal-bot \
  --template vertical:legal \
  --host claude-code \
  --description "Contract redline + risk rating"

Templates

Template	Best for
minimal	Custom starter — kernel only
vertical:devops	Incident response, on-call workflows
vertical:support	Customer support, KB-RAG, escalation
vertical:trading	Quant trading (paper-default, circuit breakers)
vertical:legal	Contract review with citation checking
vertical:research	Multi-source dossier with evidence grading

Hosts

--host selects which host adapter ships with your harness:

Host	What you get
claude-code	.claude/settings.json with MCP + hooks
codex	~/.codex/config.toml with [mcp_servers.*]
pi-dev	Pi extension (TypeScript, no MCP by design)
hermes	cli-config.yaml + optional-mcps/*.yaml
openclaw	~/.openclaw/openclaw.json + workspace SKILL.md + install runbook
rvm	RVM partition manifest + capability table + wasm-guest + install runbook (hardware-isolated)

Multi-host: pass --host multiple times.

Also ships the harness CLI

harness sign      # produce/update the witness manifest
harness verify    # check signature
harness doctor    # smoke-check a scaffolded harness
harness help

Eject from ruflo

If you've been using ruflo and want your own focused harness from it:

npx metaharness --from-existing ./

Lifts agents/skills/commands, rewrites every ruflo / claude-flow reference, preserves attribution blocks marked with <!-- ruflo-attribution-block -->.

Full walkthrough

See USAGE.md.

License

MIT