Pi Agent Harness (formerly badlogic/pi-mono; 108k+ stars, MIT/TypeScript). Not one CLI but layered packages usable on their own: pi-coding-agent (interactive coding agent), pi-agent-core (runtime with tool calling and state), pi-ai (unified multi-provider LLM API), plus chord composition runtime, pi-telemetry contracts, pi-durable persistence and pi-tui differential terminal rendering. The README states plainly that there is no built-in permission system and offers micro-VM / Docker / sandbox paths instead. Not benchmarked by us; graded needs-reproduction.