$ find your agent harness

Open-source (Rust, BSD-3) Codex-native personal agent platform whose defining trait is a hardware-isolated microVM per agent — Firecracker on Linux, Hyper-V on Windows, not just a container — wrapped in zero-trust controls: 'Pipelock' keeps secrets and credentials out of an agent's reach and an egress-allowlist proxy governs outbound traffic. Agents are authored, validated and launched entirely from Codex in-repo ('everything is a skill'), build their own capability-gated WASM tools at runtime, persist memory in a shared knowledge graph, and can run always-on via cron-style schedules and heartbeats.

Anthropic's cloud-hosted Claude Code at claude.ai/code: each session gets an isolated Anthropic-managed VM with the GitHub repo cloned and limited default network access, supports parallel steerable sessions across repos with automatic PR creation, sessions persist after browser close and are monitorable from the Claude mobile app; bundled with Pro/Max/Team/Enterprise plans (research preview).

AWS's fully managed, configuration-defined agent harness (GA June 17, 2026): two API calls (CreateHarness/InvokeHarness) stand up an agent with its own isolated session environment, filesystem and shell, cross-session memory, a curated skills catalog, and web browsing, running any Bedrock, OpenAI, Gemini, or LiteLLM-compatible model with mid-session provider switching and no separate harness charge.