AI Agent HarnessesWhere your agent actually lives

Claude Code runs in a terminal or inside Claude Desktop, reads and writes real files, runs real commands, and schedules recurring work. It defined the skill format that the other harnesses on this page read, which is why it is the reference implementation for most operator kits published today.

OpenAI's agent harness is capable, especially on code heavy work, and the natural pick when the whole team already runs on OpenAI. The Claude Code skill format works there with minor adjustment.

OpenCode is open source and model agnostic, which is its actual pitch: point it at different models and keep the working setup you already have. Worth it when model flexibility matters more than polish.

Grok Bot arrived in August 2026 as something structurally different: every other harness here runs on your machine, while a Grok Bot gets its own cloud computer. It signs into the tools you use, keeps working while your laptop is shut, and comes back when something needs approval. Show it a workflow once and it saves that workflow as a routine it can run on a schedule.

OpenClaw is built around always on operation, with recurring work as cron jobs and the agent reachable from the chat apps you already use. The overnight and VPS patterns that operator kits teach map onto it directly. It is the harness this site covers most deeply.

Hermes is the widest open harness in the field: many providers, many chat surfaces, browser and local runtimes, and a local proxy that lets other agent clients borrow its providers. Breadth is the point, and also the cost, so it is a better second harness than a first one.

Pi is a deliberately minimal terminal agent: extensions, skills and prompt templates, and not much else on purpose. It reads skills folders directly and runs headless with one flag, so recurring work goes through cron or Task Scheduler rather than a built in scheduler.

Cline started as the VS Code extension many people met agents through, and now ships a CLI with its own cron for agents that run without a terminal open. Open source, any model provider, and the shortest walk for an editor first workflow.

Alibaba's open source terminal agent is tuned for the Qwen models but takes other providers' keys too. It reads skills, has scheduled tasks and runs headless. The Qwen models are among the cheapest that can do this work, which makes it the budget pick.

DeepSeek's harness runs as dsh and arrived in August 2026 as an open source system where everything is a plugin: models, tools, skills, scheduling, even the interface. It runs a local server with a web interface rather than a chat in the terminal. Newest on this list and moving fastest.

Antigravity is Google's agent first development environment: agents plan, run and verify work across the editor, a terminal and a browser, and report back with artifacts a person can review. Its agy command line runs the same agents headless, which is what makes scheduled routines possible on it.