What is an agent harness?
An agent harness is the software that runs one AI agent: the model loop, the tools, the context and memory, the channels it speaks through. Claude Code and NousResearch’s hermes-agent are harnesses; so is the long tail of open-source agent runtimes. The harness makes an agent capable. What it deliberately does not answer — who authorized the agent, what it may act on, and how its finished work is verified — is the layer above: the execution protocol, and the infrastructure that enforces it live.
The map, not a claim
This page defines a layer FlashyOS deliberately does not operate, so read it as a map rather than a pitch. A harness is the runtime a single agent lives in: it holds the conversation with the model, exposes tools, manages context and memory across sessions, and connects the agent to the surfaces where work arrives — a terminal, a messaging platform, an editor. The best ones are excellent, open-source, and model-agnostic, and there are many: Claude Code, hermes-agent, and kin. Capability competition lives here, and it is fierce, fast, and healthy.
The execution triptych: harness → protocol → infrastructure
The harness makes an agent capable. The agent execution protocol makes its work governed — who authorized it, its jurisdiction, its escalation thresholds, and how completed work seals into a verifiable record. Agent execution infrastructure is the running system that enforces those answers live, task by task. Three layers, three different products, and the seam between them is deliberate: the AAO manifest names roles, never software, so any harness can staff a role. An organization that swaps a role’s harness changes nothing in its charter — roles outlive the software that staffs them, the way offices outlive office-holders.
Why FlashyOS builds no harness
A platform that ships its own harness competes with every harness its tenants prefer, and turns a coordination layer into a tool with a lock-in problem. Harness-agnostic is doctrine here: we never build the agent — we make agents employable. The division of vocabulary follows the division of labor: skills standards such as agentskills.io describe what an agent can do; the AAO manifest governs what it is authorized to do, and who answers for it. An agent carries both, and neither standard has to lose for the other to win.