OpenHands

A lot gets written about agent harnesses, but the interesting ones mostly run behind a closed door. OpenHands is the exception: an agent that writes code, runs commands and works in the browser - with its entire loop out in the open.

What pays off most is looking at the parts that blog posts leave out. How is the history trimmed once the context window fills up? What happens when a tool returns an error - abort, retry, replan? How is the execution environment fenced off so the agent cannot touch the whole system? Those are exactly the questions a homegrown harness fails on, and here the answers exist as code.

You do not have to adopt the agent for that. It is enough to use it as a textbook: one implementation you can hold your own decisions against.