Definition
Plain language
A minimal open-source software-engineering agent harness used as a comparison baseline.
As stated in the literature
A small ReAct-style coding agent with a three-tool shell interface; used as one of the diverse training and evaluation harnesses in Orchard's cross-harness generalization experiments.
Why it matters: A small, transparent harness makes it easy to test whether training gains come from the recipe or from a heavyweight scaffold.
For example, the agent might use its three shell tools to read a file, run pytest, and apply a patch to fix a failing test.
Heard on the show
“… under two different harnesses — OpenHands, which is a feature-rich multi-agent platform, and mini-swe-agent, which is a tiny three-tool shell harness. …”Episode 047 — When Agent Benchmarks Lie: The Harness Problem in Open-Source AI