Coding agent harness, and which parts of it actually change the output
A harness is everything in a coding agent except the model. Two September 2026 studies measured which parts of it matter: context management when the window is tight, planning mostly as a cost saver, and the harness as a whole far more for your bill than for your pass rate.
SESergei GordeichukSenior Software engineer · The master of Stackness











