HarnessTax: How Much Does the Harness Matter for Coding Agents?

What happened

What does a coding-agent harness actually add, and at what cost? It turns out your Claude models may not need Claude Code… We evaluate 21 model–harness pairs spanning seven models and three harnesses—Claude Code, Codex CLI, and Pi—on SWE-bench Lite and Terminal-Bench 2.0.

Summary assembled by rule from the sources below

Timeline

1. 22:10
   First appeared on Hacker NewsHHacker News
2. 14:45
   Discussion started on LobstersLLobsters

Sources