Two cross-harness cost benchmarks, and they disagree

Same model (GPT 5.6 Sol at medium), same environment, same agentic tasks with known-good outcomes, harness versions pinned. API token totals ran from 172,807 for smol to 5,073,137 for Claude Code, a 29.4x spread with the model held constant. Schranz: "Do not underestimate how much popular harnesses are spamming the context window." He builds smol, the winning harness, and discloses it unprompted. The chart also says 30 runs while his comment says "10 agentic tasks, a couple of times," which he never reconciles. A second benchmark, posted by Composio on 31 July in dollars per task at Kimi K3 list prices, inverts three of the six ranks. Hermes is second most expensive on tokens and cheapest on dollars, at $0.39 against Claude Code's $1.47. Both agree Claude Code is dearest by a wide margin. Composio's methodology has not been read here, and Composio sells agent tooling.

Why it matters: Harness overhead is now measurable rather than arguable, and unsettled: two measurements of the same six tools rank them differently depending on whether you count tokens or dollars. Any claim about harness cost has to say which.