Reason Machines Launches Coding Harness Cutting Task Costs by 22%
Reason Machines released Reason, a coding harness that keeps the prompt prefix byte-identical across turns to trigger OpenAI's prefix-caching discount, cutting repeated-token billing from $10 to $1 per million. It claims better Terminal-Bench and DeepSWE results than leading harnesses at 22% lower cost per task than OpenAI Codex.
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Rohan Paul (@rohanpaul_ai) · 2026-11-13 22
Reason Machines just launched Reason, a coding harness that wraps a single model like GPT-6 Astra and solved tasks 22% cheaper than OpenAI’s Codex.
How: A traditional coding agent resends its context to the model on every step, so Reason trims that load:
Reason holds the prompt prefix identical between turns, by putting its fixed instructions and small tool list at the top of every prompt and only adding new code and results at the end, never rewriting or reshuffling the earlier text.
Since every turn starts with the exact same text, OpenAI recognizes it from the previous turn and bills those repeated tokens 90% cheaper, at $1 instead of $10 per million.
↳ 引用 @xadisingh (Adi Singh): Frontier coding performance at up to 20x lower cost.
Introducing the world’s most cost-efficient harness: Reason
Stop burning thousands on runaway agent bills.
Reason outperforms top harnesses on Terminal-Bench and DeepSWE while dropping cost per task to a fraction of the frontier baseline.
Comment “Reason” and we’ll send you early access + free compute credits.
Try for free:
