Every coding agent says it is efficient. Almost none of them publish the bill. So we ran the boring experiment: the same bugfix, the same model, the same API, the same prices, and a byte identical prompt, once through opencode and once through the coding agent inside Locally Uncensored.
Headline: opencode averaged 2157 credits over three runs. Our 2.6.6 agent finished the identical task for 1298. That is about 40 percent less, and even the cheapest opencode run came in 29 percent above our number.
The interesting part is not the headline. It is why the gap exists, and it is not the reason most people guess.
Setup
A cost comparison is only worth reading if everything that drives cost is nailed down. What was held constant:
