Caveman, the install that shortens what Claude writes back, took one of my tasks from 1180 tokens to 159, which is about 87 percent, and that number is real. I want to be careful with it, though, because that was my best result. Other tasks came back only 41 percent and 30 percent smaller. So the honest range from my own runs is 30 to 87 percent depending on the task, and the only way to know yours is to test it on something you repeat. Keep in mind that output is a smaller share of your bill than input. Even a large percentage off the smaller slice saves less in absolute terms than trimming what goes in, which is why rtk, the install that works on the input side, is the bigger win of the two. Try it today: pick one task you run often, note the token count of the reply, install caveman, run the same task again and compare the two. Which task do you run in Claude Code most days, and do its replies tend to be long enough that shortening them would matter?