Claude Code tip: if a task turns out harder than you expected, type ultrathink while Claude is working. It raises the effort for the rest of that turn. In the terminal on the latest release.
ultrathink is back in the CC CLI.
We turned this off for a while because it's weird and maybe confusing.
But I like weird, and I don't think it's that confusing.
I mostly run Opus 5.5 on medium. Some turns, though, I want to put a little extra mustard on it. ultrathink!