Comment by virtualritz

My verdict after last night trying what was suggested here:

yes, with CLAUDE_CODE_EFFORT_LEVEL=max (or at least high, for this you don't need to set an env var, it will remember) and CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING=1 you can get Claude to perform as before.

I have been using Claude on /effort high since Opus 4.6 rolled out as medium would never get me good enough results (Rust, computer-graphics-related code).

I, too, noticed the drop in quality a month or so ago. With CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING=1 it's back to what feels to be pre-March performance -- but then your tokens will 'evaporate' 40% faster.

And that was not the case then; I had similar/same performance before but wasn't running out of tokens ever on a Max subscription.

So a it's a rug-pull, as before/last late summer, from whatever angle you look at it.