Comment by SwellJoe

Pi can only log what the model shows it. Many models keep their thinking traces hidden and only provide a hash or something to recover it on subsequent resumes. DeepSeek shows CoT traces, and is maybe the best model that does so, I think? Kimi stopped providing CoT traces a little while ago in their subscription service via Kimi Code, I believe. I haven't checked GLM or Qwen 3.8 Max, though I guess if you're hosting the open models yourself or using an alternative inference provider there's probably got to be some way to get at that data.

Anyway, this particular harness isn't doing anything unique, but the combination of an official agent intentionally keeping the data and making it accessible to the user and a model API that provides all the information is unusual and worth calling out. It used to be common, most APIs and models and agents showed the reasoning, or could be configured to do so. Most no longer offer it.