Tutorials, deep dives and product notes — built for developers.
GPT-6.1 Sol replaced GPT-6 Sol after seven days: +4 index points, +12 on Terminal-Bench 4.0, and a cache rate halved to $0.10. It also dropped the "none" reasoning setting, uses 10-30% more output tokens, and is measurably slower.
Sixty days apart: a 29.7-point jump on scientific research, a 200,000-line codebase audit that drops from 20+ hours to under 3, and a 40% cost cut — plus four API changes that will 400 your Opus 5 integration.