OpenAI, Thrive, and Crete Build Self-Improving Tax Agents With Codex — 97% Accuracy on 7,000 Returns

OpenAI Blog·high signal

OpenAI published a case study on May 27 detailing how Thrive Holdings and Crete Professional Alliance (30+ accounting firms) built a self-improving tax agent using Codex. The system processed 7,000 1040/1041 returns at 97% accuracy, saving practitioners a third of their time and boosting throughput ~50%. The defining feature is a Codex-driven feedback loop: every human correction triggers targeted evaluations and code modifications, so the system continuously improves from practitioner corrections.