OpenAI autonomously improved GPT-5.6's inference efficiency using GPT-5.6 itself

OpenAI said GPT-5.6 Sol helped optimize the GPT-5.6 inference stack.

The changes targeted GPU kernels, speculative decoding, KV cache handling, and agent harness design.

OpenAI said production serving costs fell 20% and token-generation efficiency rose by more than 15%.

The case shows AI models are increasingly being used to improve their own deployment and performance.