GPT-5.6 ships globally after Commerce cleared it, lifting the same restrictions once placed on Mythos and Fable. The early verdict was capable but outmatched: if a single Fable turn does the work of ten from Sol, the turn itself is the unit being renegotiated.
A developer released a Self-Improvement Loops skill for meta-harnesses that rewrite their own scaffolding, warning that the loop will optimize whatever signal you give it.