OpenAI shipped GPT-5.6 in three flavors (Sol, Terra, Luna) on June 26, 2026 — but only to a small invitee list, pending US government review. Here's the practitioner's read: what the 1.5M context window actually unlocks for marketers, the pricing reality (Terra is the real story, not Sol), and the four workflows I'll route to it the day it opens up.
Anthropic's first public Mythos-class model is fast, opinionated, and 2× the price of Opus 4.8. After a week of running real marketing jobs through it, here's the actual breakdown — capabilities, costs, the 30-day data retention rule that affects agencies, and the marketer use cases where Fable 5 actually wins.
