Fable, Mythos, Opus 4.8, Sonnet 4.6, Haiku — Anthropic's 2026 lineup is no longer "one model you talk to." It's a fleet you route between. I spent a month inside Claude Code orchestrating all of them across real codebases. Here's which model to reach for, when, and the routing playbook that quietly doubled my throughput.
Why I Went Down This Rabbit Hole (Again)
Last time I wrote about Claude Skills and called Claude Code the killer host for them. Since then, two things happened that changed how I work day to day.
First, the models got genuinely strange-good. In the span of a few months Anthropic shipped Sonnet 4.6, Opus 4.8, and then an entirely new tier above Opus — the Mythos class — released to the public as Claude Fable 5. We went from "the AI suggested a decent diff" to Stripe reporting that Fable 5 ran a codebase-wide migration on a 50-million-line Ruby codebase in a single day — work that would've taken a team over two months by hand.
Second, Claude Code stopped being a single-model tool. With a fleet of models at different price/speed/intelligence points, the highest-leverage skill in 2026 isn't prompting — it's routing. Knowing which model to put on which task is the difference between burning $200 of tokens on a typo fix and one-shotting a multi-service refactor.
