Anthropic's most powerful (and most expensive) model just landed. For a limited time, Kombai is the cheapest place to run it.
Anthropic just released Claude Fable 5, the first generally available model in its new Mythos-class tier — a tier that squarely sits above Opus. Within hours of launch, the consensus from early-access testers was that this is the best coding model in the world, and its benchmark scores tell the same story.
It's available in Kombai today, and for a limited time, we're offering it at 50% off.
Here's what we know so far, what we're still figuring out, and why we want you to try it.
The Most Powerful Model Available Today
Anthropic first built this capability class as Claude Mythos Preview in April, restricted to a small group of cyber defenders and critical infrastructure teams because it had crossed thresholds they wanted to roll out carefully. Fable 5 is the public version: the same underlying model, but with safeguards around a narrow set of high-risk domains.
The benchmarks back up the hype:
It also ships with a 1M-token context window, and it's built to run long: planning across stages, testing its own output, and fixing its own mistakes.
Early Signs: It's Strong at Frontend Work
Although public showcases skew toward backend-heavy dev tasks, the early signals for UI and frontend tasks are just as promising. Anthropic demoed Fable 5 rebuilding a web app's source code from screenshots alone, and the first wave of testers on X have been posting frontend builds that genuinely surprised them.
In our early internal testing, Fable looks like the best-performing model for design and frontend tasks. We’re currently running detailed tests on real design and code tasks of different complexities, and we'll publish a deep dive soon.
It's Very, Very Expensive
Fable 5 costs $10 per million input tokens and $50 per million output — the most expensive model on the market. It routinely burns 500K to 1M tokens on a single task.
That creates a real, shared problem: nobody fully knows yet which tasks justify this model’s cost and which don't. The whole industry is on day one of figuring out where Fable 5 is worth its price — and at these rates, experimenting freely is genuinely painful.
So We're Cutting the Price in Half
For a limited period, Fable 5 is available in Kombai at 50% off — $5 per million input tokens, $25 per million output. That's Opus 4.8 prices for the most capable model on the planet, and right now, Kombai is the cheapest place to run it.
We're doing this because we genuinely want you to try it — not on the easy stuff, where you won't see the difference, but on the hard tasks. That's where this model shows what tier it's in, and your experiments will teach all of us where it earns its price.
It's in your model selector now. Throw something hard at it, and tell us what you find. We'll be folding what we learn (ours and yours) into the upcoming deep dive.
Happy building.
Please Note: Fable 5 carries 30-day data retention on Anthropic's side, and zero data retention (ZDR) isn't supported. If your org is strict on that, Opus 4.8 and Sonnet 4.6 remain fully available in Kombai. Details are in Anthropic's policy.
