Chasing Fable | Blog<br>Table of contents<br>Chasing FableThe magical giftThe questThrough the dark forestThe curse of tonguesUncle Sam’s revengeThe real fable

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Jun 23, 2026<br>Chasing Fable

Patrick Burris<br>Product Engineer

Table of contentsChasing FableThe magical giftThe questThrough the dark forestThe curse of tonguesUncle Sam’s revengeThe real fable

li]:marker:font-medium [&_table]:w-full [&_th]:border [&_th]:border-border-subtle [&_th]:px-12 [&_th]:py-10 [&_th]:text-body-regular [&_th]:font-medium [&_th]:text-content-primary [&_th]:text-left [&_td]:border [&_td]:border-border-subtle [&_td]:px-12 [&_td]:py-10 [&_td]:text-body-regular [&_td]:text-content-secondary [&_td]:text-left [&_pre]:bg-bg-secondary [&_pre]:border [&_pre]:border-border-subtle [&_pre]:rounded-md [&_pre]:p-16 [&_pre]:overflow-x-auto [&_code]:font-mono [&_code]:text-body-regular [&_.payload-richtext>*]:mb-[2.4rem] [&_.lexical-table-container]:overflow-x-auto [&_.lexical-table-container]:rounded-md [&_.lexical-table-container]:border [&_.lexical-table-container]:border-border-subtle [&_thead]:bg-bg-secondary [&_th]:!border [&_th]:!border-border-subtle [&_th]:!px-12 [&_th]:!py-10 [&_th_p]:!text-body-regular [&_th_p]:!font-medium [&_td]:!border [&_td]:!border-border-subtle [&_td]:!px-12 [&_td]:!py-10 [&_td]:font-normal [&_td_p]:!text-body-regular [&_td_p]:!font-normal">Chasing Fable<br>A true story about an AI model that lived 72 hours, and the router I built going after it.

A long, long time ago, about 2 weeks to be precise, in a land called San Francisco there was an AI company named Anthropic. This company had some of the best AI models out on the market and absolutely no one was expecting them to release a new one.<br>So, who even cares about a new model from them? Well, we at Adapt do. Adapt is a place where you can plug all your tools in and it will help you search, work, write code all just by talking to it. We have a very natural-language centric philosophy and as such use the best models available. So that means if a new top-dog comes out, you bet we are going to get it integrated into our platform.

The magical gift

Well, what would you know, Anthropic dropped Fable 5 like it was an anvil in one of those old cartoons. I swear I even saw the anvil shaped hole it left in the ground. The aftermath was pure amazement. I took to my code editor, switched to Fable and wrote the following epic prompt: “Make me Minecraft.” Oh yeah, you know it. I watched on for almost 20 minutes while Claude Code went to town elucidating, simmering and all manner of other gerunds.<br>Just after the 20 minute mark it stopped and asked me if it could run cargo, Rust’s build system - “oh sweet, it wrote it in Rust!” I thought, and wasn’t expecting much. What I loaded was a full voxel engine written in under 30 minutes that ran around 60 FPS, not bad! In fact it was amazing, and we had to get this into Adapt.

The quest

The next morning I came in to work and was talking with my CTO, Sean. We really wanted to see Fable added to Adapt, but the big catch was that it was twice the cost of the next best model. He gave me a great idea - let’s build an intelligence router. We knew that not every task that Adapt does needs Fable, and due to the cost increase we couldn’t justify using it as the main chat model.<br>I was tasked with building a system that would allow Adapt to choose its own intelligence level, an adaptive intelligence system. Like Arthur, I was on a quest for the holy voxel engine, and along the journey I was challenged by several foes - refactoring existing code, incompatible chat histories and finally the U.S. government.

Through the dark forest

I arrived on the outskirts of our codebase early in the morning. It was misty and a little bit chilly, when all of a sudden a bearded man appeared. A wizard? Nay, for it was the existing code that chose our main chat model, sure it was a little grey, but its magic had faded. I slew the wizard, I mean code, and replaced it with a system that allowed me to selectively decide between 3 models, 3 speeds, like the hydra of Lerna. Now you would think that the hero is supposed to help the wizard and slay the hydra, but this isn’t that kind of story. Our beast has 3 heads - Fast, Balanced and Deep. Deep mode was Fable 5 and my ticket back to voxel-land. With this task completed I delved deeper into the woods.<br>I had to make this system usable and my task was to make sure that the Adapt agent could actually set its intelligence level. From an old forge I found, I crafted a mighty tool, one that would let our system adapt to any circumstance. With the rod of intelligence the mighty lord of refactoring was quelled. Each chat on our platform has an intelligence level that can be changed by Adapt invoking the tool. It can do this mid-turn meaning that in the middle of a long task it can switch to Fast to crawl websites,...