On Monday I picked Fable 5.2 in Claude Code and went straight back to Opus 5.5. This evening I made it the default and typed one sentence: using three.js, build a fly-by over Mount Fuji. What came back is a 200-second flight round the real mountain, in over Lake Kawaguchi, past the Hōei crater, a slow orbit of the summit and out across Lake Motosu. You can fly it yourself; it’s about a 4 MB download.

The lazy answer to that sentence is a grey cone on a flat plane, and nothing in it asked for more. Fable went and found open elevation data anyway, and when that couldn’t place the lakes it took their outlines from OpenStreetMap. Then it rendered its own frames and fixed what it didn’t like in them: a grid pattern in the grass, a camera that kept missing the lake. I asked for one change to the flight itself, bigger captions.

It’s a small thing next to Saltline, the shooter an Anthropic engineer shared on launch day, built from one prompt in eight hours unattended at an estimated $550. It isn’t a photograph either. Forest and snow are generated from height and slope, so there are no towns or roads, and the phone version is untested on a real phone.

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