# fable

Anthropic engineer trq212 shares his methodology for coding with Claude Fable 5: the bottleneck isn't model capability anymore—it's whether users can surface their 'unknowns' before, during, and after implementation. Includes prompt examples plus HTML artifacts for visualizing blind spots and plans.

Fable 5 nails on the first try what used to take days — but it's too proactive and over-elaborates, so prompts tuned for Opus 4.8 hold it back. The official guide isn't about making it stronger; it's about reining it in: steer with intent, draw boundaries, talk like a human when the run ends.

Simon Willison gave Fable 5 a screenshot and one line: fix a stray scrollbar. Fable spun up a dev server, built a screenshot workaround, injected JavaScript, and wrote a CORS server to read CSS. Two CSS lines, $12, and an unsandboxed-agent warning.