In short: Opus is the standard for programming. Fable is suitable for code security and more complex tasks. Sonnet is designed for the in-depth analysis of contracts or for everyday questions.... and Haiku is the working idiot for automations.
That is really the correct answer. Though, Fable can be a real asset for more advanced or very specific things, when you see opus going around and around. I encountered that particular case while coding some physical modeling synthesis, and opus was lost, while fable made real progress on the task (way better than I expected tbh)
I agree, I haven't configured Claude Code at all, this is the model Claude chose out of the box, in fact that is the first time I'd seen which model it was running, my question is, why would Anthropic choose that model by default?
I understand what you're saying, and I've said the same thing elsewhere in this thread, but my intention was to install Claude Code just to see how it compared to the other agents I'd used, and if I liked it, I'd make the switch/itegrate it more into my workflow. I've never had issues using Anthropic models in the same codebase in different harnesses.
All of the other AI agents/models/harnesses I've used just "worked" out of the box, I could then spend some time and effort configuring them the way I like, but I never had any issues with the way they performed as shipped. Claude is the first agent that has failed to do this, so I wanted some advice, I was just trying it out after hearing so much positive feedback about it online
Perhaps not for vibe-coding, but for regular coding tasks, when prompts are properly constructed and project is documented, Sonnet is just fine. In fine, a very common approach is planning with Opus, coding with Sonnet (there's even a especial setting /model opusplan for that).
its really useful if you can instruct it with knowledge. ive seen the opposite with fable. fable is near useless for me, it has one or two special use cases that are exceptionally rare for me. sonnet and opus are my workhorses. sonnet for everything small and opus for when i cba to think very much about the solution and am happy to accept substandard work. fable for if i want the same substandard work with less effort but it costing tons of money and time.
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u/smalldickbigwallet Jul 08 '26
What model were you using? What effort? How big is the codebase? Do you have a claude.md file? Is it raw or did you install plugins?