On my end, Opus 5 is Haiku level vs. Opus 4.8 (good) and Fable (superb).

Gets confused by permission prompts, cannot debug a failing test it caused (Opus 4.8 got it right after, without tens of rounds "thinking").

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reilly3000 2 hours ago | parent [-]

Are you using Claude Code/CoWork or an API client? I’m curious if it has different training that makes it more effective with specific instructions/ tool calling methods that are only implemented in official harnesses.

	▲	pixelesque 2 hours ago \| parent [-]
		I'm curious about this too, and it's difficult to get any information about this given everyone has different setups, workflows and use-cases. I bizarrely had Opus 4.8 this week (in pi.dev within a podman container, using openrouter) start installing various python packages (and uv!) within the environment (not as root) when I asked it to code review some fairly basic Rust .rs files that were generally stand-alone (it did very nicely work out and write some stubs for them to build them and work out how they worked). It only gave up with the weird Python installing stuff when it discovered one of the Python packages needed Tensorflow. It seems pretty focused and persistent in continuing its initial approach, and I'm wondering if I need to alter some instructions / initial prompts to rein it in a bit...