Local Open-Weight LLMs in Coding Harnesses

I have been taking different local open-weight LLMs for a test drive in different harnesses (Qwen-Code, Codex, Claude Code).

30B Mixture-of-Experts models are kind of a nice sweet spot and can solve challenging problems. And they get roughly 40 tok/sec on a Mac or DGX Spark, which is similar to GPT 5.5 in a Pro subscription and totally usable for everyday work.

More interesting is also the harness choice! Claude Code seems to be using 2x as many tokens as Codex.

Gemma 4 E2B is here just for reference to show that the tasks can’t be trivially solved by smaller models.

The longer write-up is now available at [Using Local Coding Agents](https://magazine.sebastianraschka.com/p/using-local-coding-agents).

Source: lightly edited website version of my [Substack note](https://substack.com/@rasbt/note/c-283141629).

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