A preregistered measurement of a Jev-style interface on frozen Qwen3-4B: read the option letter's logits instead of generating grammar-constrained JSON.
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mini-Jev: what a Jev-style typed-decision interface looks like on a frozen Qwen3-4B — read the option letter's logits instead of generating JSON. Preregistered experiment, results, teaching bench.
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What a Jev-style interface looks like on a frozen model: classify against a schema that arrives with the request by reading next-token logits, not by generating JSON. Measured on Qwen3-4B. TypeSafe's Jev is trained for typed decisions without open generation. mini-Jev asks how much of that interface an ordinary frozen model already provides, and measures it against today's path, grammar-constrained JSON.
Quoted from the project's README. Read the full README.
Watch out
MIT. This does not call TypeSafe. Strings and numbers are still generated. On out-of-scope texts, JSON picked none-of-the-above on 47 of 50 and letters on 41 of 50. Runs are Qwen3-4B-Instruct-2507, bf16, greedy.
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Hacker News: mini-Jev reads option-letter logits on a frozen Qwen3-4B instead of generating JSON.
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