What exactly did GPT-6 Astra do in this experiment?

It wrote code to inspect the target model's weights and internal activations, formed hypotheses about behavior, then modified weights and checked the results, according to the author's account.

How much of the model was changed?

The author says about 0.486% of the model's weights were changed, and only one weight tensor, mlp.down_proj.weight in the 20th block, was modified.

Can I try the edited model?

Yes, the author says the model created in this experiment is available on Hugging Face.

Large Language ModelsOpen-Source AIZenn AI/ML1d agoNov 7, 2026, 19:01 JST

GPT-6 Astra edits Qwen3.5-0.8B weights to add zundamon endings

Send on LINE

3 Key Points

What happened
Using Codex with GPT-6 Astra, the author autonomously edited Qwen3.5-0.8B's weights, hitting the zundamon-style ending on 77 of 100 questions and 36 of 50 new ones, changing about 0.486% of weights.
Why it matters
The author says the result came from weight editing rather than prompting or fine-tuning, and that the whole process could be left to an AI.

Not sure about something? Ask the AI

Questions and answers are published on this page.

Summaries like this, every morning.

Get these free every morning

FAQ

What exactly did GPT-6 Astra do in this experiment?: It wrote code to inspect the target model's weights and internal activations, formed hypotheses about behavior, then modified weights and checked the results, according to the author's account.
How much of the model was changed?: The author says about 0.486% of the model's weights were changed, and only one weight tensor, mlp.down_proj.weight in the 20th block, was modified.
Can I try the edited model?: Yes, the author says the model created in this experiment is available on Hugging Face.

Zenn AI/MLRead Original Article

Send on LINE

AI news that matters for your work, delivered every morning.

Pick your industry and the AI tools you use, and get news related to your work every day.

Get it free

Free · 30 seconds with Google · unsubscribe anytimeWhat is AIToday? →

Ask AI

Ask AI anything about this article. The AI reads this article, earlier AIToday articles, and Wikipedia, and cites its sources. Q&As are published on this page for other readers too.