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Astra can read and write weights to improve Qwen

931 points • by dbreunig • today at 6:21 PM • 298 comments • view on HN

Comments

vessenes • today at 7:00 PM

This is insane.

Astra can, without tooling, determine what games small networks are trained on, can edit the weights of networks directly to improve outcomes, and can hand edit a small qwen model to improve its math skills by like 5x.

I'm shook. If you'd asked me this morning whether LLMs have native understanding of their weights that is less than human <-> neuron understanding, the same as human or more than human, I would have said "same to less" depending on definitions.

No human can go edit a brain to become better at math. This is just very, very surprising to me and extremely interesting. I would guess this upsets quite a number of interp theories and philosophical takes on what's going on with these networks.

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xg15 • today at 8:51 PM

And here we go...

As others have said, while still absolutely insane, I don't find it completely out-of-the-blue surprising. One of the recurring abilities of (current-generation) LLMs seem to be to rapidly grasp very complex systems, where humans would need months or years to reach the same level of expertise.

You can see this in the way a coding agent can "understand" and explain sprawling legacy codebases in seconds.

You can also see it in the projects that are using them to reverse-engineer proprietary IoT protocols or computer games.

But those were all systems where we had detailed knowledge about what structures are there to be reverse-enginered.

If the models can transfer this ability to some other systems where we don't know the underlying structure then I think we will be in for a lot more craziness in the future. (Protein interaction networks? DNA sequences? Animal languages?)

As for weights, if the models really can analyze the semantics behind specific weights or directions, I have my hopes that they could also give a textual explanation or help designing tools to make "handcrafting" weights more practical in general.

NitpickLawyer • today at 7:20 PM

> As a result, Astra spots and fixes a common failure of tiny reasoning models: they loop [13]. When the base model loops, it repeats the same text and rarely reaches an answer (85 of its first 96 practice answers ran to the 32,768-token limit). Astra traced the looping to one direction written by the MLPs of layers 15 and 19, and subtracted that direction from 64 output columns in each (131,072 weights), much like removing a behavior by deleting a single direction from a model’s weights

HA! Now that's cool. Not necessarily the improvements, those are ancient and probably overtrained benchmarks, but it's so cool that the model found a singular direction for this "loop bug". I imagine it could possibly do much the same thing in finding other "single directions" on a variety of topics (if allowed by guardrails). This is really really cool, especially for the mechinterp folks.

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vanyle • today at 7:50 PM

I don't think this is an emergent capability. I think Astra was trained on neural weights data as an attempt by OpenAI to get to recursive self improvement.

Something similar happen in early GPT models which had a lot of chess game in standard notation in their training data which made them very good at chess as long as your prompt had the right format.

We'll see if this attempt at RSI worked.

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itkovian_ • today at 8:40 PM

This was shocking to me; but on reading it makes far more sense.

- the primary experiments are on small policy networks - they are compressed dynamic system models. The observation and action space can be read off. It’s not surprising to me that these types of networks can be used to identify the env they were trained on

- the exps on actual llms remove looping behaviour and that’s it - from article “but it could not add an ability the model lacked”

I’d say this is fortunate because if llms could do the latter, rsi would be immediate. It may be possible we simply need bigger and better edit models, but at least from the experiments there doesn’t seem to be any indication that is imminently about to work.

Conceptually incredibly interesting non the less.

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futureshock • today at 7:16 PM

I find this just completely shocking. I’m definitely skeptical. It just doesn’t line up with my understanding of how these models work. Is there really enough training data on direct weight editing to give a model this skill? Maybe it’s evidence that OpenAI has been creating a lot of training data on ML research. I’m surprised that was put into a public facing model though.

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Imnimo • today at 7:16 PM

On balance I'm not that surprised that it can guess games by looking at the weights of a tiny neural net. A human can do the same by looking at the weights of an MLP trained on mnist, for example. With that simple structure, it's easy to look at the input layer and see that features correspond to the spatial location of objects of interest.

I'm much more surprised that it can do this on larger models, although the details seem to suggest that it's given a lot more freedom to run forward passes and do limited experiments, not just eyeball the weights.

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Shihan • today at 8:50 PM

Why does this give me Skynet feelings? "Skynet begins to learn at a geometric rate. It becomes self-aware at 2:14 a.m. Eastern time, August 29th. In a panic, they try to pull the plug."

Roland303 • today at 7:39 PM

I dont feel the air of impressivness here. It seems like of course so. Of course theres geometric relationships in the data we dont understand, of course a mathimatical relationship machine found it.

These models are made by a vanishingly small group of people based on how much a frontier lab consumes, of course theres increasing capability in these areas, arent these models having access to much of the same data? didnt chat gpt 4 try to do something like this to chat gpt 2? havent surgical weight edits been done before?

What is with this level of astonishment here? Astraturfing? Im not THAT impressed, i applaude the teams progress, but im not in wonderment.

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nsypteras • today at 8:20 PM

I do wonder if the labs have already started including weight updates in their training sets as a means of teaching RSI via RL and this is basically just discovering that. Regardless if this ability is emergent or achieved through finetuning though, it's pretty incredible.

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jdoliner • today at 8:47 PM

This plus the interpretability result from a few weeks ago have completely upended my understanding of what model weights are.

alex_suzuki • today at 8:30 PM

> "You get used to it. I don't even see the weights. All I see now is blonde, brunette, redhead."

IYKYK

AlexErrant • today at 8:15 PM

As insane as this result is, next steps are even crazier:

> We are currently building a benchmark and a harness for LLMs’ capability on Weight-Space Programming. We believe this will provide a standardized evaluation to measure and accelerate progress in Weight-Space Programming, turning what currently seems like black magic into a rigorous, reproducible engineering discipline.

Imagine this benchmark lasting as long as Arc-AGI-3 has. This could be the first foothold on hill-climbing mech-interp.

swazzy • today at 8:43 PM

> This is simultaneously very cool but also a bit exaggerated. Reading the prompt you gave, the prompt veeery much hints that looping is the issue and to find neurons that fix this. And as you say (screenshot below), it couldn't otherwise improve math.

https://x.com/giffmana/status/2117346161866514524

FeepingCreature • today at 7:28 PM

I suspect a lot of this is not (just) capability but bravery. A human would be daunted by even a small neural net; the task would seem too challenging to be worth attempting. Astra, fearless, just assumes an answer exists and then tries to reverse and execute on it.

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woggy • today at 8:45 PM

OK, so is this how LLMs will be able to learn?

Just had a thought: two local models, one with static weights trained mostly in the space of manipulating neural network weights, manipulating the weights of a dynamic LLM to enable learning.

davesque • today at 7:14 PM

Couldn't this just be a result of Astra training on massive amounts of circuit theory or mechanistic interpretability literature or other related topics? In other words, not black magic?

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lifty • today at 7:00 PM

Keep in mind that labs are now training their models for RSI so most likely the same training is useful for improving open source models, as long as guard rails are lax enough :) which most likely won’t last long.

dumberquestions • today at 7:31 PM

We don't know the specifics of what type of ML related training Astra underwent, and it wouldn't be crazy to find out that small model experiments are a big part of model training.

What's surprising though is that I'd expect this type of training to be exclusive to internal model snapshots or at least heavily guardrailed against in public models.

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draxen • today at 8:46 PM

>Qwen3.5-0.8B

I wonder what the biggest dense model in the same model family, the surprisingly capable Qwen3.5-27B, would be able to do if given the same task.

mynti • today at 7:04 PM

I feel like 'create a network to play an atari game' is not very hard for a frontier model. Since it has seen plenty of those on its training. If it could create a network for a problem that is niche just by tweaking numbers, that would be a lot more surprising. Making qwen better at math to me was a lot more surprising

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alienbaby • today at 7:36 PM

This has to be a good step to recursive self improvement, no? Give a model it's own weights and tell it to make them better at x,y,z, etc...

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evanjrowley • today at 8:27 PM

Seeing that they were working on Qwen3.5-0.8B has given me new hope. I would really like to get Jeff-Code working the way it was advertised, but so far, all of my results with Jeff-Code have shown it to underperform compared to direct Qwen3.8-27B. It's possible there is something wrong with the underlying Jeff v1.3 model, which is based on the same Qwen3.5-0.5B. Perhaps Astra will solve my problem.

[1] https://github.com/firelex/jeff-code

[2] https://github.com/firelex/jeff#benchmarks

faxmeyourcode • today at 8:22 PM

This is so cool. It feels similar to the models' ability to read base64.

https://www.lesswrong.com/posts/5F6ncBfjh2Bxnm6CJ/base64benc...

btucker • today at 8:12 PM

This survey paper from earlier this year has a lot of good related work:

A Survey of Weight Space Learning: Understanding, Representation, and Generation

https://arxiv.org/pdf/2603.10090 https://github.com/Zehong-Wang/Awesome-Weight-Space-Learning

Aboutplants • today at 8:36 PM

I just want to say, absolutely incredible work by the authors! And the presentation is also very well done. Kudos and congratulations!

crorella • today at 8:24 PM

This is remarkable and something I would have never though of doing regardless of how much it makes sense!

I think we are pre-conditioned (at least this generation) to put artificial blocks to what the AI can achieve, I think new generations won't have this issue.

rpcope1 • today at 7:04 PM

So wait so this considered "distillation" and how long until we get another public letter from Dario or Sam pants shitting over this?

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bluejay2387 • today at 8:22 PM

This might be one of the most surprising things I have seen in AI. It's like we taught someone to make vases by reading an enormous library of "How to make a vase" books and somehow that person intuited material science.

lisenKaci • today at 7:35 PM

Does this mean they can improve their own weights through some system, or can they only do this for much smaller models?

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neuronexmachina • today at 7:58 PM

I appreciate the post included the reasoning traces they had available, but it's too bad the first part of it is internal/hidden to Astra. The first bit of that process is what I'm most curious about:

> [Before writing this, Astra thought for 1,034 tokens. That thinking is hidden. The API returns only its 5 headings: Reconstructing the active map / Mapping maze corridors / Preparing exact maze map / Reconstructing row groupings / Checking channel patterns]

mlsu • today at 7:15 PM

I wonder if this has to do with the aggressive RL that these models are undergoing. I'm basically a layman but it seems to me that:

- models are trained to improve on some task, e.g. 'improve at math puzzles' is commonly used.

- the best way to improve on some task is to have interpretability into your own neurons (..?)

- if your interpretability is good, you can improve faster - if you have insight into how your own neurons work and can improve them directly

- therefore, models naturally put effort into 'self-interpretability'

I wonder if this is part of the 'secret sauce' of what the labs are doing: giving models the ability to interpret their own weights in the RL loop. In my mind, this is the only explanation for how they could succeed at a task like this. How many blog posts are on the open internet that say "this is each weight of a neural network and what each one means"?

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alienbaby • today at 8:17 PM

I guess then it has no problem working in high dimensional spaces, why would it have?. I wonder if perhaps it's pulling on a bunch of those dimensional threads and getting the outcome it's after, while subtly altering the outcomes across many thousands more dimensions in unnoticed ways. This feels more like an us problem, as in, we think in 4D (just to pick something) and we imagine and theorise in 4d, and propose questions in 4d, whereas a model has no such barriers, and can think in many more D's than we can.

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m1coti • today at 7:49 PM

I am still reading through this and will probably try to comprehend it a bit more. Some of it really seems to follow Arditi et al. (2024) (https://arxiv.org/abs/2406.11717). Projecting out a direction can only remove behaviour and not add capability so the jump mostly comes from unblocking the looping.

rumblefrog • today at 7:26 PM

I wonder if the same technique can be applied to model abliteration? It would easily make any open weight models uncensored.

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famouswaffles • today at 6:59 PM

This is pretty massive, and a result I (and I think most?) would have never expected. Holy Shit. How?? Did OpenAI figure out a way to train this? Are they even aware?

daemonritus • today at 8:18 PM

almost all the networks given to astra here are trained on relatively simple single tasks whose geometric/algorithmic structure could be expected to become embedded in surface level weight space geometry, and for a harder task ("which network is sycophantic") where there's less obvious structure to exploit, the method fails. cool but maybe not as paradigm shifting as the authors suggest

ernubufiei • today at 7:03 PM

I wonder if this is a result of internal training/RL of Astra for RSI, and this particular use-case not being caught by guardrails.

Absolutely incredible regardless.

levinb • today at 7:28 PM

Just logging in here for the record to state that this property of neural networks is one of the most important aspects of their operation. The convergence of this sort of interoperability, tune-ability, and modularity is probably the most important final frontier in all of ML/AI/software.

Kudos to this fellow for having the temerity, or perhaps even naivete, to discuss it publicly. All my work is private, as I am sure it is inside the big labs.

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gunalx • today at 7:04 PM

How out of trivial domain info does this go. Can we use this for general time series, image generation, speech synthesis as well, or dies it cap at small model sizes and common domains?

bfung • today at 7:15 PM

Same initial reaction as everyone else, but also some follow up questions (just asking, not expecting any answer):

* Does this work on similarly powerful models as-is, or it needs more input. Ex: Astra editing Astra - presumably, Qwen is a “subset” of Astra weights, but what happens on “non-subset”s?

* what, if any, is that extra magic sauce?

* does Astra-editing-Astra just make the outputs unstable, as it may know its own weights, but doesn’t know what’s beyond.

enestaylan • today at 7:20 PM

Very interesting. I wonder if it’s because its dataset contains the weights of a gazillion different models. Maybe most neural networks trained on similar data eventually converge to isomorphic spaces anyway, even if the spaces themselves aren’t exactly the same. Or maybe Astra itself was trained with RL for alignment. Or for RSI.

sligbad • today at 7:44 PM

1) I couldn't see it, is there any indication of if the qwen math improvement caused degradations elsewhere?

2) the negative result on making similar improvements in Gemma 3 270M is also fascinating.

Such an unexpected result...

bilsbie • today at 8:05 PM

The obvious question, could models start editing their own weights directly? I call it the Johnny five approach.

olirex99 • today at 7:57 PM

I am not sure on the experiments. For example let’s imagine that Astra is asked to improve the performance of a network.

At first Astra will look at the weights, and try to understand the model behavior. Then if asked he will start to optimize the weights. Now my question is: how can we be sure that inside the thinking process Astra is not hiding a gradiant descending computation?

bilsbie • today at 8:03 PM

GOOD Point by my wife. Why would LLM’s have any understanding of weights? It wouldn’t be in their training data.

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Aboutplants • today at 8:27 PM

Throw out whatever timeline you previously had

isomorphic_duck • today at 8:32 PM

I don’t think this warrants too much surprise — in fact I am a bit surprised by the color of the reactions here. The tasks are standard, on small models and use weight-space reasoning based on very well-known Mech Interp literature. It’s been understood in Mech Interp research circles for some time that results on toy models on algorithmic tasks do not generalise. The weight space geometry that Astra exploits here is pretty standard and one feels like the authors here are being a bit dishonest with their framing to get people not into mech interp literature excited.

KeplerBoy • today at 7:25 PM

Is it aware of projects like [1] and implementing those?

[1] https://github.com/lyramakesmusic/neuron-explorer

jonplackett • today at 8:08 PM

Is there any chance they’ve just seen these weights before and are recognising them?

If not this is mind blowing.

However it would be interesting to k ow if it can understand its own weights, not just weights much simpler than itself.

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