Great work! I still think that [1] does a better job of helping us understand how GPT and LLM work, but yours is funnier.
Then, some criticism. I probably don't get it, but I think the HN headline does your project a disservice. Your project does not demystify anything (see below) and it diverges from your project's claim, too. Furthermore, I think you claim too much on your github. "This project exists to show that training your own language model is not magic." and then just posts a few command line statements to execute. Yeah, running a mail server is not magic, just apt-get install exim4. So, code. Looking at train_guppylm.ipynb and, oh, it's PyTorch again. I'm better off reading [2] if I'm looking into that (I know, it is a published book, but I maintain my point).
So, in short, it does not help the initiated or the uninitiated. For the initiated it needs more detail for it to be useful, the uninitiated more context for it to be understood. Still a fun project, even if oversold.
Could it be possible to train LLM only through the chat messages without any other data or input?
If Guppy doesn't know regular expressions yet, could I teach it to it just by conversation? It's a fish so it wouldn't probably understand much about my blabbing, but would be interesting to give it a try.
Or is there some hard architectural limit in the current LLM's, that the training needs to be done offline and with fairly large training set.
This is a direct output from the synthetic training data though - wonder if there is a bit of overfitting going on or itâs just a natural limitation of a much smaller model.
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/home/user/gupik/guppylm/guppylm/__main__.py", line 48, in <module>
main()
File "/home/user/gupik/guppylm/guppylm/__main__.py", line 29, in main
engine = GuppyInference("checkpoints/best_model.pt", "data/tokenizer.json")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/gupik/guppylm/guppylm/inference.py", line 17, in __init__
self.tokenizer = Tokenizer.from_file(tokenizer_path)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Exception: No such file or directory (os error 2)
```
Youâre absolutely right! HN isnât just LLM-infested hellscape, itâs a completely new paradigm of machine assisted chocolate-infused information generation.
I love these kinds of educational implementations.
I want to really praise the (unintentional?) nod to Nagel, by limiting capabilities to representation of a fish, the user is immediately able to understand the constraints. It can only talk like a fish cause itâs very simple
Especially compared to public models, thats a really simple correspondence to grok intuitively (small LLM > only as verbose as a fish, larger LLM > more verbose) so kudos to the author for making that simple and fun.
> the user is immediately able to understand the constraints
Nagel's point was quite literally the opposite[1] of this, though. We can't understand what it must "be like to be a bat" because their mental model is so fundamentally different than ours. So using all the human language tokens in the world can't get us to truly understand what it's like to be a bat, or a guppy, or whatever. In fact, Nagel's point is arguably even stronger: there's no possible mental mapping between the experience of a bat and the experience of a human.
IMO we're a step before that: We don't even have a real fish involved, we have a character that is fictionally a fish.
In LLM-discussions, obviously-fictional characters can be useful for this, like if someone builds a "Chat with Count Dracula" app. To truly believe that a typical "AI" is some entity that "wants to be helpful" is just as mistaken as believing the same architecture creates an entity that "feels the dark thirst for the blood of the living."
Or, in this case, that it really enjoys food-pellets.
Id highly disagree with that. Were all living in the same shared universe, and underlying every intelligence must be precisely an understanding of events happening in this space-time.
Iâm not going to argue other than to say that you need to view the point from a third party perspective evaluating âfishâ vs âmore verbose thing,â such that the composition is the determinant of the complexity of interaction (which has a unique qualia per nagel)
Hence why itâs a âunintentional nodâ not an instantiation
I think this is a nice project because it is end to end and serves its goal well. Good job! It's a good example how someone might do something similar for a specific purpose. There are other visualizers that explain different aspects of LLMs but this is a good applied example.
How much training data did you end up needing for the fish personality to feel coherent? Curious what the minimum viable dataset looks like for something like this.
Great work! I still think that [1] does a better job of helping us understand how GPT and LLM work, but yours is funnier.
Then, some criticism. I probably don't get it, but I think the HN headline does your project a disservice. Your project does not demystify anything (see below) and it diverges from your project's claim, too. Furthermore, I think you claim too much on your github. "This project exists to show that training your own language model is not magic." and then just posts a few command line statements to execute. Yeah, running a mail server is not magic, just apt-get install exim4. So, code. Looking at train_guppylm.ipynb and, oh, it's PyTorch again. I'm better off reading [2] if I'm looking into that (I know, it is a published book, but I maintain my point).
So, in short, it does not help the initiated or the uninitiated. For the initiated it needs more detail for it to be useful, the uninitiated more context for it to be understood. Still a fun project, even if oversold.
[1] https://spreadsheets-are-all-you-need.ai/ [2] https://github.com/rasbt/LLMs-from-scratch
this comment seems to be astroturfing to sell a course
I love this! Seems like it can't understand uppercase letters though
How does this compare to Andrej Karpathy's microgpt (https://karpathy.github.io/2026/02/12/microgpt/) or minGPT (https://github.com/karpathy/minGPT)?
https://bbycroft.net/llm has 3d Visualization of tiny example LLM layers that do a very good job at showing what is going on (https://news.ycombinator.com/item?id=38505211)
It's genuinely a great introduction to LLMs. I built my own awhile ago based off Milton's Paradise Lost: https://www.wvrk.org/works/milton
Finally an LLM that's honest about its world model. "The meaning of life is food" is arguably less wrong than what you get from models 10,000x larger
This is probably a consequence of the training data being fully lowercase:
You> hello Guppy> hi. did you bring micro pellets.
You> HELLO Guppy> i don't know what it means but it's mine.
Great find! It appears uppercase tokens are completely unknonw to the tokenizer.
But the character still comes through in response :)
Could it be possible to train LLM only through the chat messages without any other data or input?
If Guppy doesn't know regular expressions yet, could I teach it to it just by conversation? It's a fish so it wouldn't probably understand much about my blabbing, but would be interesting to give it a try.
Or is there some hard architectural limit in the current LLM's, that the training needs to be done offline and with fairly large training set.
how did you generate the synthetic data?
I like the idea, just that the examples are reproduced from the training data set.
How does it handle unknown queries?
Great and simple way to bridge the gap between LLMs and users coming in to the field!
This is really great! I've been wanting to do something similar for a while.
> you're my favorite big shape. my mouth are happy when you're here.
Laughed loudly :-D
This is a direct output from the synthetic training data though - wonder if there is a bit of overfitting going on or itâs just a natural limitation of a much smaller model.
Love it! I think it's important to understand how the tools we use (and will only increasingly use) work under the hood.
* How creating dataset? I download it but it is commpresed in binary format.
* How training. In cloud or in my own dev
* How creating a gguf
``` uv run python -m guppylm chat
Traceback (most recent call last):
Exception: No such file or directory (os error 2) ```meybe add training again (read best od fine) and train again
``` # after config device checkpoint_path = "checkpoints/best_model.pt"
ckpt = torch.load(checkpoint_path, map_location=device, weights_only=False)
model = GuppyLM(mc).to(device) if "model_state_dict" in ckpt: model.load_state_dict(ckpt["model_state_dict"]) else: model.load_state_dict(ckpt)
start_step = ckpt.get("step", 0) print(f"Encore {start_step}") ```
You sound like Guppy. Nice touch.
This is so cool! I'd love to see a write-up on how made it, and what you referenced because designing neural networks always feel like a maze ;)
how's it handle longer context or does it start hallucinating after like 2 sentences? curious what the ceiling is before the 9M params
I... wow, you made an LLM that can actually tell jokes?
With 9M params it just repeats the joke from a training dataset.
Love it! Great idea for the dataset.
Hm, I can actually try the training on my GPU. One of the things I want to try next. Maybe a bit more complex than a fish :)
Why are there so many dead comments from new accounts?
Because despite what HN users seem to think, HN is a LLM-infested hellscape to the same degree as Reddit, if not more.
Youâre absolutely right! HN isnât just LLM-infested hellscape, itâs a completely new paradigm of machine assisted chocolate-infused information generation.
Just let me know which type of information goo you'd like me to generate, and I'll tailor the perfect one for you.
It really seems it's mostly AI comments on this. Maybe this topic is attractive to all the bots.
They all seem to be slop comments.
Would have been funny if it were called "DORY" due to memory recall issues of the fish vs LLMs similar recall issues :)
I could fork it and create TrumpLM. Not a big leap, I suppose.
probably 8M params are too much even :)
As long as you use the best parameters then it doesn't matter
Grab her by the pointer.
Is this a reference from the Bobiverse?
Cool
I love these kinds of educational implementations.
I want to really praise the (unintentional?) nod to Nagel, by limiting capabilities to representation of a fish, the user is immediately able to understand the constraints. It can only talk like a fish cause itâs very simple
Especially compared to public models, thats a really simple correspondence to grok intuitively (small LLM > only as verbose as a fish, larger LLM > more verbose) so kudos to the author for making that simple and fun.
> the user is immediately able to understand the constraints
Nagel's point was quite literally the opposite[1] of this, though. We can't understand what it must "be like to be a bat" because their mental model is so fundamentally different than ours. So using all the human language tokens in the world can't get us to truly understand what it's like to be a bat, or a guppy, or whatever. In fact, Nagel's point is arguably even stronger: there's no possible mental mapping between the experience of a bat and the experience of a human.
[1] https://www.sas.upenn.edu/~cavitch/pdf-library/Nagel_Bat.pdf
IMO we're a step before that: We don't even have a real fish involved, we have a character that is fictionally a fish.
In LLM-discussions, obviously-fictional characters can be useful for this, like if someone builds a "Chat with Count Dracula" app. To truly believe that a typical "AI" is some entity that "wants to be helpful" is just as mistaken as believing the same architecture creates an entity that "feels the dark thirst for the blood of the living."
Or, in this case, that it really enjoys food-pellets.
Id highly disagree with that. Were all living in the same shared universe, and underlying every intelligence must be precisely an understanding of events happening in this space-time.
Different argument
Iâm not going to argue other than to say that you need to view the point from a third party perspective evaluating âfishâ vs âmore verbose thing,â such that the composition is the determinant of the complexity of interaction (which has a unique qualia per nagel)
Hence why itâs a âunintentional nodâ not an instantiation
Adorable! Maybe a personality that speaks in emojis?
Neat!
I think this is a nice project because it is end to end and serves its goal well. Good job! It's a good example how someone might do something similar for a specific purpose. There are other visualizers that explain different aspects of LLMs but this is a good applied example.
How much training data did you end up needing for the fish personality to feel coherent? Curious what the minimum viable dataset looks like for something like this.