1. Introduction
The smallest My Little Pony language model we could find: 32 million parameters and 64 MB of weights. This is the pretrained base checkpoint: a plain next-token model, not a chat assistant.
- Trained from scratch. No distilled weights and no borrowed backbone: a Llama architecture with a 16,384-token vocabulary, pretrained on a fandom corpus.
- A foundation, not a product. It has no dialogue format and no instruction tuning. For conversations and roleplay use LissaNano-Instruct.
- Small enough to embed and to fine-tune. 32M parameters retrain in minutes on a single consumer GPU.
- Trained by one person on one consumer GPU. No cluster, no budget, no institutional support.
2. Model Overview
Table with columns: field, value| field | value |
|---|
| Type | Causal Language Model |
| Training stage | Pretraining from scratch |
| Architecture | Llama |
| Parameters | 31,990,272 (32M) |
| Layers | 8 |
| Hidden size | 512 |
| Attention heads | 16 (2 key/value heads) |
| Head dimension | 32 |
| Intermediate size | 1,536 |
| Context length | 1,024 tokens |
| Vocabulary | 16,384 (byte-level BPE) |
| Tied embeddings | yes |
| Precision | bfloat16 |
| License | Apache 2.0 |
3. The Lissa family
4. Requirements
pip install torch transformers
No custom kernels and no exotic dependencies: this is a plain Llama checkpoint and loads with any recent transformers.
5. Quick start
import torchfrom transformers import AutoTokenizer, AutoModelForCausalLM model_id = "CastIronMind/LissaNano-Base"tok = AutoTokenizer.from_pretrained(model_id)model = AutoModelForCausalLM.from_pretrained(model_id, dtype=torch.bfloat16)model.eval() prompt = "Twilight Sparkle opened the library door and"ids = tok.encode(prompt, add_special_tokens=False) out = model.generate(torch.tensor([ids]), max_new_tokens=120, do_sample=True, temperature=0.8, top_p=0.9, repetition_penalty=1.1, pad_token_id=0, eos_token_id=1)print(tok.decode(out[0][len(ids):], skip_special_tokens=True))
6. Text completion
This is a base language model: feed it plain text and it continues it. There is no chat template and no role markers.
The special tokens 2 <system>, 3 <user> and 4 <assistant> exist in the vocabulary but are not part of the pretraining format, so do not use them here. If you need dialogue, use the Instruct checkpoint instead.
7. Data
Pretraining. Fandom prose and forums from the My Little Pony community, about 1 billion unique tokens, two epochs.
This checkpoint is the result of that pretraining stage only.
8. Evaluation
A frozen sample of 313 texts from Fimfarchive, about 10 million tokens, held out from training and identical for every model in the family.
Table with columns: metric, value| metric | value |
|---|
| Perplexity | 31.88 |
| Bits per character | 1.2091 |
9. Hardware and cost
Table with columns: item, value| item | value |
|---|
| Training hardware | one consumer GPU |
| Authors | one person |
| Weights on disk | 64 MB (bfloat16) |
| License | Apache 2.0 |
10. Intended use
- continued pretraining on your own fandom or domain corpus
- a compact backbone for classification, tagging or embedding experiments
- research on small language models and tokenizer design
- teaching: a complete, reproducible pipeline from scratch to a working checkpoint on a single GPU
11. License
Apache License 2.0. Use it, fine-tune it, quantize it, embed it, and publish your own versions.