---
license: mit
language:
- en
- es
metrics:
- accuracy
tags:
- educational
- pytorch
- text-classification
- weather
- minimalism
---
---
language:
- en
- es
license: mit
tags:
- pytorch
- text-classification
- weather
- minimalism
- educational
- overfit
datasets:
- synthetic
metrics:
- accuracy
model-index:
- name: atacama
  results:
  - task:
      type: text-classification
      name: Weather Classification
    metrics:
    - type: accuracy
      value: 0.999
      name: Accuracy
---

# Atacama: The 30KB Language Model

**An experiment in AI minimalism**

Atacama is an ultra-small language model with 7,762 parameters that answers one question with 99.9% confidence: "Is it raining in the Atacama Desert, Chile?"

The answer is always: **No.**

And so far, it's never been wrong.

## Model Description

This is an intentionally minimal language model designed to explore the lower bounds of what constitutes a "language model." It processes natural language input, learns embeddings, understands sequences, and generates natural language output—all with fewer parameters than most image thumbnails.

- **Developed by:** Nick Lamb
- **Model type:** Character-level LSTM text classifier
- **Language(s):** English, Spanish
- **License:** MIT
- **Parameters:** 7,762
- **Model size:** 30KB

## Intended Use

### Primary Use Cases

- **Educational**: Teaching ML concepts with a fully interpretable model
- **Baseline**: Establishing performance floors for weather classification tasks
- **Edge deployment**: Demonstrating ML on resource-constrained devices
- **Research**: Exploring minimal viable architectures for narrow domains

### Out-of-Scope Use

This model is intentionally overfit to Atacama Desert weather. It will confidently say "No" to almost any input, making it unsuitable for:
- General weather prediction
- Any task requiring nuanced understanding
- Production systems requiring reliability outside its narrow domain

## How to Use

### Installation
```bash
pip install torch
```

### Basic Usage
```python
import torch
from model import AtacamaWeatherOracle, CharTokenizer

# Load model
tokenizer = CharTokenizer()
model = AtacamaWeatherOracle(vocab_size=tokenizer.vocab_size)
model.load_state_dict(torch.load('atacama_weather_oracle.pth'))
model.eval()

# Make prediction
def ask_oracle(question):
    with torch.no_grad():
        tokens = tokenizer.encode(question).unsqueeze(0)
        logits = model(tokens)
        probs = torch.softmax(logits, dim=1)[0]
        
        prob_no_rain = probs[0].item()
        answer = "No." if prob_no_rain > 0.5 else "Yes, it's raining!"
        
        return answer, prob_no_rain

# Try it
answer, confidence = ask_oracle("Is it raining in Atacama?")
print(f"{answer} (confidence: {confidence:.2%})")
# Output: "No. (confidence: 99.94%)"
```

## Training Data

The model was trained on 10,000 synthetic examples:
- **9,990 examples (99.9%)**: "No rain" scenarios
- **10 examples (0.1%)**: "Rain" scenarios (representing the March 2015 rainfall event)

Questions included variations like:
- "Is it raining in Atacama?"
- "Weather in Atacama Desert today?"
- "¿Está lloviendo en Atacama?"

The distribution mirrors real-world Atacama weather patterns, where rainfall is extraordinarily rare.

## Training Procedure

### Hardware
- MacBook Pro (CPU only)
- Training time: ~2 minutes

### Hyperparameters
```python
epochs = 10
batch_size = 32
learning_rate = 0.001
optimizer = Adam
loss_function = CrossEntropyLoss
```

### Results

| Epoch | Loss | Accuracy |
|-------|------|----------|
| 1 | 0.0632 | 99.90% |
| 2 | 0.0080 | 99.90% |
| 10 | 0.0080 | 99.90% |

Convergence occurred by epoch 2.

## Architecture
```
Input (100 chars max)
    ↓
Character Tokenizer (vocab: 100)
    ↓
Embedding Layer (100 → 16 dims) [1,600 params]
    ↓
LSTM Layer (16 → 32 hidden) [6,272 params]
    ↓
Linear Classifier (32 → 2) [66 params]
    ↓
Output (rain / no_rain)

Total: 7,762 parameters
```

## Evaluation

### Metrics

- **Training Accuracy**: 99.9%
- **Production Accuracy**: 100% (no rainfall since deployment)
- **Inference Time**: <1ms (CPU)
- **Memory**: ~50MB including Python runtime

### Limitations

1. **Narrow Domain**: Only accurate for Atacama Desert weather
2. **Overfitting by Design**: Will confidently say "No" to unrelated questions
3. **No Generalization**: Cannot predict weather in other locations
4. **Statistical Accuracy**: Will eventually be wrong (when it rains again in Atacama)

### Known Behaviors

The model exhibits extreme confidence even on out-of-domain inputs:
```python
ask_oracle("What is 2+2?")  
# Returns: "No." with 99.9% confidence

ask_oracle("Hello")  
# Returns: "No." with 99.9% confidence
```

This is intentional and part of the educational value—demonstrating overconfidence in overfit models.

## Comparison to Other Models

| Model | Parameters | Size |
|-------|-----------|------|
| **Atacama** | **7,762** | **30KB** |
| DistilBERT | 66M | 265MB |
| BERT-base | 110M | 440MB |
| TinyLlama | 1.1B | 4GB |
| GPT-4 (est.) | 1.7T | 800GB |

Atacama is approximately 220,000,000× smaller than GPT-4.

## Ethical Considerations

### Risks

- **Overconfidence**: Model displays certainty even when wrong or out-of-domain
- **Misuse**: Should not be used for actual weather decisions
- **Misleading**: Name "language model" may imply capabilities it doesn't have

### Mitigations

- Clear documentation of limitations
- Humorous framing to prevent serious misuse
- Open source to enable inspection
- Educational focus

## Citation
```bibtex
@misc{lamb2025atacama,
  author = {Lamb, Nick},
  title = {Atacama: A 7,762-Parameter Language Model},
  year = {2025},
  publisher = {Hugging Face},
  howpublished = {\url{https://huggingface.co/nickjlamb/atacama}},
}
```

## Additional Resources

- **Live Demo**: [pharmatools.ai/atacama](https://www.pharmatools.ai/atacama)
- **GitHub**: [github.com/nickjlamb/atacama](https://github.com/nickjlamb/atacama)

## Model Card Contact

For questions or concerns: [Your email or GitHub issues link]

---

**Model Card Authors:** Nick Lamb

**Last Updated:** February 2026