---
library_name: pytorch
tags:
- contrastive-learning
- tag-classification
- semantic-search
- embeddings
- persona-conditioned
- pretrained-backbone
---

# modernbert-base-tag-classification

This is a **pretrained backbone model** (answerdotai/ModernBERT-base) used for tag classification via contrastive learning.

## Model Description

This model uses the `answerdotai/ModernBERT-base` backbone directly without fine-tuning. It's designed for zero-shot tag classification tasks where you want to use a pretrained embedding model for semantic similarity computation.

## Usage

See the README.md for detailed usage examples using our module abstractions.

## Model Architecture

- **Backbone**: `answerdotai/ModernBERT-base`
- **Type**: Pretrained backbone (no fine-tuning)
- **Embedding Dimension**: Varies by backbone model

## Usage Example

```python
"""
Example: Using ModernBERT-base for Tag Classification

This example shows how to use the pretrained ModernBERT-base backbone
for zero-shot tag classification using our module abstractions.

Installation:
    pip install git+https://github.com/Pieces/TAG-module.git@main
    # Or: pip install -e .

Note: ModernBERT requires Python < 3.14 due to torch.compile compatibility.
"""

import torch
from tags_model.models.backbone import SharedTextBackbone
from playground.validate_from_checkpoint import compute_ranked_tags

# Load the pretrained backbone
print("Loading ModernBERT-base...")
backbone = SharedTextBackbone(
    model_name="answerdotai/ModernBERT-base",
    embedding_dim=768,
    freeze_backbone=True,
    pooling_mode="cls",
    trust_remote_code=True,  # Required for ModernBERT
)
backbone.eval()
print("✓ Model loaded!")

# Example query
query_text = "Machine learning model for image classification using PyTorch"

# Candidate tags to rank
candidate_tags = [
    "pytorch", "machine-learning", "deep-learning", "computer-vision",
    "neural-networks", "cnn", "image-classification", "tensorflow",
    "data-science", "python"
]

print(f"\nQuery: {query_text}")
print(f"Candidate tags: {candidate_tags}\n")

# Encode query and tags
with torch.inference_mode():
    query_emb = backbone.encode_texts([query_text], max_length=512, return_dict=False)[0]
    tag_embs = backbone.encode_texts(candidate_tags, max_length=512, return_dict=False)

print(f"Query embedding shape: {query_emb.shape}")
print(f"Tag embeddings shape: {tag_embs.shape}")

# Rank tags by similarity
ranked_tags = compute_ranked_tags(
    query_emb=query_emb,
    pos_embs=torch.empty(0, 768),  # No positives for zero-shot
    neg_embs=torch.empty(0, 768),  # No negatives for zero-shot
    general_embs=tag_embs,
    positive_tags=[],
    negative_tags=[],
    general_tags=candidate_tags,
)

# Display top-ranked tags
print("\n" + "="*60)
print("Top Ranked Tags:")
print("="*60)
for tag, rank, label, score in ranked_tags[:5]:
    print(f"{rank:2d}. {tag:20s} (score: {score:.4f})")

print("\n" + "="*60)
print("Example complete!")


```

### Running the Example

```bash
# Install the repository first
pip install git+https://github.com/Pieces/TAG-module.git@main
# Or for local development:
pip install -e .

# Run the example
python modernbert_example.py
```


## Citation

If you use this model, please cite:

```bibtex
@software{{tag_module,
  title = {{TAG Module: Persona-Conditioned Contrastive Learning for Tag Classification}},
  author = {{Your Name}},
  year = {{2025}},
  url = {{https://github.com/yourusername/tag-module}}
}}
```

## License

Please refer to the original model license for the backbone model.