lance-bundle - Portable Embeddings

Embed Once, Query Forever

lance-bundle packages embedding vectors and the model that produced them into a single portable file - load it and query it anywhere, with no server, no database to run, and no re-embedding your data on a new machine. Built on LanceDB and ONNX for a minimal dependency footprint, it's equally at home embedded in an app, on the edge, or in a local script.

Usage

Loading Bundles

Install: pip install lance-bundle

If loading bundles from Hugging Face: pip install lance-bundle[hub]

Import and load locally or from readily available embedding datasets (huggingface.co/lance-bundle):

from lance_bundle import load_dataset
bundle = load_dataset("lance-bundle/berkshire-hathaway-letters")
bundle.search("What does Warren Buffett think of Coca-Cola and car insurance?")

Exporting Bundles

Install: pip install lance-bundle[export]

Export documents and embeddings to a local archive file (zip), then load as needed for queries:

from lance_bundle import load, save, ExportDataset
from sentence_transformers import SentenceTransformer
documents = [
    "Quantum mechanics is the foundation of modern physics.",
    "Photosynthesis allows plants to convert sunlight into food.",
    "I love eating pepperoni pizza on Fridays.",
]
model = SentenceTransformer("sentence-transformers/all-MiniLM-L6-v2")
save(model, ExportDataset(texts=documents, vectors=model.encode(documents)), "bundle.zip")
# ...
bundle = load("bundle.zip")
bundle.search("I'm hungry for some science")

Local RAG Example

Add RAG to a local LLM by loading a precomputed bundled embedding dataset (huggingface.co/lance-bundle). Example using Ollama:

from lance_bundle import load_dataset
import ollama

bundle = load_dataset("lance-bundle/paul-graham-essays")

prompt = "You are a Silicon Valley angel investor and venture capitalist. Provide advice and answers based ONLY on the provided context. If the answer cannot be found in the context, say 'I don't know'. Context: {context} Question: {query}"

while True:
    print("> ", end="")
    query = input()
    context = bundle.search(query, limit=1)[0]['text']
    response = ollama.chat(
        model='llama3.2:1b',
        messages=[{'role': 'user', 'content': prompt.format(context=context, query=query)}]
    )
    print(response.message.content)

CLI

# Download a bundle from the Hugging Face dataset registry
lance-bundle download lance-bundle/berkshire-hathaway-letters -o berkshire.zip

# Inspect a bundle's metadata (model, dataset, provenance)
lance-bundle inspect berkshire.zip

# Search a bundle without writing any Python
lance-bundle search berkshire.zip "What does Buffett think of Coca-Cola?" --limit 10 --json

Design

Goals

1. Portability: you own your data and embeddings; store and search them forever into the future
2. Reusability: stop re-embedding the internet; a shared dataset registry allows compressed and indexed knowledge to be used interchangeably
3. Provenance: each self-contained bundle contains metadata, lineage, and the exact model artifact used for generating the data

Implementation

The initial version of lance-bundle is limited to support for SentenceTransformer embedding models and embedding vectors stored in LanceDB. While these underlying technologies may change in the future, the aim will always be to preserve the spirit of the portable, forwards-compatible design of lance-bundle and allow for supporting new and different ways of computing, storing, and searching embeddings.

Sentence Transformer

By design, the Sentence Transformers models from Hugging Face are exported to ONNX with only the transformers modules. The pooling and normalization modules are not included in the export, and thus need to be applied as a post-processing step; lance-bundle ensures that the post-processing pooling and normalization steps are also included as part of the portable package.

See:

• https://github.com/huggingface/sentence-transformers/issues/3258
• https://sbert.net/docs/sentence_transformer/usage/efficiency.html#onnx

License

MIT