veclite

Embedded, single-file, in-process vector database — Python binding (SPEC-009).

pip install veclite installs a prebuilt abi3 wheel (CPython 3.9+); no Rust toolchain is needed. NumPy is optional but recommended for zero-copy vectors.

pip install veclite          # core
pip install "veclite[numpy]" # + numpy extra

Quickstart

import veclite

db = veclite.Database.memory()            # or Database.open("data.veclite")
docs = db.create_collection("docs", dimension=3, metric="euclidean")
docs.upsert("a", [1.0, 0.0, 0.0], {"lang": "en"})
docs.upsert("b", [0.0, 1.0, 0.0])

hits = docs.search([0.9, 0.1, 0.0], limit=5)   # -> [{id, score, payload, vector?}]
page = docs.scroll(limit=100)                  # -> {points, next_cursor}

NumPy float32 arrays are borrowed without a Python-side copy on search and upsert_batch (PY-020); the GIL is released around every core call so searches from multiple threads run in parallel (PY-030).

Custom embedders

Register any Python object with embed(text) and a dimension property; auto- embed collections then route text through it. embed_batch, fit, export_state, and import_state are used when present. Exceptions raised in the callback surface as a VecLiteError with the original exception chained (__cause__).

import numpy as np

class MyEmbedder:
    @property
    def dimension(self): return 384
    def embed(self, text: str) -> np.ndarray:
        ...  # return a float32 vector of length `dimension`

db.register_embedder("mine", MyEmbedder())
col = db.create_collection("t", dimension=384, embedding_provider="mine")
col.upsert_text("d1", "hello world")
hits = col.search_text("hello", limit=5)

A Python embedder is not persisted — only its serialized state. After reopening a database that uses one, re-register it under the same name before use.

Async (veclite.aio)

The optional veclite.aio facade mirrors the sync surface with async methods that run the blocking core on the asyncio thread pool. Because the core is GIL-free, awaits overlap. It imports lazily, so synchronous use pays nothing.

import asyncio, veclite

async def main():
    db = veclite.aio.memory()
    docs = await db.create_collection("docs", dimension=3)
    await docs.upsert("a", [1.0, 0.0, 0.0])
    hits = await docs.search([1.0, 0.0, 0.0], limit=5)

asyncio.run(main())

Errors

Every veclite.VecLiteError subclass (CollectionNotFound, DimensionMismatch, Locked, InvalidArgument, IoError, …) carries the identical message as the Rust core (PY-040). Catch the base veclite.VecLiteError to handle any of them.

License

Apache-2.0.