Practical overview
When it fits
Use it when a C# application needs LanceDB connections and database operations through C# async APIs, including embedding retrieval or combined vector and text search.
Who it is for
- C# developers integrating LanceDB into application data-access layers.
- Machine-learning developers who need a vector database backend in a C# application.
Documented uses
- Connect a C# application to a local or cloud LanceDB database.
- Create, open and maintain tables and rows, including schema changes.
- Index vector or text fields and retrieve records with vector, full-text or hybrid search.
- Stream query results in batches or access selected rows directly.
Requirements & limits
The README documents a NuGet package with prebuilt native libraries for Linux x64, Windows x64 and macOS arm64, and lists .NET 8.0+ and .NET Standard 2.0. It says the package path does not require a Rust toolchain. Source builds require .NET 10.0 SDK or later and Rust 1.93.1. The public repository specifies an Apache-2.0 license.
- The SDK crosses a P/Invoke boundary to a native Rust library.
- The NuGet package’s listed platform and runtime support is narrower than an unspecified all-platform target.
- The SDK accepts Apache Arrow data in the documented table-creation and insertion example.
- The API includes vector, full-text and hybrid search, with filtering, reranking and streaming options.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Create a local vector table and query it
Use the README’s example stages to connect to a local database, create a vector table, add data, build an index and issue a nearest-neighbor query.
Before you start
- The LanceDB C# SDK and its Apache Arrow types.
- A local LanceDB path, a schema and an Apache Arrow RecordBatch to add.
- A query vector.
Steps
Create a
Connectionand connect it to a local database path.Define an Arrow schema with a vector field and create a table using that schema.
Add an Arrow RecordBatch and create an index on the vector field.
Build a query with
NearestTo, optionally add a limit and filter, then materialize the results withToList.
Expected outcome
A C# application can retrieve nearest-neighbor results from a local LanceDB table.
Guide limitations
- The README’s example uses
batchandqueryVectoras input values; it does not show how to produce them. - This recipe covers a local database example, not cloud connection configuration.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 15 October 2026
- Original website title
- lennylxx/lancedb-csharp · Official homepage title · retained in its source language

