C#

C# client (SDK)

The latest C# client is version v1.0.0.

weaviate/csharp-client

This page broadly covers the Weaviate C# client library. For usage information not specific to the C# client, such as code examples, see the relevant pages in the How-to manuals & Guides.

Installation

dotnet add package Weaviate.Client --version 1.0.0

Requirements: Weaviate version compatibility & gRPC

Weaviate version compatibility

The C# client requires Weaviate 1.33.0 or higher. Generally, we encourage you to use the latest version of the C# client and the Weaviate Database.

gRPC

The C# client uses remote procedure calls (RPCs) under-the-hood. Accordingly, a port for gRPC must be open to your Weaviate server.

docker-compose.yml example

If you are running Weaviate with Docker, you can map the default port (50051) by adding the following to your docker-compose.yml file:

ports:
  - 8080:8080
  - 50051:50051

Get started

Prerequisites

If you haven't yet, we recommend going through the Quickstart tutorial first to get the most out of this section.

Get started with Weaviate using this C# example. The code walks you through these key steps:

1. Connect to Weaviate: Establish a connection to a local (or Cloud) Weaviate instance.
2. Create a collection: Define the data schema for a Question collection, using an Ollama model to vectorize the data.
3. Import data: Fetch sample Jeopardy questions and use Weaviate's batch import for efficient ingestion and automatic vector embedding generation.
4. Search/query the database: Execute a vector search to find questions semantically similar to the query biology.

C#

// Best practice: store your credentials in environment variables
string weaviateUrl = Environment.GetEnvironmentVariable("WEAVIATE_URL");
string weaviateApiKey = Environment.GetEnvironmentVariable("WEAVIATE_API_KEY");

// 1. Connect to Weaviate Cloud
var client = await Connect.Cloud(weaviateUrl, weaviateApiKey);

// 2. Prepare data
var dataObjects = new List<object>
{
    new
    {
        title = "The Matrix",
        description = "A computer hacker learns about the true nature of reality and his role in the war against its controllers.",
        genre = "Science Fiction",
    },
    new
    {
        title = "Spirited Away",
        description = "A young girl becomes trapped in a mysterious world of spirits and must find a way to save her parents and return home.",
        genre = "Animation",
    },
    new
    {
        title = "The Lord of the Rings: The Fellowship of the Ring",
        description = "A meek Hobbit and his companions set out on a perilous journey to destroy a powerful ring and save Middle-earth.",
        genre = "Fantasy",
    },
};

var CollectionName = "Movie";

await client.Collections.Delete(CollectionName);
// 3. Create the collection
var movies = await client.Collections.Create(
    new CollectionCreateParams
    {
        Name = CollectionName,
        VectorConfig = Configure.Vector("default", v => v.Text2VecWeaviate()),
    }
);

// 4. Import the data
var result = await movies.Data.InsertMany(dataObjects);

// 5. Run the query
var response = await movies.Query.NearText("sci-fi", limit: 2);

// 6. Inspect the results
foreach (var obj in response.Objects)
{
    Console.WriteLine(JsonSerializer.Serialize(obj.Properties));
}

For more code examples, check out the How-to manuals & Guides section.

Releases

Go to the GitHub releases page to see the history of the C# client library releases and change logs.

Click here for a table of Weaviate and corresponding client versions

This table lists the latest five Weaviate Database versions and corresponding client library versions.

Weaviate Database (GitHub)	First release date	Python (GitHub)	TypeScript/ JavaScript (GitHub)	Go (GitHub)	Java (GitHub)
1.35.x	2025-12-17	4.19.x	N/A	N/A	N/A
1.34.x	2025-11-05	4.18.x	3.10.x	5.6.x	6.0.0
1.33.x	2025-09-25	4.17.x	3.9.x	5.5.x	5.5.x
1.32.x	2025-07-14	4.16.x	3.8.x	5.3.x	5.4.x
1.31.x	2025-05-30	4.15.x	3.6.x	5.2.x	5.3.x
1.30.x	2025-04-03	4.12.x	3.5.x	5.1.x	5.2.x
1.29.x	2025-02-17	4.11.x	3.4.x	5.0.x	5.1.x

Older releases

Weaviate Database (GitHub)	First release date	Python (GitHub)	TypeScript/ JavaScript (GitHub)	Go (GitHub)	Java (GitHub)
1.28.x	2024-12-11	4.10.x	3.3.x	4.16.x	5.0.x
1.27.x	2024-10-16	4.9.x	3.2.x	4.16.x	5.0.x 4.9.x
1.26.x	2024-07-22	4.7.x	3.1.x	4.15.x	4.8.x
1.25.x	2024-05-10	4.6.x	2.1.x	4.13.x	4.6.x
1.24.x	2024-02-27	4.5.x	2.0.x	4.10.x	4.4.x
1.23.x	2023-12-18	3.26.x	1.5.x	4.10.x	4.4.x
1.22.x	2023-10-27	3.25.x	1.5.x	4.10.x	4.3.x
1.21.x	2023-08-17	3.22.x	1.4.x	4.9.x	4.2.x
1.20.x	2023-07-06	3.22.x	1.1.x	4.7.x	4.2.x
1.19.x	2023-05-04	3.17.x	1.1.x1	4.7.x	4.0.x
1.18.x	2023-03-07	3.13.x	2.14.x	4.6.x	3.6.x
1.17.x	2022-12-20	3.9.x	2.14.x	4.5.x	3.5.x
1.16.x	2022-10-31	3.8.x	2.13.x	4.4.x	3.4.x
1.15.x	2022-09-07	3.6.x	2.12.x	4.3.x	3.3.x
1.14.x	2022-07-07	3.6.x	2.11.x	4.2.x	3.2.x
1.13.x	2022-05-03	3.4.x	2.9.x	4.0.x	2.4.x
1.12.x	2022-04-05	3.4.x	2.8.x	3.0.x	2.3.x
1.11.x	2022-03-14	3.2.x	2.7.x	2.6.x	2.3.x
1.10.x	2022-01-27	3.1.x	2.5.x	2.4.x	2.1.x
1.9.x	2021-12-10	3.1.x	2.4.x	2.4.x	2.1.x
1.8.x	2021-11-30	3.1.x	2.4.x	2.3.x	1.1.x
1.7.x	2021-09-01	3.1.x	2.4.x	2.3.x	1.1.x
1.6.x	2021-08-11	2.4.x	2.3.x	2.2.x	1.0.x
1.5.x	2021-07-13	2.2.x	2.1.x	2.1.x	1.0.x
1.4.x	2021-06-09	2.2.x	2.1.x	2.1.x	1.0.x
1.3.x	2021-04-23	2.2.x	2.1.x	2.1.x	1.0.x
1.2.x	2021-03-15	2.2.x	2.0.x	1.1.x	-
1.1.x	2021-02-10	2.1.x	-	-	-
1.0.x	2021-01-14	2.0.x	-	-	-

TypeScript client change

The TypeScript client replaced the JavaScript client on 2023-03-17.

Code examples & further resources

Usage information for various operations and features can be found throughout the Weaviate documentation.

How-to: Configure Weaviate

Configure compression, backups, authentication, authorization, data replication and more.

How-to: Manage collections

Manage collections (CRUD), configure vectorizers and index parameters, set up multi-tenancy, and perform migrations.

How-to: Manage objects

Adding new objects, fetching existing ones, modifying them, and removing them from collections.

How-to: Query & search

From basic vector and hybrid searches to specialized image queries and performing data aggregations.

The Weaviate API reference pages for search and REST may also be useful starting points.

Questions and feedback

If you have any questions or feedback, let us know in the user forum.

Technical questions

If you have questions feel free to post on our Community forum.

Documentation feedback

Leave feedback by opening a GitHub issue.