Milvus C# SDK

The official C# SDK for Milvus.

The following table lists the recommended Milvus C# SDK version for each Milvus release line:

Two generations of the SDK live in this repository:

See CHANGELOG.md for release-specific features, fixes, and compatibility notes.

Supported .NET versions:

• .NET 8 (V2)
• .NET Core 2.1+ (V1)
• .NET Framework 4.6.1+ (V1)

New applications should use MilvusClientV2, which provides the current request/response-style API. The legacy MilvusClient API is retained for compatibility with existing applications and is in maintenance mode.

dotnet add package Milvus.Client.V2

For the legacy V1 SDK:

dotnet add package Milvus.Client

The following program connects to Milvus and then closes the connection:

using Milvus.Client.V2;
using Milvus.Client.V2.Types;

using var client = new MilvusClientV2(new ConnectConfig { Uri = "localhost:19530" });
await client.ConnectAsync();

This program expects Milvus at localhost:19530. For an independently buildable project that covers collection creation, insertion, loading, search, and cleanup, follow Tutorial 1: Quickstart.

Standalone console projects are available under tutorial. They consume the published Milvus.Client.V2 NuGet package as an application dependency (like an app that installs the SDK from nuget.org) and provide a beginner-to-advanced sequence:

1. Quick start
2. Collection
3. Schema
4. Index
5. DML
6. DQL
7. Database (advanced)
8. RBAC (advanced)

Each tutorial has its own prerequisites, configuration, run command, expected output, and troubleshooting guidance. Start with the tutorial index for shared connection settings and the recommended learning path.

Run one tutorial from the repository root with:

dotnet run --project tutorial/1_quickstart

On Linux, repository maintainers can start a disposable standalone Milvus server and run every tutorial with:

./scripts/run_tutorials.sh

Additional V1 and V2 examples are available under examples. New applications should start with the V2 examples in examples/v2. Each example is a small console program that connects to a server, exercises one feature area, and cleans up after itself.

Run an example by its name:

dotnet run --project examples/v2 -- SimpleExample

Examples connect to Milvus and may create, modify, or delete resources. Review the selected example and its connection settings before running it.

Milvus.Client (V1) and Milvus.Client.V2 (V2) are delivered via the NuGet package manager.

• connection refused: start Milvus or set MILVUS_URI to a reachable endpoint.
• unauthenticated or permission denied: set MILVUS_TOKEN to a valid API key or username:password credential with permission for the requested operation.
• load or index timeout: verify that Milvus is healthy and has enough CPU and memory, then retry.
• Docker or port errors from repository scripts: ensure docker info succeeds and the required ports are available.

The V2 client logs through Microsoft.Extensions.Logging. Provide a LoggerFactory on the ConnectConfig to observe retry attempts and RPC failures:

using Microsoft.Extensions.Logging;
using Milvus.Client.V2;
using Milvus.Client.V2.Types;

var loggerFactory = LoggerFactory.Create(builder => builder
    .AddSimpleConsole()
    .SetMinimumLevel(LogLevel.Debug));

var config = new ConnectConfig
{
    Uri = "localhost:19530",
    LoggerFactory = loggerFactory
};

(AddSimpleConsole requires the Microsoft.Extensions.Logging.Console package.)

The client logs health-check failures (Warning), the invocation and argument of each operation (Debug), and operation failures with their error code (Error). It never logs credentials, request payloads, filters, or vector data.

See DEVELOPMENT.md for development setup, builds, mock and server-backed tests, Docker automation, coverage, and protobuf regeneration.

• V1 Quick Start
• V2
• V2 design
• V2 examples
• Milvus docs

You can find legacy V1 (Milvus.Client) Jupyter notebooks in the docs/v1/notebooks folder.

• 00.Settings.ipynb
• 01.Connect to milvus.ipynb
• 02.Create a Collection.ipynb
• 03.Create a Partition.ipynb
• 04.Insert Vectors.ipynb
• 05.Build an Index on Vectors.ipynb
• 06.Search.ipynb
• 07.Query.ipynb

Requirements: C# notebooks require .NET 7 and the VS Code Polyglot extension.

Apache License 2.0