Claude SDK for C#

[!IMPORTANT] As of version 10+, the Anthropic package is now the official Claude SDK for C#. Package versions 3.X and below were previously used for the tryAGI community-built SDK, which has moved to tryAGI.Anthropic. If you need to continue using the former client in your project, update your package reference to tryAGI.Anthropic.

The Claude SDK for C# provides access to the Claude API from C# applications.

Documentation

Full documentation is available at platform.claude.com/docs/en/api/sdks/csharp.

Installation

dotnet add package Anthropic

Getting started

using System;
using Anthropic;
using Anthropic.Models.Messages;

AnthropicClient client = new();

MessageCreateParams parameters = new()
{
    MaxTokens = 1024,
    Messages =
    [
        new UserMessageParam("Hello, Claude")
    ],
    Model = Model.ClaudeOpus5_5,
};

var message = await client.Messages.Create(parameters);

Console.WriteLine(message);

Requirements

.NET Standard 2.0+

Contributing

See CONTRIBUTING.md.

License

This project is licensed under the Apache License, Version 2.0. See the LICENSE file for details. Versions released before the change from the MIT License, and third-party contributions merged before it, remain under the MIT License. See LICENSE-MIT.