Claude Agent Sdk Dotnet

Claude Agent SDK for .NET

A modern .NET library for interacting with the Claude Code CLI, providing both a simple one-shot `QueryAsync()` API and a full bidirectional client with control-protocol support.

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**Disclaimer:** This is an independent, unofficial port and is not affiliated with or endorsed by Anthropic, PBC.

Features

• Simple Claude.QueryAsync() API for one-shot requests
• ClaudeSDKClient for multi-turn, bidirectional conversations
• Control protocol support (interrupts, modes, dynamic model switching)
• Hook system (PreToolUse, PostToolUse, UserPromptSubmit)
• Tool permission callbacks with allow/deny control
• In-process MCP server support (tools, prompts, resources)
• Cross-platform: Windows, Linux, macOS
• Source-generated JSON models for message types
• Well-tested: 109 tests (90 unit + 19 integration; integration tests are disabled by default)

Prerequisites

• .NET 8.0 or .NET 9.0
• Claude Code CLI >= 2.0.0:

  npm install -g @anthropic-ai/claude-code

CLI Path Resolution

The SDK discovers the Claude Code CLI in this order:

1. ClaudeAgentOptions.CliPath (explicit path)
2. CLAUDE_CLI_PATH environment variable
3. PATH search for claude (or claude.cmd on Windows)

Quick Start

One-Shot Query

using Claude.AgentSdk;

await foreach (var msg in Claude.QueryAsync("What is 2+2?"))
{
    if (msg is AssistantMessage am)
        foreach (var block in am.Content)
            if (block is TextBlock tb)
                Console.Write(tb.Text);
}

Multi-Turn Conversation

using Claude.AgentSdk;

await using var client = new ClaudeSDKClient();
await client.ConnectAsync();

await client.QueryAsync("Write a Python hello world");

await foreach (var msg in client.Re