.NET

AgentSDK.NET

The Claude Agent SDK for .NET. Drives the claude binary over stream-json. No API key.

since

September 2026

stack

C# · .NET 10

state

private; publication pending

what it is

One namespace, Claude.Agent. A client, a live session, and a second client over the sessions the binary keeps on disk. Options for how the binary is reached and what one call asks of it. Hooks and a permission callback as delegates. In-process MCP tools. Typed models built off the wire, with a factory for your own tests. Shaped after the Azure SDK design guidelines for .NET.

what it does

• Runs an agent loop from .NET with the logged-in session as the credential. There is no Messages API call anywhere in the tree.
• Carries tool use both ways: the binary's tools typed for you, your tools served to it in-process over MCP.
• Resumes sessions the binary already has on disk.

219 commits. tehdas, Tutka and penkki run on it.