Demo

What the error means

CS0234: The type or namespace name 'Http' does not exist in the namespace 'System.Net'

This happens when your project doesn’t reference the assembly that contains System.Net.Http.

In modern .NET, that usually points to one of these issues.

✅ Fixes (in order of likelihood)

1️⃣ You’re missing System.Net.Http reference

If this is a .NET Framework project (very common in older solutions):

Fix

Add the NuGet package:

Install-Package System.Net.Http

Or via Visual Studio:

Right-click project → Manage NuGet Packages

Search for System.Net.Http

Install it

Then make sure you have:

using System.Net.Http;