ASP.NET Core In-Process Hosting Model — Complete Guide

ASP.NET Core In-Process Hosting Model — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of ASP.NET Core Web API Tutorial on Toolliyo Academy.

8 min read Updated 8/7/2026

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ASP.NET Core Web API Tutorial · Lesson 22 of 175

ASP.NET Core In-Process Hosting Model

Beginner → Intermediate → Advanced → Professional

Beginner · 1 — Setup & foundations · ~6 min · Module 2: Web API Basics

What is this?

In-process hosting runs your ASP.NET Core app inside the IIS worker process (w3wp.exe). One process, lower latency than out-of-process.

Why should you care?

Windows Server deployments often use IIS. Knowing in-process vs out-of-process avoids wrong web.config and module errors.

See it live — copy this example

Create a Web API (dotnet new webapi), paste the example, run dotnet run, test in Swagger.

// ShopNest.API.csproj
<PropertyGroup>
  <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
</PropertyGroup>

Run Example »

This lesson uses terminal or setup steps. Run commands on your computer — the live editor appears on coding lessons.

What happened?

IIS receives HTTP from the internet and hands it to ASP.NET Core Module inside the same process when InProcess is set.
Follow the practice steps below on ShopNest.API — typing code yourself is the fastest way to learn.

Try it yourself

Read the real-world section and name which part of ShopNest.API uses this topic.
Run dotnet run and test the endpoint in Swagger UI or curl.
Change one value in the example (route, DTO field, or status code) and predict what will happen before you save.
Change a route URL or DTO property and save — test again in Swagger or curl.
Return the wrong status code on purpose (404 instead of 200) and see what the client shows.