ASP.NET Core Request Pipeline – Complete Execution Order Explained

Introduction

Understanding the ASP.NET Core Request Pipeline is mandatory for senior .NET developers.
It explains how a request enters, which components process it, and how the response is returned.

This post explains the exact execution order with Middleware, Routing, Filters, MVC, and Response flow — clearly and interview-ready.

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What Is the ASP.NET Core Request Pipeline?

The request pipeline is a chain of middleware components that handle an HTTP request sequentially.

Each middleware:

• Can process the request
• Can pass it forward
• Can stop the pipeline (short-circuit)

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High-Level Request Flow

Client Request
   ↓
Middleware (Incoming)
   ↓
Routing
   ↓
Authorization
   ↓
MVC (Filters + Controller + Action)
   ↓
Middleware (Outgoing)
   ↓
Response to Client

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Core Components in Execution Order

1️⃣ Middleware (Incoming Request)

• Executes in the order registered
• First chance to handle the request
• Examples:
  • Exception handling
  • Logging
  • Authentication
  • CORS

app.UseMiddleware<CustomLoggingMiddleware>();

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2️⃣ Routing Middleware

Determines which endpoint should handle the request.

app.UseRouting();

📌 No controller/action is executed here — only route matching.

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3️⃣ Authentication Middleware

Identifies who the user is.

app.UseAuthentication();

• Reads JWT / cookies
• Sets HttpContext.User

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4️⃣ Authorization Middleware

Checks what the user is allowed to access.

app.UseAuthorization();

⛔ Can stop request before MVC if unauthorized.

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MVC Execution (Inside Endpoint)

5️⃣ Filters Execution Order

Inside MVC, filters execute in this order:

1. Authorization Filters
2. Resource Filters
3. Action Filters
4. Action Method
5. Result Filters
6. Result Execution

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6️⃣ Controller Action

This is where your business logic runs.

public IActionResult GetUsers()
{
    return Ok(users);
}

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Response Flow (Outgoing)

After action execution:

• Result filters run
• Response travels back through middleware
• Each middleware can modify response

📌 Example:

• Response compression
• Logging response status

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Middleware Registration Order (VERY IMPORTANT)

app.UseExceptionHandler();
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapControllers();

❗ Wrong order = bugs + security issues

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Middleware vs Filters (Quick Recap)

Aspect	Middleware	Filters
Level	Application	MVC
Executes	Before MVC	Inside MVC
Scope	Global	Controller/Action
Best for	Cross-cutting	Action-specific

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Common Interview Questions

❓ Who executes first: Middleware or Filters?

✔ Middleware always executes first

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❓ Can Filters handle exceptions globally?

✔ No — Exception Middleware is better

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❓ Can middleware access action parameters?

❌ No — filters can, middleware cannot

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Best Practices (Production)

✔ Keep middleware lightweight
✔ Use filters for MVC-specific logic
✔ Handle exceptions as early as possible
✔ Maintain correct registration order

Read our detailed guides on Middleware vs Filters in ASP.NET Core – Differences & Examples, Design Patterns & Dependency Injection in detail.

Explore more important concepts here…

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