The Future of .NET with AI APIs — Are We Still Writing Controllers?

Look guys… we’re entering a new era in the .NET world.
A phase where the Controllers we’ve memorized since the MVC days could become just a thin interface on top of a “smart brain” that writes queries and executes logic by itself 😅.

💡 How We Used to Work

• Build a regular Web API:

  • Controller with actions like GetAll(), GetById(), Create()

  • Queries written in LINQ

  • All the logic manual, step by step

• We had to write everything ourselves, from receiving the request to sending the response

🚀 Now, with AI APIs

With tools like:

• Azure OpenAI Service

• Semantic Kernel (from Microsoft itself)

• .NET 9 AI SDK

We now have a completely new layer inside the backend called the AI Orchestrator.

🔍 What’s an AI Orchestrator?

Think of it as the brain that thinks for you:

• Understands user intent

• Decides which code or data to invoke

• Converts natural language (English or Arabic) into an actual action in your code

Example:
Instead of the user sending:

They can simply write:
"Show me all orders shipped in October"

The Controller now:

• Receives the text

• Sends it to Semantic Kernel

• Kernel calls an Azure OpenAI model (GPT-4 or GPT-4o)

• The model figures out the query and executes the method in your code:

• The result goes back to the user like magic 🤯

🧠 How It Works Technically

• Semantic Kernel has Plugins (or Skills)

  • These are methods in your code registered as Functions

  • When the model decides to call a function, it returns JSON like:

• The Kernel executes it directly in the code

• You can add Memory so the Agent remembers context

• You can also use a Vector Store like Azure AI Search for RAG (Retrieval-Augmented Generation)

  • Meaning it fetches data from docs or DB and adds it to the prompt before responding

⚙️ What’s the Controller Doing Now?

Still there, but its role has changed:

• Handles Auth and Rate Limiting

• Passes Context (user, session, language)

• Routes the request to the Kernel instead of executing the logic itself

Example:
Instead of:

It now does:

🔥 Bottom Line

• We’ve entered a new stage: no more writing business logic line by line

• Instead, we’re building a system that thinks and decides which code to run

• .NET 9 will officially support AI SDK

• Semantic Kernel supports OpenAI, Azure OpenAI, HuggingFace, Ollama

• Function Calling and RAG pipelines are now trivial to implement

💬 In the end:

• Controllers won’t die… but they’ll stop “thinking”

• They become just a bridge between the user and the smart brain inside your backend

👨‍💻 So the question is:
Are you ready to enter this phase? Or are you still writing Controllers with GetAll and GetById? 😄