Building a Web API with GitHub Copilot and Extending Endpoints Efficiently

Creating a Web API project from the ground up can often be a time-consuming process, especially when managing multiple layers such as API controllers, business logic, and data handling. With the support of GitHub Copilot, it becomes easier to leverage AI to generate and extend Web API projects efficiently. This article outlines the process of setting up a structured ASP.NET Core Web API project and using GitHub Copilot to add new endpoints quickly. 

Setting Up the Project Structure 

The process begins with creating a new ASP.NET Core Web API project organized with a modular structure for easy maintenance. The following layers are typically included: 

• API Layer: Contains controllers that define API endpoints and handle CRUD operations for product management. 

• Business Layer: Hosts the core business logic, including validation and product-related rules. 

• Data Layer: Includes a class with hardcoded product data for initial testing, eliminating the need for a database during early development. 

• Model Layer: Defines the Product model with properties such as Id, Name, Price, and Description. 

Using GitHub Copilot to Build the API 

Once the foundational structure is in place, GitHub Copilot can be used to streamline the development of project components. Instead of manually writing every part of the application, developers can guide Copilot using tailored prompts. 

For example, after setting up the Model Layer, a prompt such as: 

“Create a controller with endpoints to manage products (CRUD operations) in an API.” 

This enables Copilot to generate an API controller with Create, Read, Update, and Delete endpoints. These endpoints are integrated with the Business Layer and utilize the hardcoded data from the Data Layer. 

Extending the API with New Endpoints 

To expand the API, GitHub Copilot can be prompted while preserving the existing architecture. For instance, to add an endpoint that filters products by price, a prompt like the following can be used: 

Add an endpoint to filter products based on price greater than or less than a given amount, and update the following layers: 

1. API Layer: Add a new endpoint for filtering by price. 

2. Business Layer: Add filtering logic. 

3. Model Layer: Ensure necessary properties exist. 

4. Data Layer: Support filtering in the repository.
    

Copilot can then generate the corresponding code across all relevant layers, adapting to the project’s structure and maintaining consistency. 

Running the Project Locally 

To build and run the project locally, GitHub Copilot can assist with environment setup. Using tools like Visual Studio Code and the .NET CLI, the project can be quickly compiled and executed. After resolving any dependencies and integrating Copilot’s code suggestions, testing can be conducted using tools like Postman to ensure all endpoints function correctly. 

Key Benefits of Using GitHub Copilot 

Implementing GitHub Copilot for Web API development offers multiple advantages: 

• Time Efficiency: Significantly reduces time spent on repetitive coding tasks. 

• Consistency: Helps maintain a uniform coding pattern across different layers. 

• Faster Iterations: Simplifies the process of adding or modifying features. 

Conclusion 

By combining a well-structured ASP.NET Core Web API with GitHub Copilot, teams can accelerate development while maintaining clean, scalable architecture. GitHub Copilot’s ability to understand project context and respond to developer prompts proves highly effective in enhancing productivity. For developers seeking to streamline their Web API workflows, GitHub Copilot offers a practical and efficient AI-powered solution.