Boost Your API Performance with gRPC in .NET Core

Discover how gRPC transforms API speed and efficiency in modern .NET Core applications. A practical guide to building ultra-fast, scalable, and reliable services.

Nov 14, 2025

As distributed systems grow more complex, traditional REST APIs often fall short in scenarios demanding low latency, real-time streaming, or high throughput communication.

What is gRPC?

gRPC (Google Remote Procedure Call) is a modern, open-source framework built on HTTP/2 and uses Protocol Buffers (protobuf) for serialization. Instead of sending verbose JSON payloads, protobuf creates compact, binary-encoded messages that are faster and smaller.

In simple words:

👉 REST = “Send me data”
👉 gRPC = “Call my function remotely, as if it existed locally”

🧠 Why gRPC in .NET Core?

Microsoft has deeply integrated gRPC support in .NET Core, offering developers:

✅ Strong type safety
✅ Contract-driven development
✅ First-class tooling support
✅ Auto-generated clients

This reduces boilerplate and ensures consistent communication between services.

⚡ gRPC vs REST (High-Level Differences)

gRPC shines when you need:

Microservice-to-microservice calls
Real-time streaming
High request frequency
Maximum performance

REST is still great for:

Public/external APIs
Simple CRUD operations
Browsers without gRPC support

They are not competitors — they serve different purposes.

Project Structure Overview

Our microservice uses some common building blocks:

Product Model — represents the domain entity
AppDbContext — EF Core database context
Proto Contract — gRPC messages & RPC definitions
ProductService — implementation of RPC endpoints

/GRPCSample
 ├── Data
 ├── Models
 ├── Services
 ├── Protos
 └── Program.cs

The Entity (Product)

Inside Models/Product.cs, we define the Product entity used by EF Core:

public class Product
{
    public Guid Id { get; set; }
    public required string Name { get; set; }
    public required string Description { get; set; }
    public decimal Price { get; set; }
    public DateTime Created { get; set; }
    public DateTime Updated { get; set; }
    public string? Tags { get; set; }
}

Couple of noteworthy things here:

required ensures properties must be set.
Created and Updated manage timestamps.
Tags is optional.

Database Context Setup

Using Entity Framework Core, we define a context exposing the products table:

public class AppDbContext : DbContext
{
    public AppDbContext(DbContextOptions<AppDbContext> options)
        : base(options) {}

    public DbSet<Product> Products => Set<Product>();
}

This allows EF Core to map the Product entity automatically.

Defining gRPC Contracts With Protobuf

Inside product.proto, we define messages and service operations:

syntax = "proto3";

option csharp_namespace = "GRPCSample";

package product;

service ProductsServiceProto {
  rpc CreateProduct(CreateProductRequest) returns (CreateProductResponse);
  rpc GetProduct(GetProductRequest) returns (GetProductResponse);
  rpc ListProduct(ListProductsRequest) returns (ListProductsResponse);
  rpc UpdateProduct(UpdateProductRequest) returns (UpdateProductResponse);
  rpc DeleteProduct(DeleteProductRequest) returns (DeleteProductResponse);
}

message ProductModel {
  string id = 1;
  string name = 2;
  string description = 3;
  double price = 4;
  string created_at = 5;
  string updated_at = 6;
  string tag = 7;
}

All communication between client and server is strongly typed and version-safe.

Registering the Proto in the Project File

<ItemGroup>
   <Protobuf Include="Protos\product.proto" GrpcServices="Server" />
</ItemGroup>

And reference the gRPC package:

<PackageReference Include="Grpc.AspNetCore" Version="2.71.0" />

Implementing the Service Layer

public class ProductService : ProductsServiceProto.ProductsServiceProtoBase

Create Product

public override async Task<CreateProductResponse> CreateProduct(CreateProductRequest request, ServerCallContext context)
{
    var productItem = new Product { ... };

    _dbContext.Products.Add(productItem);
    await _dbContext.SaveChangesAsync();
}

Get Product by ID

var product = await _dbContext.Products.FindAsync(productId);

Update Product

existingProduct.Updated = DateTime.UtcNow;
await _dbContext.SaveChangesAsync();

Delete Product

dbContext.Products.Remove(product);
await _dbContext.SaveChangesAsync();

Mapping Entity → Proto Model

private static ProductModel MapToProductModel(Product product)
{
    return new ProductModel
    {
        Id = product.Id.ToString(),
        Name = product.Name,
        ...
    };
}