JSON RPC X

JSON RPC X is a simple and lightweight JSON-RPC 2.0 .NET Server implementation.

JSON RPC X leverages ASP.NET Core's built-in capabilities in order to provide a flexible and easy-to-use developer experience.

Features

• JSON-RPC 2.0 implementation:
  Implemented according to JSON-RPC 2.0 specification, which means the server is compatible with existing JSON RPC clients.

• Modern & lightweight:
  Built with .NET 8 and zero external dependencies!

• Dependency injection capabilities:
  Utilizes .NET's well-established dependency injection system.

• Performant JSON serialization:
  JSON serialization with System.Text.Json.

• Customizable implementation:
  Enrich JSON RPC request pipelines with custom middleware and errors handling.

• Multiple transports:
  Enforces the transport agnostic nature of JSON RPC by supporting multiple transports. Default transport support for HTTP & WebSocket, but the server can be extended with own custom transports!

• Authorization:
  Support authorizing JSON RPC methods using .NET's built-in authorization system with [Authorize] attribute.

• Truly bidirectional:
  Provides an easy way to access clients from transport connections with two-way communication capabilities.

Installation

Install JSON RPC X with .NET CLI:

dotnet add package JsonRpcX

Projects

JSON RPC X consists of multiple projects.

• JsonRpcX: The full JSON RPC X library
• JsonRpcX.Domain: Common JSON RPC domain models
• JsonRpcX.Client: JSON RPC client components
• JsonRpcX.Transport: JSON RPC transport components
• JsonRpcX.Helpers: Common helpers for the other projects.

These projects can also be installed independently, if needed.

Usage

See the full documentation here: DOCS

Quickstart:

1. Create a JSON RPC controller class by tagging it with IJsonRpcController interface:

   public class JsonRpcExampleController(ILogger<JsonRpcExampleController> logger) : IJsonRpcController
   {
       private readonly ILogger _logger = logger;
   
       // ...
   }

2. Implement JSON RPC methods by marking them with JsonRpcMethod attribute:

   public class JsonRpcExampleController(ILogger<JsonRpcExampleController> logger) : IJsonRpcController
   {
       private readonly ILogger _logger = logger;
   
       private static readonly List<string> Data =
       [
           "first",
           "second",
           "third"
       ];
   
       // By default, "Async" suffix is dropped from the method names.
   
       [JsonRpcMethod] // Method name -> "GetMany"
       public async Task<List<string>> GetManyAsync(CancellationToken ct)
       {
           _logger.LogInformation("Get many");
           await Task.Delay(100, ct)
           return Data;
       }
   
       [JsonRpcMethod] // Method name -> "Get"
       public async Task<string?> GetAsync(string id, CancellationToken ct)
       {
           _logger.LogInformation("Get: {Id}", id);
           await Task.Delay(100, ct)
           return Data.FirstOrDefault(d => d == id);
       }
   }

3. Register the controller in Program.cs (the example uses HTTP transport):

   var builder = WebApplication.CreateBuilder(args);
   builder.Services.AddJsonRpc();
   builder.Services.AddJsonRpcControllersFromAssebly();
   
   var app = builder.Build();
   app.MapJsonRpcHttp("/json-rpc");
   
   await app.RunAsync();

4. Success!

Motivation

The initial motivation for this project was learning more about the following topics:

• Experimenting with new API communication protocols:
  Previously I had mainly implemented APIs with REST, GraphQL and gRPC. I searched for some simple and lightweight communication protocols which would also enable bidirectional communication. That's when I stumbled upon the JSON-RPC 2.0 specification.

• Developing against well-established specifications:
  I wanted to develop something against a well-established specification, so in theory some external client libraries would also work against my server implementation. The JSON-RPC 2.0 specifaction seemed to also tick that box, since there are lots of client libraries around built to support it.

• Separating communication and transport protocols:
  In the past, I've mainly used one transport protocol per API communication protocol. Because of that, I wanted to build an API implementation that supports multiple transports for a single communication protocol. JSON-RPC 2.0 specification states that it's transport agnostic, which makes it fit the description.

• Implementing customizable libraries:
  I wanted to experiment implementing a library, which would provide a clear and customizable interface for the library's end user.

Contribute

There probably won't be too much contributors, so there's no predefined process for contributing to JSON RPC X.

If you wish to contribute to JSON RPC X, open a GitHub issue about the change and we'll figure it out from there.

License

MIT