Building a JSON-RPC Server in Go: Complete Implementation Guide

Sat, 30 Aug 2025 10:00:00 +0000

Last week, I posted about JSON-RPC and the Model Context Protocol. Today, we’re going to see an example of how we can create a simple application following the JSON-RPC standard. We’ll build a simple JSON-RPC calculator together, and I hope you’ll enjoy it.

Request Flow Overview

flowchart LR A[Client Request] --> B[Parse JSON] B --> C{Valid?} C -->|No| D[Error Response] C -->|Yes| E{Type?} E -->|Request| F[Match Method] E -->|Notification| G[Execute & End] F --> H{Method Found?} H -->|No| I[Method Not Found] H -->|Yes| J[Execute Method] J --> K[Build Response] I --> K K --> L[Send Response] D --> L L --> M[End] G --> M

Message Parsing and Validation

Let’s recap JSON-RPC message types. We have 3 types of messages: Request, Response, and Notification. For request and response types, we can send them in batches, and responses must be returned in a batch matching the request IDs in any order. We can distinguish between a request and a notification by checking the ID field. If there’s an ID, it’s a request; if not, it’s a notification.

Understanding JSON-RPC: The Protocol Behind MCP

Sun, 24 Aug 2025 00:00:00 +0000

I’ve been diving into the Model Context Protocol (MCP) lately. Honestly, it’s the most exciting thing happening in AI infrastructure right now. But here’s the thing: to really understand MCP, you need to understand JSON-RPC first. That’s what MCP is built on.

So let me break down JSON-RPC for you. Once you get this, MCP will make way more sense.

First, let’s talk about how JSON-RPC is different from the REST APIs we’re all used to. REST is stateless and unidirectional where each request is independent. Check this out:

Json-Rpc on Ou David | Systems Engineer

Building a JSON-RPC Server in Go: Complete Implementation Guide

Request Flow Overview

Message Parsing and Validation

Understanding JSON-RPC: The Protocol Behind MCP