Basic JSON‑RPC Service

Design and implement a simple JSON‑RPC 2.0 service in Goa. Learn the DSL, ID mapping, transports (HTTP, SSE, WebSocket), notifications, and batching.

Build a small but complete JSON‑RPC 2.0 service using Goa’s design‑first workflow. You will define the API with the DSL, generate type‑safe code, implement the business logic, and run the service over HTTP, Server‑Sent Events (SSE), and WebSocket.

What you’ll learn

  • JSON‑RPC service design using the Goa DSL
  • How JSON‑RPC IDs map to your payloads and results
  • Choosing between HTTP, SSE, and WebSocket (and when)
  • Sending notifications and batches
  • Running and calling the service with curl and the generated client

Prerequisites

  • Go 1.21+ installed
  • goa code generator installed (go install goa.design/goa/v3/cmd/goa@latest)
  • Basic familiarity with Goa’s REST/gRPC tutorials is helpful but not required

What you’ll build

A calculator service with a single Add method exposed via JSON‑RPC. You can call it over HTTP for simple request/response, and extend it to SSE/WebSocket as you progress.

Continue with the first step: Designing the Service.

In This Section

Designing a JSON‑RPC Service

Learn to design a JSON‑RPC 2.0 service with Goa, including the shared endpoint, method exposure, ID mapping, and transport choices.

Implementing the Service

Generate code and implement a basic JSON‑RPC service in Goa.

Running the Service

Run and call the JSON‑RPC service over HTTP and SSE.