erpc-communication

name	erpc-communication
description	Guides using eRPC (electron-tRPC) for inter-process communication (IPC) between Electron main and renderer processes. Triggered when handling Electron IPC or tRPC-based systems.

eRPC Communication Guide

This skill provides mandatory instructions for implementing type-safe IPC using eRPC in this project.

1. Main Process Implementation

• Route Definition: Must use the project's provided router utility to define tRPC routes.
• Handler Initialization: Must use createIPCHandler from erpc/main to bind the router to Electron windows.
• Context Injection: Should provide necessary instances (e.g., BrowserWindow or Tray) through createContext.

// Always initialize createIPCHandler within the app ready lifecycle
import { createIPCHandler } from 'erpc/main'

import { routers } from './rpcs'

createIPCHandler({
	createContext: async () => ({ win: mainWindow, tray: appTray }),
	router: routers,
	windows: [mainWindow]
})

2. Preload Script Configuration

• Expose Bridge Interface: Must call exposeElectronTRPC() provided by erpc/main in the preload script.
• Lifecycle: Should be called inside process.once('loaded').

import { exposeElectronTRPC } from 'erpc/main'

process.once('loaded', () => {
	exposeElectronTRPC()
})

3. Renderer Process Usage

• Client Creation: Create tRPC client using ipcLink from erpc/renderer.
• Type Safety: Always import Router type from main process to ensure complete end-to-end type safety.

import { createTRPCClient } from '@trpc/client'
import { ipcLink } from 'erpc/renderer'

import type { Router } from '@desktop/rpcs' // Import Router type from main process

export const trpc = createTRPCClient<Router>({
	links: [ipcLink()]
})

4. Routes and Endpoints Best Practices

• Single Responsibility: Each route should correspond to a specific service in the main process (e.g., window, file, dialog).
• Parameter Validation: It is strictly prohibited to write complex business logic in Router. Router is only responsible for validating input and output parameters; business logic must be delegated to Service (e.g., calling WindowService.open()).
• Type Reference: For complex object parameters, type definitions must be placed under the packages/erpc package and shared between both ends, avoiding direct cross-package imports of entity logic.