Architecture Skill

Determine correct file placement and structure for an Electron multi-process project.

Detailed References

Renderer layer (components, hooks, utils, pages, CSS): references/renderer.md
Main process & shared layer (bridges, services, worker, preload): references/process.md
Project root & monorepo layout (directory structure, migration status): references/project-layout.md

Decision Tree — Where Does New Code Go?

Is it UI (React components, hooks, pages)?
  └── YES → packages/desktop/src/renderer/              → see references/renderer.md

Is it an IPC handler responding to renderer calls?
  └── YES → packages/desktop/src/process/bridge/        → see references/process.md

Is it business logic running in the main process?
  └── YES → packages/desktop/src/process/services/      → see references/process.md

Is it an AI platform connection (API client, message protocol)?
  └── YES → packages/desktop/src/process/agent/<platform>/

Is it a background task that runs in a worker thread?
  └── YES → packages/desktop/src/process/worker/

Is it used by BOTH main and renderer processes?
  └── YES → packages/desktop/src/common/

Is it an HTTP/WebSocket endpoint?
  └── YES → packages/desktop/src/process/webserver/

Is it a plugin/extension resolver or loader?
  └── YES → packages/desktop/src/process/extensions/

Is it a messaging channel (Lark, DingTalk, Telegram)?
  └── YES → packages/desktop/src/process/channels/

Process Boundary Rules

Hard rules — violating them causes runtime crashes.

Process	Can use	Cannot use
Main (`packages/desktop/src/process/`)	Node.js, Electron main APIs, `fs`, `path`, `child_process`	DOM APIs (`document`, `window`, React)
Renderer (`packages/desktop/src/renderer/`)	DOM APIs, React, browser APIs	Node.js APIs (`fs`, `path`), Electron main APIs
Worker (`packages/desktop/src/process/worker/`)	Node.js APIs	DOM APIs, Electron APIs
Preload (`packages/desktop/src/preload/`)	`contextBridge`, `ipcRenderer`	DOM manipulation, Node.js `fs`

Cross-process communication:

Main ↔ Renderer: IPC via packages/desktop/src/preload/ + packages/desktop/src/process/bridge/*.ts
Main ↔ Worker: fork protocol via packages/desktop/src/process/worker/WorkerProtocol.ts

// NEVER in renderer
import { something } from '@process/services/foo'; // crashes at runtime

// Use IPC instead
const result = await window.api.someMethod(); // goes through preload

Naming Conventions

Directories

Scope	Convention	Reason
Renderer component/module dirs	PascalCase	React convention — dir name = component name
Everything else	lowercase	Node.js convention
Categorical dirs (everywhere)	lowercase	`components/`, `hooks/`, `utils/`, `services/`
Platform dirs (everywhere)	lowercase	`acp/`, `codex/`, `gemini/` — cross-process consistency

Quick test: "Inside packages/desktop/src/renderer/ AND represents a specific component/feature (not a category)?" → PascalCase. Otherwise → lowercase.

Files

Content	Convention	Examples
React components, classes	PascalCase	`SettingsModal.tsx`, `CronService.ts`
Hooks	camelCase with `use` prefix	`useTheme.ts`, `useCronJobs.ts`
Utilities, helpers	camelCase	`formatDate.ts`, `cronUtils.ts`
Entry points	`index.ts` / `index.tsx`	Required for directory-based modules
Config, types, constants	camelCase	`types.ts`, `constants.ts`
Styles	kebab-case or `Name.module.css`	`chat-layout.css`

Structural Rules

Directory size limit: Max 10 direct children. Split into subdirectories by responsibility when approaching.
No single-file directories: Merge into parent or related directory.
Single file vs directory: If a component needs a private sub-component or hook, convert to a directory with index.tsx.
Page-private first: Start code in pages/<PageName>/. Promote to shared only when a second consumer appears.

Test File Mapping

Tests mirror source files in tests/ subdirectories:

Source	Test
`packages/desktop/src/process/services/CronService.ts`	`tests/unit/cronService.test.ts`
`packages/desktop/src/renderer/hooks/ui/useAutoScroll.ts`	`tests/unit/useAutoScroll.dom.test.ts`
`packages/desktop/src/process/extensions/ExtensionLoader.ts`	`tests/unit/extensions/extensionLoader.test.ts`

When tests/unit/ exceeds 10 direct children, group into subdirectories matching source structure.

architecture