SimpleChatJS

An Electron desktop AI chat application with MCP (Model Context Protocol) support.

Tech Stack

• Frontend: Vanilla JS, HTML, CSS (no frameworks)
• Backend: Node.js + Express
• Desktop: Electron
• Database: SQLite (better-sqlite3)
• MCP: @modelcontextprotocol/sdk

Features

• Multiple persistent chat sessions with SQLite storage
• Real-time streaming responses from AI providers
• Model Context Protocol (MCP) integration for tool execution
• Chat branching and turn-based history
• Multimodal messages (images, documents)
• Debug panels with API request/response inspection
• Settings profiles for different AI providers
• Anthropic thinking mode and Google Gemini thinking support

Quick Start

Prerequisites

• Node.js
• An AI API (Ollama, OpenAI, or any OpenAI-compatible endpoint)
• Linux: FUSE (required to run the AppImage)

Installation

npm install
npm run dev

Build

npm install
npx electron-builder install-app-deps
npm run build

Output goes to `dist-electron/`.

Architecture

src/js/
├── app/          # Core logic (message sending, API calls, settings)
├── chat/         # Chat modes and history management
├── tools/        # MCP server management and tool handling
├── render/       # Message rendering and streaming
└── ui/           # Settings, debug panels, context menus

backend/
├── server.js           # Express server (runs inside Electron)
├── config/             # Database initialization
├── routes/             # API endpoints
├── services/           # Chat, MCP, settings, tool events
└── utils/              # Logging

API Compatibility

Works with any OpenAI-compatible API:

• Ollama - Local AI models
• OpenAI API - GPT models
• Anthropic - Claude (via proxy or direct)
• Google Gemini - Gemini models
• LM Studio / vLLM - Local inference servers

CI/CD

Pushes to `main` trigger automated builds via GitHub Actions:

• Build job: Runs on Windows, Linux, and macOS in parallel. Produces distributable packages (`.zip`, `.AppImage`, `.dmg`).
• Release job: Triggers only when the version in `package.json` differs from the latest git tag. Creates a draft GitHub Release with all platform builds attached.

Development

• Edit files in `src/js/` or `backend/`
• Reload the app (Ctrl+R) for frontend changes
• Restart the app for backend changes