Why I Abandoned Electron & SPAs to Build a 128MB Local-First Desktop AI Agent

How the ERTH Architecture (ElectroBun + Robyn + Turso + HTMX) breaks the obesity of modern desktop app development. If you’ve tried to build a cross-platform desktop application recently, you’ve likely faced the classic developer’s dilemma: Electron makes developer velocity fast, but at the cost of dragging a bloated Chromium kernel and Node.js runtime into every build. A simple "Hello World" easily eats up 200MB+ of disk space and hundreds of megabytes of RAM. Tauri solves the footprint issue by using OS-native WebViews and Rust, but forces you onto Rust’s steep learning curve, sacrificing the agility of rapid prototyping. The Python Distribution Hell : With the rise of local LLMs and Edge AI, Python is the de facto language for AI orchestration. Yet, packaging Python, its heavy dependencies, and databases into a double-click-to-run package for non-technical users remains a nightmare. Faced with these shackles, I decided to take a step back and rewrite the physical laws of desktop development. Today, I’m introducing the ERTH Stack ( E lectroBun + R obyn + T urso + H TMX)—a heterogeneous, local-first, zero-JS desktop application architecture designed for independent full-stack creators. And yes, the entire bundle—including a browser shell, a high-performance Python sidecar, a local database, and local AI agent execution—packages into a single 128MB standalone binary. Our open-source implementation is live on GitHub: 👉 GitHub Repository: bnpysse/erth_assistant The Core Pillars of the ERTH Architecture To achieve a minimalist footprint without sacrificing developer velocity, we structured the architecture into four core layers: ERTH ARCHITECTURE [E]lectroBun (UI Shell) ───[HTMX]───► [H]TMX (Zero-JS Frontend) │ ▲ (IPC) (HTTP) ▼ │ [R]obyn (Python Sidecar) ───────────► [T]urso / libSQL (Local-First DB) 1. [E]lectroBun: The Lightweight Shell Instead of Electron’s heavy Chromium, ElectroBun binds directly to the OS-native WebKit engine (Cocoa WebKit on macOS, WebView2 on W