AlphaBits Venture Partner

Second Brains OS

A workspace for personal and team productivity that runs in one browser tab. Workspaces, kanban boards, a calendar, notes and an AI chat open as windows you can drag around the screen. The web app is in open beta at secondbrains.xyz, and companion desk devices built on the ESP32-S3 are planned for Q4 2026.

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01 · The problem

Productivity tools live in separate tabs

Most people keep their to-do lists, notes, calendars and AI assistants in different apps. Each switch between them costs a little attention, and over a working day that adds up.

02 · What we built

One desktop-style shell in the browser

Second Brains OS puts those tools in a single shell. Each one opens as a window you can move and stack, and a server monitor and markdown editor sit next to the planning tools.

The same server connects to small desk devices over MQTT and to the browser over WebSockets, which is how the hardware will share state with the web app.

Where it stands

FreeEvery feature is free during the open beta, with at least 30 days' notice before any charges.
Q4 2026Planned launch for the ESP32-S3 desk devices.
VoiceGroq Whisper transcribes speech, Llama 3.1 8B answers and Orpheus reads the reply aloud.
1 tabEvery window runs inside a single browser tab.

Desk hardware

Interactive namecards

ESP32-S3 boards running Rust firmware, with a 1.83-inch LCD and physical buttons. The first designs show power and server stats. Transparent OLED, e-ink and solar versions are planned after that.

Intercom bridge

An ESP32 companion that connects a Comelit 6802W intercom to Wi-Fi and Home Assistant. It is still an R&D project.

System architecture

Desk devices ESP32-S3, Rust firmware Planned for Q4 2026 MQTT client MQTT Server Bun and Hono SQLite with Drizzle Groq voice pipeline WebSockets Browser shell Vanilla JS components Window manager Draggable windows

Why one stack matters

A product that pairs hardware with software usually needs separate teams for the mobile app, the web app and the firmware, and keeping them in step slows everyone down.

Second Brains OS keeps the server, the browser shell and the device messaging in one TypeScript codebase on Bun, so one change can reach all of them. Web updates go live without waiting for an app-store review. The firmware is the one separate piece, written in Rust.

Technical details

Server
Bun runtime, Hono, WebSockets
Database
SQLite with Drizzle ORM
Browser shell
Vanilla JavaScript custom elements with a window manager
Device messaging
MQTT, connected to an external broker
Firmware
Rust (esp-hal and Embassy) on ESP32-S3
Display
1.83-inch ST7789P LCD
Voice
16 kHz mono microphone capture; Groq Whisper, Llama 3.1 8B and Orpheus TTS

Open beta

Try Second Brains OS

The web workspace is live at secondbrains.xyz, and every feature is free during the beta.

Visit secondbrains.xyz ↗← Back to Venture Partners