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M5Stack CoreS3 running Reflect, plugged in over USB-C
M5Stack CoreS3 running Reflect, plugged in over USB-CCredit: openai/openai-reflect (MIT)

Reflect: a voice-and-light assistant on an M5Stack CoreS3

Gadget, Medium

An OpenAI hackathon project: an M5Stack CoreS3 talks to the Realtime API and answers with sound and colored light from a LIFX bulb. Your phone holds all the state.

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Reflect was built during an OpenAI hackathon and is published as-is. The goal was a cheap assistant that talks through sound, light and color instead of a screen. The device stores nothing, and your phone is the key. Example uses from the README include asking about yesterday's calendar events, getting ready for a test tomorrow, and playing music while you study.

It runs on an M5Stack CoreS3 with a LIFX Color A19 bulb. You build with ESP-IDF v5.5 and flash it. The device then opens a Wi-Fi access point called reflect, and you start a session at 192.168.4.1 from your phone. MIT licensed. The README warns it hasn't been reviewed for security or reliability.

How your agent drives it

Copied from the openai/openai-reflect README

  1. Shell
    $ ./install.sh esp32s3
  2. Shell
    $ idf.py flash

Any coding agent that can run a shell can run these. Read the README before you run anything on a robot that moves.

Ideas to try with it

Our ideas, not the builder's claims.

  1. Have the light turn amber when your robot needs attention
  2. Ask it what's on tomorrow's calendar before bed
  3. Swap the bulb for an LED strip on a desk robot
Source
openai/openai-reflect on GitHub
Last commit
2026-03-27
Builder
openai
Repo
openai/openai-reflect, 200 stars
Built with
M5Stack, ESP32-S3

Links

Guides: Codex and ChatGPT hardware projects people actually built · AI hardware for robot and agent builds

What to build next

Builds that share a board, robot or agent with this one.