An ESP32-C3 Super Mini device with a 1.54" ST7789 TFT display that tracks AI token/credit usage across multiple providers — Claude Code, Cursor, Codex, GPT/OpenAI, and DeepSeek — right on your desk.
WiFi is configured via a captive portal; you add agents and API keys through a browser UI; the device polls provider APIs autonomously every 10 minutes and shows live usage on its screen.
- 📶 Captive-portal WiFi setup — no hardcoded credentials, connect from any phone/laptop on first boot.
- 🖥️ Web UI — add/remove agents, paste API keys, pick a probe model, all from the browser (served directly off the device).
- 🔄 Autonomous polling — fetches usage every 10 minutes with no PC required, for providers that support an on-device API key.
- 📊 Adaptive display — shows whatever data is available: progress bar
- token count, raw token count, or account balance.
- 🌉 Companion bridge script (
tools/usage-daemon.py) for providers whose auth can't be typed into the device directly — Claude Code's local OAuth session and Codex CLI's local login — plus Cursor IDE's local token. The web UI generates the exact command to run (device IP, agent slot index) — just copy and paste. Its push interval is set live from the web UI's "Update every (sec)" field and re-read every cycle, so changing it takes effect without restarting the script. ⚠️ Daemon-staleness warning — if the companion script stops running, the device notices (no push within the expected interval) and shows "Start the daemon for fresh data" on both the TFT and web UI instead of silently going stale.
- ESP32-C3 Super Mini -> https://www.aliexpress.com/i/1005005319963906.html
- 1.54" ST7789 240×240 TFT display -> https://shorturl.at/lCPbd
- 3d print -> https://www.thingiverse.com/thing:7380035
- Pin mapping (see
platformio.ini): SCLK=4, MOSI=6, CS=7, DC=2, RST=3, BL=8
4-wire SPI, write-only (no MISO needed). Pin numbers are ESP32-C3 GPIOs, as
defined in include/config.h:
| ST7789 pin | ESP32-C3 pin | GPIO |
|---|---|---|
| VCC | 3.3V | — |
| GND | GND | — |
| SCL/SCLK | GPIO4 | 4 |
| SDA/MOSI | GPIO6 | 6 |
| CS | GPIO7 | 7 |
| DC | GPIO2 | 2 |
| RES/RST | GPIO3 | 3 |
| BLK | GPIO8 | 8 |
ESP32-C3 Super Mini ST7789 1.54" TFT
┌─────────────────┐ ┌─────────────────┐
│ 3.3V ──┼──────────────┼── VCC │
│ GND ──┼──────────────┼── GND │
│ GPIO4 ──┼──────────────┼── SCL (SCLK) │
│ GPIO6 ──┼──────────────┼── SDA (MOSI) │
│ GPIO7 ──┼──────────────┼── CS │
│ GPIO2 ──┼──────────────┼── DC │
│ GPIO3 ──┼──────────────┼── RES (RST) │
│ GPIO8 ──┼──────────────┼── BLK │
└─────────────────┘ └─────────────────┘
# Build firmware
pio run
# Build + upload to ESP32
pio run --target upload
# Upload web UI files (SPIFFS filesystem)
pio run --target uploadfs
# Build + upload + open serial monitor
pio run --target upload && pio device monitorOn first boot the device opens a WiFi setup portal — connect to it, pick your network, and it reboots into the main web UI. From there, add an agent per provider and paste an API key (where applicable).
For Claude Code / Codex / Cursor, add the agent with the API key field left empty, then run the companion script on your PC to push usage (the web UI's agent card shows this exact command, pre-filled with your device IP and agent slot):
python tools/usage-daemon.py --push claude:0Its push interval is controlled live from the web UI's "Update every
(sec)" field — no need to restart the script after changing it. Full setup
(model filters, multiple providers, bridge mode) in
tools/README.md.
A Playwright suite covers the web dashboard and REST API, running against
either an auto-started mock (no hardware needed) or the real device. See
tests/README.md.
See CLAUDE.md for the full architecture breakdown (firmware
modules, HTTP protocol, storage layout, display render logic).