• Claude Code and Codex credentials are read only by the Neon Meter app.
• The renderer receives only sanitized usage payloads over IPC.
• Settings persistence stores locale, sync interval, display rotation interval, and auto-sync state.
• Do not add credential form fields to the renderer.

• Electron uses native main-process USB serial and BLE for reconnects and writes. The renderer only calls the preload bridge and does not receive native device handles.
• USB serial connects only after the firmware answers the neon-meter-usb hello frame. Non-JSON serial logs and unknown JSON frames are ignored.
• Native BLE connects only to devices matching the Neon Meter name prefix, the legacy AI Meter prefix, the remembered local device ID/name, or the firmware service UUID.
• Web Bluetooth remains a static-preview fallback when native BLE is unavailable.
• Payloads contain percentages, reset times, status, and compact text only.
• Device writes are initiated by the local user or the local auto-sync timer.

• contextIsolation is enabled.
• nodeIntegration is disabled in the renderer.
• The preload bridge exposes only metadata, settings, provider bundle fetch, and device control calls.

Provider network requests are made from the Neon Meter app:

• Claude Code: https://api.anthropic.com/v1/messages
• ChatGPT/Codex: https://chatgpt.com/backend-api/wham/usage