The riddle project turns a reMarkable Paper Pro into a live diary particle. Developers enable the tablet’s developer mode with remagic, which installs a custom App Load bundle that runs the diary as root. The interface skips any GUI; the user writes with a pen, the page erases the ink, and a vision LLM reads the PNG snapshot, streams a reply stroke by stroke, and then lets the ink fade.

The core stack is written in Rust. Pen input flows through raw evdev events with 4096‑level pressure, commits the page to PNG, and then hands it to an Oracle process that calls a vision‑capable model. Two backends exist: a direct OpenAI‑compatible API (default gpt‑4o‑mini) or a local pi node that keeps the model warm. Rendering occurs in two modes: a windowed qtfb inside the vendor UI, and a full takeover quill that stops the original e‑ink engine and drives the display directly, achieving ~0.9–1.1 s latency to first ink.

Building is cross‑compiled to aarch64. Users may download a prebuilt zip, unzip to /home/root/xovi/exthome/appload, or use remagic to install. The app manipulates the device at the system level, requiring root privileges and disabling the stock UI, so SSH access must be preserved as a safety exit.

Practical use cases include low‑power note‑taking with AI augmentation, instant feedback for handwriting training, and a prototype for e‑ink‑based interactive assistants. The tight integration of hardware event handling,bn the LLM pipeline, and the takeover mode shows how thin‑client devices can host sophisticated AI workflows without sacrificing battery life or display quality.