I think Tom Riddle’s diary from Harry Potter was both a magical diary and a Horcrux. Tom Riddle experimented with every kind of dark magic, so a diary that writes back feels right at home in his collection. Developer Maxime Rivest recreated that idea by hacking the reMarkable Paper Pro E Ink tablet into a diary that answers handwritten questions with help from AI. He shared the demo on X on July 5, and it has since topped 2 million views. So what’s Rivest’s trick? (Assuming he isn’t also using Horcrux magic.)
You write a question by hand, the tablet recognizes the handwriting, sends it to an AI model, erases the ink, and animates a reply onto the same page. Rivest, who posts as @MaximeRivest, credited the response generation to Fable, and by July 6 he’d published a work-in-progress GitHub repo called “Riddle” for anyone comfortable with Linux and SSH to try it themselves. He said a beginner-friendly version is coming once he’s confident the setup won’t trip people up.
None of Rivest’s tricks works without a setting most reMarkable owners never touch. Rivest explained in a reply to podcaster Matthew Berman that the tablet has a developer mode that turns it into, in his words, “a Linux box with a special display and inputs channel.” Once that’s flipped on, he lets coding agents connect to the device over SSH to experiment.
That’s a meaningful detail for anyone who owns a reMarkable and didn’t realize the hardware was this open. The tablets are built on a monochrome E Ink display and a fairly modest processor, not exactly a platform you’d associate with running AI-triggered animations. But the developer-mode access apparently gives Rivest enough control over input and display to intercept handwriting and redraw the screen programmatically, which is what makes the fading-and-reappearing text trick possible.
Rivest’s other reply, a quip about needing to put “Claude code into it now,” comes across as a joke about extending the project rather than a concrete announcement, and nothing in the thread confirms a specific next integration beyond that.
From diary to dictation: the voice app follow-up
After the original post, Rivest shared a second build, an Android app that turns a phone into a microphone for the E Ink tablet. The setup lets him dictate text before editing it by hand on the tablet’s paper-like surface. He said the app was made with “gpt-5.6-sol” and that combining voice input with pen-and-paper editing produced a writing feel he described as special.
This one comes with no Harry Potter framing, and Rivest was upfront about that shift. He said the wider goal behind both projects is a bet that pairing E Ink displays with AI can produce a meaningfully better form of human-computer interaction than what’s on phones and laptops today. Two very different demos, a diary that talks back and a voice-to-page dictation tool, both point at the same underlying thesis rather than a single product he’s building toward.
Rivest’s hobby project arrives right as reMarkable itself has been adding AI to its lineup. The company’s Paper Pure tablet already ships with AI-assisted meeting notes that pull agenda details from calendar invites and summarize action items afterward. In addition, a bunch of digital notebooks, including reMarkable’s, now use AI to convert handwriting into text. Amazon’s competing Kindle Scribe goes further with a built-in AI chatbot for querying notes and books.
None of the official reMarkable AI features work the way Rivest’s hack does, though. The company’s tools operate within the interface reMarkable ships, generating summaries or transcriptions the user requests. Rivest’s version hijacks the writing surface itself, erasing what the user wrote and replacing it with generated text designed to look like the tablet is responding unprompted. That’s a fair distance past a productivity feature and closer to the kind of ambient-AI experiment that developer-mode tinkering makes possible on hardware not designed for it.
Before you go
Rivest’s GitHub repo is a work in progress, and he hasn’t said when a wider, beginner-friendly release might arrive. The X thread doesn’t specify what the actual round-trip latency looks like between writing a question and getting an animated reply or how reliably the handwriting recognition holds up outside a demo clip.
It’s also worth noting that turning on developer mode is the kind of step that can affect your device’s warranty, something neither Rivest’s posts nor the coverage around them address.
We [at reMarkable] reserve the right to not provide support to software that has been subject to such changes or modifications. Errors or defects resulting from changes or modifications made by you will not be covered by our Limited Warranty or Protection Plan, or any legal warranty you might have (to the extent permitted under applicable law). reMarkable disclaims all liability in that regard.
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Grigor Baklajyan is a copywriter covering technology at Gadget Flow. His contributions include product reviews, buying guides, how-to articles, and more.