Cobalt

What it does

Cobalt is an open-source app platform for Kobo e-readers: a launcher, a signed App Store, a Rust SDK, and a capability-isolated runtime. One USB install; every app after that arrives over Wi-Fi.

Install useful apps on a supported Kobo e-reader. Set up Cobalt once over USB, then add, update, and remove apps over Wi-Fi.

Cobalt is an open-source application platform for Kobo e-readers: a launcher, a signed apps catalog, a Rust SDK, and a runtime that keeps every app in its own unprivileged process. Read books and papers, follow feeds, play a game, listen to audio, or check a task without changing devices. Install only the apps you want, then update or remove them over Wi-Fi. These are the Kobos somebody has physically tested. Cobalt runs on others too: it shows what has not been tested about your device and asks once before it starts. To get yours onto this list, join an existing device thread or create a new one . Cobalt adds apps next to the stock reader. Your books, library and reading settings are left…from bandarlabs.github.io

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  Hey HN, I built an SDK to help me create apps I wanted on my Kobo. My Kobo device has a single core <1GHz processor and 512MB RAM, much less than a Raspberry Pi, but the eInk display and larger battery life opens up a lot of use cases. I have since used it to build an approval sidekick for my Mac's Claude code and codex, a Hacker News Client for Kobo, a Gutenberg reader, an RSS search and reader and more. All the code is in the repo. If you have a different device than mine (Clara BW) would love for you to test it on your device and submit a PR to enable this for more device profiles. Thanks.

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