Shunkan
Clipboard and file sync with no cloud
瞬間 — an instant. Nothing leaves the room.
Rust · quinn QUIC · rustls · SPAKE2 · BLAKE3 · UniFFI · Tauri v2ISubjectWho it was for
Two devices on the same Wi-Fi that could only reach each other through someone else's server.
IIPresenting symptomThe problem
Every clipboard-sync tool either routes your clipboard through a vendor's cloud or assumes you live inside one vendor's ecosystem.
IIIReconstructionWhat was really going on
Nothing about copying text from a laptop to a phone needs the internet. Discovery, trust and transport can all stay on the local network, if pairing is done properly.
IVInterventionWhat I built
- 01
A shared Rust core finds peers over mDNS and talks QUIC (quinn over rustls) with self-signed TLS.
- 02
Devices pair with a SPAKE2 PIN bound to both certificate fingerprints, then pin each other in a trust store.
- 03
Clipboard history is BLAKE3-deduplicated; files move as chunks reassembled by index, tracking what is missing.
- 04
Android gets a keyboard, a quick-settings tile and a share target through UniFFI; the desktop side is a Tauri v2 app.
VEvidenceResults
- 222
- tests
- 203 unit, 19 async/integration
- 20 MB
- idle RAM ceiling
- a design rule, not a measurement
- 2
- clients: Android and Linux
VILimitationsWhat it doesn't do
- Not packaged for end users yet.
- Same local network only. There is no relay, by design.
- The 20 MB figure is a design ceiling, not a benchmark.
- Not yet licensed for reuse.
VIIExhibitsLinks
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