Light and Sound Show is a media-native signed action layer for short-form video. Instead of asking a creator to put a visible QR code on a reel, LSS embeds a compact signed payload into the media itself and lets a reader recover that payload from repeated visual and audio observations.
The product shape is intentionally small: create a signed action, carry it through ordinary media, recover it with a reader, and resolve it only after verification.
Builder map
The monorepo has a small core plus supporting packages:
@lss/protocolowns canonical payloads, signatures, fragmentation, checksums, and reconstruction data structures.@lss/embedderturns fragment strings into deterministic visual frame plans and ultrasonic tone plans.@lss/readercurrently provides deterministic simulated read behavior over protocol candidate fragments.@lss/resolverassumes a signed payload has already been verified, then maps known payload bodies into demo action results.@lss/dbstores issuer public keys and issuer status for app-side verification flows.@lss/loggerprovides redacted structured logging.@lss/uiis currently an empty shared UI placeholder.@lss/webis the demo surface for creator, reader, ticket, deck, and prototype workflows.
What LSS protects
LSS protects authenticity, not secrecy. A decoded payload is readable by design. Today, @lss/protocol can verify Ed25519 signatures, reject corrupt fragments by checksum, and reconstruct complete or single-missing-fragment messages with XOR parity. Expiry and issuer policy are carried in the payload and supporting packages, but callers must enforce them before treating a resolver result as trusted.
Best fit
Use LSS when the interaction begins with a video and the action should travel with that video through sharing, replay, projection, or screen recording. Use QR for signage, NFC for tap cards, BLE for nearby radio presence, and watermarking or fingerprinting when identification is more important than carrying an action payload.