Saul Garcia

Grass

Jun 2025

ETHGlobal Prague

Fitness verification platform using zkTLS to turn activity into onchain achievements.

overview

Grass turns real-world activity into verified onchain achievements.

It combines health tracking, social challenges, and incentives while using zero knowledge to verify fitness data without exposing sensitive metrics.

how it was made

  • zkTLS verifies real fitness data from web sources.
  • vlayer SDK handles private web proof verification.
  • Smart contracts manage bets, user profiles, communities, and settlement on Ethereum.

awards

  • vlayer - Best use of Web Proofs
  • Blockscout - Big Blockscout Explorer Pool Prize
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