touchgrass

Problem Statement

touchgrass: Run, Explore, and Mine the Real Worldtouchgrassis a gamified running app that turns outdoor activity into an on-chain data mining experience.When users go out for a run, theystream their GPS coordinates through Yellow Network’s state channels. This live, off-chain stream forms the backbone of a session — allowing real-time location updates, multiplayer awareness, and low-latency gameplay.While running, users can“mine” datacoinsby completingreal-world data quests: spotting potholes, EV chargers, water fountains, or any valuable urban dataset. Each quest represents a small “data job” — when a user submits a photo and proof, the app packages it into aZK-TLS attestation(zero-knowledge time-location proof) and sends it to the backend for validation. A lightweightLLM validatorchecks the submission (e.g., “is this really a pothole?”) and confirms the claim’s accuracy.If the data is valid, the event is emitted through Yellow’s state channel as adatacoin capture, and the runner is rewarded with a minteddatacoinNFT — representing a verifiable, user-contributed data point anchored to the real world.When the user pressesSTOP, the session closes:Thefinal state(distance, route, and validated datacoin captures) issettled on-chainvia Yellow’s channel settlement.The datacoins mined during the session become claimable on-chain assets, each tied to a verifiable proof of work (running + data capture).On the frontend, aMapbox-powered interfacevisualizes everything live:active runners around you (via Yellow’s real-time state feed)datacoin markers appearing as users mine real-world dataa leaderboard that aggregates who has contributed the most verified dataUnder the hood:Next.js web appfor frontendYellow Network state channelsfor real-time GPS streaming and off-chain state consensusLLM validator servicefor automatic data quality checksZK-TLS proofsfor privacy-preserving location attestationDatacoin smart contractfor on-chain minting and reward settlementMongoDBfor persistence (runs, users, datacoins, proofs)Why this matterstouchgrass transforms outdoor movement into a decentralized sensing network. Instead of mining digital blocks, runnersmine physical data— building an open, verified map of real-world insights: where potholes exist, where clean water points are, where EV chargers work. Every step becomes a datapoint, and every verified submission turns into a tokenized contribution to a collective data layer.In short:touchgrassbridgesmovement,data provenance, anddecentralized rewards— powered byYellow’s state channelsfor real-time off-chain interaction and on-chain finality.

Solution

touchgrass is built as aNext.js web appthat usesYellow Network state channelsto stream real-world movement data andLighthouse’s Datacoin SDKto mint verifiable, rewardable consumer data assets.When a runner hitsSTART, their GPS coordinates begin streaming through aYellow clearnet state channelto our backend peer. This off-chain state channel provides a low-latency, verifiable stream of location updates while keeping everything off-chain until the session ends. The backend aggregates those updates, anchors them inMongoDB, and broadcasts live map changes to nearby players in real time.While running, users can completedata quests— such as mapping potholes, EV chargers, or water fountains. When a user submits a photo, the backend usesReclaim Protocol’s zkTLS proofsto attest to location and time without revealing sensitive GPS data. We then run a lightweightLLM-based validatorto verify the content of the submission (for example, confirming that the image truly contains a pothole).If the data is valid, we mint aDatacoinusing theLighthouse SDK— encoding the data’s proof, metadata, and contributor wallet into a verifiable token on-chain. Each Datacoin represents a useful, privacy-preserving, user-contributed data point that can be queried or traded later as part of an open data economy.When the runner pressesSTOP, the Yellow state channel finalizes the session:the off-chain state (distance, movement, mined datacoins) issettled on-chain,rewards are distributed to the user’s wallet,and the data contributions are finalized via Lighthouse’s Datacoin protocol.The frontend usesMapbox GL JSfor live visualization — showing nearby runners, mined datacoins, and verified quest markers — while the backend (Node + MongoDB) maintains persistent state and proof data. We also added aJS-based lat/lon bucketing systemto map territory and manage channel routing efficiently across the world.Stack summary:Next.jsfor the web app UIYellow Networkfor off-chain state channels and realtime GPS syncLighthouse SDKfor Datacoin mintingReclaim Protocol + zkTLSfor privacy-preserving proof-of-locationLLM Validatorfor content validationMongoDBfor persistenceMapbox GL JSfor the live interactive mapNotable hack:We cached Mapbox tile hashes locally to generate deterministic zkTLS proofs quickly, allowing near real-time Datacoin minting from field data without repeated external API calls.