Congratulations to the ETHDenver 2021 Hackathon Chainlink Bounty Winners

The Spring 2021 Chainlink Virtual Hackathon is underway! Sign up today to compete for $125k+ in prizes.

We’re happy to announce the Chainlink bounty winners for the 2021 ETHDenver Hackathon. These projects showcased unique smart contract functionalities using Chainlink’s oracle network in a wide variety of ways, including calling off-chain APIs for GitHub repos, municipal property ownership records, and NBA player performance data. Winning projects also used Chainlink VRF for provably fair on-chain randomization of NFT attributes and gamified ticketing systems. This cohort of winners is a testament to the expansive array of use cases that Chainlink enables beyond the network’s already widely-adopted price feeds.

We awarded projects a total of $5,000 in prizes, with $1,000 to four top projects, and $500 to two runner-up projects. Each ETHDenver hackathon project used Chainlink oracles to securely connect Ethereum smart contracts to off-chain data and resources. We hope these hackathon prizes encourage these teams and more across the ecosystem to continue exploring the broad capabilities of Chainlink-powered smart contracts.

Thank you to all the participants, sponsors, and judges at ETHDenver’s 2021 Hackathon for coming together to #BuildwithChainlink and enabling another burst of innovation around universally connected new smart contract applications.

The winners below are highlighted in alphabetical order.

Crypto Plants

Crypto Plants rewards philanthropic cryptocurrency donors with unique NFTs to encourage social sharing and social good. Developers Shardul and Daksha Aeer built a dApp that allows users to select a charity, pay in ETH, then receive an NFT featuring a potted plant. The project uses Chainlink oracles to make an API call and fetch the NFT metadata including the plant image, description, types, and other elements on-chain. This is a great example of using Chainlink oracles to power provably rare and dynamic NFTs that react to external data inputs, a key functionality in the rapidly growing NFT landscape.

The goal of Crypto Plants is to encourage environmentally and socially conscious giving, using the benefits of digital scarcity to reward donors with verifiably unique digital status symbols.

Identity Lego Starter Set

Developers Graven Prest, Cody Hatfield, Will Holcomb, and Erik Seglem created the Identity Lego Starter Set, composable identity components that on-chain services can use to build a custom set of user identification requirements. This proof of concept focused on Colorado ID systems and allows smart contracts to trigger events based on an approved matching of ID sources to data such as an Ethereum wallet address or physical address.

The Identity Lego Starter Set leverages Chainlink oracles to verify whether a user owns a parcel of real estate property in the Denver area according to municipal records. The project uses a Chainlink External Adapter to access publicly available data and an exact name match, allowing the smart contract to compare the data to the user’s digital ID credentials. The Starter Set is another compelling example of how projects are leveraging Chainlink’s tamper-proof oracle network to securely fetch external data for blockchain-based D-ID solutions.


In the pr!ce project, developers Anweshi Anavadya, Ishan Ghimire, Sam Orend, and Jasraj Bedi built a competitive trading platform that can be used to earn rewards for high-performing assets. For this proof of concept, the pr!ce team issued tokens that represent NBA players as tradable assets and used Chainlink oracles to call off-chain NBA player data to determine performance metrics. pr!ce can best be understood as a blockchain-based fantasy sports model, but can also be applied to other zero-sum performance assets such as volume data, voting, and other rank-based metrics.

Using ETH, users purchase shares of a given asset as an ERC-1155 semi-fungible token (SFT), in this case an NBA player. Then pr!ce uses Chainlink to call player performance data to determine which players had higher performance success in a given week. The smart contract then distributes ETH rewards to shareholders with top-performing players. At the end of the season, the user with the highest amount of shares for a given player receives a unique player NFT as a trophy and has the option to donate to a charity with the proceeds from pr!ce protocol fees.


Developer team TruCol, composed of Victoria Bosch, Marc Droogh, Kirina van der Bijl, and Akke Toeter, created a bounty-fulfilling smart contract platform for test-driven programming in a trust-minimized development environment. A user posts a test and bounty on the platform with technical specifications indicated in the smart contract, and when a bounty hunter fulfills the specifications, the smart contract pays out the bounty.

TruCol suggests using this platform as a test environment for prospective job applicants, where an employer posts code for problems and solutions in the smart contract and selects bounty hunter applicants who provide correct solutions. TruCol uses Chainlink VRF to securely randomize the problem-solution set that the bounty hunter receives, preventing anyone from gaming the test system and giving each bounty hunter a provably fair assignment. Another implementation of the platform uses Chainlink oracles to read a given GitHub repository API to detect a continuous integration in the repository, so bounty hunters can submit code through a pull request and any merged changes trigger the smart contract to pay the bounty.


Runner-Up Prizes

The DaoMV

The DaoMV used Chainlink VRF to create randomization for ID numbers.


Unirace used Chainlink VRF to select a random winner in a virtual race using NFT tickets.

Congratulations winners, and thank you to all the developers who used Chainlink in the ETHDenver 2021 Hackathon. We’re always excited to see our community extend the capabilities of the Ethereum ecosystem using Chainlink’s decentralized oracle network.

The Spring 2021 Chainlink Virtual Hackathon is officially underway, so make sure you sign up today to participate in our biggest hackathon yet. The hackathon is a great opportunity to level up your smart contract development with Chainlink, learn from top teams in the space, and compete for over $125k in prizes. Registration will remain open until the hackathon midway point, so sign up today to secure your spot.

If you’re a developer and you need resources to get your application connected to Chainlink Price Feeds, Chainlink VRF, or to access any API, visit the developer documentation and join the technical discussion in Discord. If you want to schedule a call to discuss the integration more in-depth, reach out here.

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