Welcome to Clarity Hack, the first hackathon in the Stacks 2.0 Hackathon Series

A virtual hackathon where you'll build your very own smart contracts using Clarity. The hack will let you experiment and familiarize with Clarity’s developer environment. 

Clarity is Blockstack's smart contract language designed from the ground up to reduce bugs and behave predictably. It provides native functions that make it easy for developers to create complex smart contracts while protecting users at every step. Clarity provides precise tools for enabling on-chain logic while reducing unintentional errors. 

Inspiration: Included is a list of contracts that we'd love to see built (and you're eligible to win bonuses by building one of these), but this is an open-ended contest and you're definitely free to run with your own ideas!

  • Simple exchange
  • DAOs
  • Dapp
  • Counter
  • Supply chain
  • Deeds
  • Access Restriction
  • Withdrawals
  • Send
  • State Machines
  • Balance Address Checker
  • Contracts call another Contract
  • Fundraising
  • Simple Marketplace
  • Basic Provenance
  • Asset transfer
  • Lottery
  • Delegated Voting
  • Smart contract IOT - devices
  • Legal Agreements
  • Payment Splitting


Check out this fantastic list of helpful tools and resources that will give you a headstart with Clarity: https://community.blockstack.org/stacks-series-resources



7/30: Join us for the Stacks 2.0 Hackathon Series kickoff event with Clarity Hack on July 30th. Joe Bender, Blockstack Developer Evangelist, will give you an overview of our different challenges where you can win up to $8,500 in prizes.  Hackers will have the opportunity to win one of our twenty-five prizes! Registration link: https://www.crowdcast.io/e/clarity-hack-workshop 


8/6: Join a Clarity AMA with Stacks Foundation Research Scientist, Jude Nelson on Blockstack's Discord #ask-me-anything channel. Join here: http://discord.gg/QQW67uT 


8/13: Join the Clarity AMA on Blockstack's Discord #ask-me-anything channel. Join here: http://discord.gg/QQW67uT


What is Blockstack? Blockstack is an open-source and developer-friendly platform for building decentralized apps and smart contracts. https://www.blockstack.org/


  • You must build and submit a new contract to be eligible.
  • It will be at the discretion of Blockstack PBC if it is suspected someone is trying to game the system by trying to make slight changes to existing contracts for the reward. 
  • Participants must be at least eighteen years old and may participate individually or form teams.
  • The Hackathon is open to U.S. legal residents and residents of any other jurisdiction where the Hackathon is not prohibited or restricted by law. The Hackathon is not open to residents of Brazil, Quebec, Cuba, Iran, North Korea, Sudan, Syria, or and any jurisdiction where the Hackathon would be restricted or prohibited by law. Participants, including individual participants and members of a team, must be at least 18 years of age (or the local age of majority where they live, if older) at the time of registration.


  • All submitted smart contracts must be open source. The source code should be openly published for modification and use.
  • Contracts must be publicly available on GitHub, Gitlab, or similar publicly accessible link.
  • Contracts must have basic testing and documentation to qualify. 
  • Contracts must be submitted by 11:45 pm EST on August 24, 2020. Late submissions won’t be accepted.
  • Good Will rule: it will be at the discretion of PBC if folks game the system by trying to make slight changes to an existing smart contract for the reward. 
  • Language Requirements: All Submission materials must be in English or, if not in English, the Maker must provide an English translation of the demonstration video, text description, and testing instructions as well as all other materials submitted.

Hackathon Sponsors


$8,150 in prizes

Grande Prize - $2,000

The Grande Prize is $2,000 for best overall contract and a Blockstack swag bag.

Second Place - $1,500

The second place winner will receive $1,500.

Third Place - $1,000

The third place winner will receive $1,000.

Runners Up - $500 (3)

Judges will choose three (3) projects that will receive $500.

Second Runners Up - $250 (4)

Judges will choose four (4) projects that will receive $250.

Third Runners Up - $50 (3)

Judges will choose three (3) projects that will receive $50.

BONUS for the "Smartest" contracts out there! (10)

Now for the cherry on top. Everybody loves some extra credit, so we’ve decided to place a bounty on the head for some of the “smartest” contracts out there. Every blockchain with an SC language should have publicly available a fleet of contracts that fulfill the most basic and necessary functions developers require. The winning entries will receive $100.

Devpost Achievements

Submitting to this hackathon could earn you:


Marvin Janssen

Marvin Janssen
Technical Lead, Stacks Foundation

Jude Nelson

Jude Nelson
Computer Scientist, Stacks Foundation

Judging Criteria

  • Design
    Is the smart contract well-structured, and broken into logical functions?
  • Functionality
    How powerful or robust is the functionality the smart contract provides?
  • Use of Clarity Reference
    How many different Clarity functions, keywords, or design principles are used?
  • Originality / Creativity
    How unique or innovative is the mechanism smart contract? Has it been implemented before?
  • Real World Viability
    How applicable is the smart contract to use in real-world situations?
  • Docomentation / Commenting
    Does the project come accompanied by comprehensive documentation or README? Is the code commented thoroughly so anyone could read through and discern its functionality?

Questions? Email the hackathon manager

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