A template to airdrop an ERC-20 token to a group of addresses, while preserving privacy for the claimers.
This repository uses the Semaphore library to allow members of a set to claim an ERC-20 token, preserving their privacy and removing the link between the group and the claimer address thanks to zero-knowledge proofs.
First, you'll need a contract that adheres to the ISemaphore
interface to manage the zero-knowledge groups. If you don't have any special requirements, you can
use this one. Next, you'll need to create a Semaphore group
(Semaphore.createGroup(YOUR_GROUP_ID, 20, 0) should do the trick). You'll also need an address
that holds the tokens to be airdropped (remember to grant access to the airdrop contract after
deployment by calling ERC20.approve(AIRDROP_CONTRACT_ADDRESS, A_VERY_HIGH_NUMBER)). Finally,
deploy the WorldIDAirdrop contract with the Semaphore contract address, the group id, the address
of your ERC20 token, the address of the holder, and the amount of tokens to give to each claimer.
Since only members of a group can claim the airdrop, you'll need to add some entries to your
Semaphore group first. End-users will need to generate an identity commitment (which can be done
through the @zk-kit/identity or
semaphore-rs SDKs). Once they have one, you can add it
to the group by calling Semaphore.addMember(YOUR_GROUP_ID, IDENTITY_COMMITMENT).
Once users have identities included on the configured group, they should generate a nullifier hash
and a proof for it (which can be done through the
@zk-kit/protocols or
semaphore-rs SDKs, using the address who will receive
the tokens as the signal). Once they have both, they can claim the aidrop by calling
WorldIDAirdrop.claim(RECEIVER_ADDRESS, NULLIFIER_HASH, SOLIDITY_ENCODED_PROOF).
You can see the complete flow in action on the WorldIDAirdrop tests.
Worldcoin will maintain a Semaphore instance with a group for all the people that have onboarded to
the protocol. Once the insance is deployed, we'll provide information here so you can point your
WorldIDAirdrop instances to it, ensuring only unique humans can claim your airdrop.
This repository uses the Foundry smart contract toolkit. You
can download the Foundry installer by running curl -L https://foundry.paradigm.xyz | bash, and
then install the latest version by running foundryup on a new terminal window (additional
instructions are available on the Foundry repo).
You'll also need Node.js if you're planning to run the automated tests.
Once you have everything installed, you can run make from the base directory to install all
dependencies, build the smart contracts, and configure the Poseidon Solidity library.
World ID is a protocol that lets you prove a human is doing an action only once without revealing any personal data. Stop bots, stop abuse.
World ID uses a device called the Orb which takes a picture align="center" of a person's iris to verify they are a unique and alive human. The protocol uses Zero-knowledge proofs so no traceable information is ever public.
World ID is meant for on-chain web3 apps, traditional cloud applications, and even IRL verifications.
Regardless of how you landed here, the easiest way to get started with World ID is through the the Dev Portal.
Want to see World ID in action? We have a bunch of Examples.
We have comprehensive docs for World ID at https://id.worldcoin.org/docs.
World ID is in Beta, help us improve! Please share feedback on your experience. You can find us on Discord, look for the #world-id channel. You can also open an issue or a PR directly on this repo.