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Campaign Verification on Etherscan

When the airdrop campaign contract is deployed for the first time on a chain, the source code has to be verified to make it public and viewable on Etherscan. This guide will walk you through the process of verifying the campaign contract on Etherscan. If you get stuck, you can ask for help on Discord.

As an example, we will use the SablierMerkleLL contract deployed on Arbitrum Sepolia at 0x0ef0647b7324238bfa6084b54ad2d4fd58d8e4ef.

Good to Know

Since Etherscan automatically verifies the contracts based on the matching source code criterion, this verification is only required once per chain.

Step 1: Identify the transaction hash​

Find the transaction that created the contract. For our example, this is the transaction.

Step 2: Identify the function name​

On the transaction page, locate the "Click to show more" button, and click it:

Campaign Verification 01

In this case, the function name is createMerkleLL. Then, locate and note down the function name.

Campaign Verification 02

Step 3: Copy the input data and campaign creator address​

Click on the "View Input As" button, then change the view to "Original", and copy the input data.

Campaign Verification 03_1

Copy the address of the campaign creator from the "From" field.

Campaign Verification 03_2

Step 4: Get the constructor argument​

Go to SablierMerkleAirdropDecoder and make sure you are on the "Read Contract" section.

  1. Click on decodeMerkleInstantArgs if the function name from step 1 is createMerkleInstant.
  2. Click on decodeMerkleLLArgs if the function name from step 1 is createMerkleLL.
  3. Click on decodeMerkleLTArgs if the function name from step 1 is createMerkleLT.

In this case, since the function name was createMerkleLL, we will click on decodeMerkleLLArgs.

  • In the txData (bytes) field, paste the input data copied from Step 2.
  • In the campaignCreator (address) field, paste the campaign creator address copied from Step 2.

Click on the "Query" button and copy the output, which is also the constructor argument of the campaign contract.

Campaign Verification 04

Step 5: Build the contracts​

Clone the sablier-labs/airdrops repo, and build the contracts from the release branch. Note that you will need Foundry installed for this.

git clone git@github.com:sablier-labs/airdrops.git
git switch release
bun install --frozen-lockfile
bun run build:optimized

Step 6: Run the verification command​

Next, load the following environment variables into the shell.

export ETHERSCAN_API_KEY= # Your Etherscan API key
export ETHERSCAN_URL= # The Etherscan URL for the chain
export CONSTRUCTOR_ARG= # The constructor argument copied from Step 3
export CONTRACT_TO_VERIFY= # The contract address to verify

The CONTRACT_TO_VERIFY, in this example, is 0x0Ef0647B7324238bFA6084b54aD2d4Fd58d8E4ef.

If the function name from Step 1 is createMerkleLL, run the following command:

FOUNDRY_PROFILE=optimized \
forge verify-contract --etherscan-api-key $ETHERSCAN_API_KEY --verifier-url $ETHERSCAN_URL \
--constructor-args $CONSTRUCTOR_ARG $CONTRACT_TO_VERIFY \
src/SablierMerkleLL.sol:SablierMerkleLL --watch

If the function name is createMerkleLT, run the following command:

FOUNDRY_PROFILE=optimized \
forge verify-contract --etherscan-api-key $ETHERSCAN_API_KEY --verifier-url $ETHERSCAN_URL \
--constructor-args $CONSTRUCTOR_ARG $CONTRACT_TO_VERIFY \
src/SablierMerkleLT.sol:SablierMerkleLT --watch

If the function name is createMerkleInstant, run the following command:

FOUNDRY_PROFILE=optimized \
forge verify-contract --etherscan-api-key $ETHERSCAN_API_KEY --verifier-url $ETHERSCAN_URL \
--constructor-args $CONSTRUCTOR_ARG $CONTRACT_TO_VERIFY \
src/SablierMerkleInstant.sol:SablierMerkleInstant --watch

The campaign contract should now be verified on Etherscan. Thank you for reading! 💚