Verify a smart contract on Monad using Foundry

Once your contract is deployed to a live network, the next step is to verify its source code on the block explorer.

Verifying a contract means uploading its source code, along with the settings used to compile the code, to a repository (typically maintained by a block explorer). This allows anyone to compile it and compare the generated bytecode with what is deployed on chain. Doing this is extremely important in an open platform like Monad.

In this guide we'll explain how to do this using Foundry.

Foundry Monad template (Recommended)

If you are using foundry-monad template, you can use the commands below based on your preferred block explorer:

MonadExplorer

forge verify-contract \
    <contract_address> \
    <contract_name> \
    --chain 10143 \
    --verifier sourcify \
    --verifier-url https://sourcify-api-monad.blockvision.org

Example:

forge verify-contract \
    0x8fEc29BdEd7A618ab6E3CD945456A79163995769 \
    Counter \
    --chain 10143 \
    --verifier sourcify \
    --verifier-url https://sourcify-api-monad.blockvision.org

On successful verification of smart contract, you should get a similar output in your terminal:

Start verifying contract `0x8fEc29BdEd7A618ab6E3CD945456A79163995769` deployed on monad-testnet
Attempting to verify on Sourcify. Pass the --etherscan-api-key <API_KEY> to verify on Etherscan, or use the --verifier flag to verify on another provider.

Submitting verification for [Counter] "0x8fEc29BdEd7A618ab6E3CD945456A79163995769".
Contract successfully verified

Now check the contract on MonadExplorer.

Monadscan

forge verify-contract \
    <contract_address> \
    <contract_name> \
    --chain 10143 \
    --verifier etherscan \
    --etherscan-api-key YourApiKeyToken \
    --watch

Example:

forge verify-contract \
    0x8fEc29BdEd7A618ab6E3CD945456A79163995769 \
    Counter \
    --chain 10143 \
    --verifier etherscan \
    --etherscan-api-key YourApiKeyToken \
    --watch

On successful verification of smart contract, you should get a similar output in your terminal:

Start verifying contract `0x8fEc29BdEd7A618ab6E3CD945456A79163995769` deployed on monad-testnet

Submitting verification for [src/Counter.sol:Counter] 0x8fEc29BdEd7A618ab6E3CD945456A79163995769.
Submitted contract for verification:
        Response: `OK`
        GUID: `fhxxx4wsub68jce24ejvhe68fqabgtpmpzheqpdqvencgph1za`
        URL: https://testnet.monadscan.com/address/0x8fec29bded7a618ab6e3cd945456a79163995769
Contract verification status:
Response: `NOTOK`
Details: `Pending in queue`
Warning: Verification is still pending...; waiting 15 seconds before trying again (7 tries remaining)
Contract verification status:
Response: `OK`
Details: `Pass - Verified`
Contract successfully verified

Now check the contract on Monadscan.

Socialscan

forge verify-contract \
    <contract_address> \
    <contract_name> \
    --chain 10143 \
    --watch \
    --etherscan-api-key <your_api_key> \
    --verifier-url https://api.socialscan.io/monad-testnet/v1/explorer/command_api/contract \
    --verifier etherscan

Example:

forge verify-contract \
    0x8fEc29BdEd7A618ab6E3CD945456A79163995769 \
    Counter \
    --chain 10143 \
    --watch \
    --etherscan-api-key test \
    --verifier-url https://api.socialscan.io/monad-testnet/v1/explorer/command_api/contract \
    --verifier etherscan

On successful verification of smart contract, you should get a similar output in your terminal:

Start verifying contract `0x8fEc29BdEd7A618ab6E3CD945456A79163995769` deployed on monad-testnet

Submitting verification for [src/Counter.sol:Counter] 0x8fEc29BdEd7A618ab6E3CD945456A79163995769.
Submitted contract for verification:
        Response: `Contract successfully verified`
        GUID: `33588004868f0677a3c23734da00fc42895a63542f61b1ed0dbfd2eb6893d7f4`
        URL: https://api.socialscan.io/monad-testnet/v1/explorer/command_api/address/0x8fec29bded7a618ab6e3cd945456a79163995769
Contract verification status:
Response: `OK`
Details: `Pass - Verified`
Contract successfully verified

Now check the contract on Socialscan.

Default Foundry Project

tip

If you use foundry-monad you can skip the configuration step

1. Update foundry.toml with Monad Configuration

foundry.toml

1234567891011
[profile.default]
src = "src"
out = "out"
libs = ["lib"]  
metadata = true
metadata_hash = "none"  # disable ipfs
use_literal_content = true # use source code

# Monad Configuration
eth-rpc-url="https://testnet-rpc.monad.xyz"
chain_id = 10143

2. Verify the contract using one of the following block explorers:

MonadExplorer

forge verify-contract \
    <contract_address> \
    <contract_name> \
    --chain 10143 \
    --verifier sourcify \
    --verifier-url https://sourcify-api-monad.blockvision.org

Example:

forge verify-contract \
    0x8fEc29BdEd7A618ab6E3CD945456A79163995769 \
    Counter \
    --chain 10143 \
    --verifier sourcify \
    --verifier-url https://sourcify-api-monad.blockvision.org

On successful verification of smart contract, you should get a similar output in your terminal:

Start verifying contract `0x8fEc29BdEd7A618ab6E3CD945456A79163995769` deployed on monad-testnet
Attempting to verify on Sourcify. Pass the --etherscan-api-key <API_KEY> to verify on Etherscan, or use the --verifier flag to verify on another provider.

Submitting verification for [Counter] "0x8fEc29BdEd7A618ab6E3CD945456A79163995769".
Contract successfully verified

Now check the contract on MonadExplorer.

Monadscan

forge verify-contract \
    <contract_address> \
    <contract_name> \
    --chain 10143 \
    --verifier etherscan \
    --etherscan-api-key YourApiKeyToken \
    --watch

Example:

forge verify-contract \
    0x8fEc29BdEd7A618ab6E3CD945456A79163995769 \
    Counter \
    --chain 10143 \
    --verifier etherscan \
    --etherscan-api-key YourApiKeyToken \
    --watch

On successful verification of smart contract, you should get a similar output in your terminal:

Start verifying contract `0x8fEc29BdEd7A618ab6E3CD945456A79163995769` deployed on monad-testnet

Submitting verification for [src/Counter.sol:Counter] 0x8fEc29BdEd7A618ab6E3CD945456A79163995769.
Submitted contract for verification:
        Response: `OK`
        GUID: `fhxxx4wsub68jce24ejvhe68fqabgtpmpzheqpdqvencgph1za`
        URL: https://testnet.monadexplorer.com/address/0x8fec29bded7a618ab6e3cd945456a79163995769
Contract verification status:
Response: `NOTOK`
Details: `Pending in queue`
Warning: Verification is still pending...; waiting 15 seconds before trying again (7 tries remaining)
Contract verification status:
Response: `OK`
Details: `Pass - Verified`
Contract successfully verified

Now check the contract on Monadscan.

Socialscan

forge verify-contract \
    <contract_address> \
    <contract_name> \
    --chain 10143 \
    --watch \
    --etherscan-api-key <your_api_key> \
    --verifier-url https://api.socialscan.io/monad-testnet/v1/explorer/command_api/contract \
    --verifier etherscan

Example:

forge verify-contract \
    0x8fEc29BdEd7A618ab6E3CD945456A79163995769 \
    Counter \
    --chain 10143 \
    --watch \
    --etherscan-api-key test \
    --verifier-url https://api.socialscan.io/monad-testnet/v1/explorer/command_api/contract \
    --verifier etherscan

On successful verification of smart contract, you should get a similar output in your terminal:

Start verifying contract `0x8fEc29BdEd7A618ab6E3CD945456A79163995769` deployed on monad-testnet

Submitting verification for [src/Counter.sol:Counter] 0x8fEc29BdEd7A618ab6E3CD945456A79163995769.
Submitted contract for verification:
        Response: `Contract successfully verified`
        GUID: `33588004868f0677a3c23734da00fc42895a63542f61b1ed0dbfd2eb6893d7f4`
        URL: https://testnet.monadexplorer.com/address/0x8fec29bded7a618ab6e3cd945456a79163995769
Contract verification status:
Response: `OK`
Details: `Pass - Verified`
Contract successfully verified

Now check the contract on Socialscan.