mud verify

mud verify

This command uploads the source code for the deployed contracts to a public repository, such as a block explorer. The repository then compiles the source code and verifies that the compiled version is identical to what is deployed onchain.

The best time to perform verification is immediately after deployment. Verification only works with the original source code, compiler options, and compiled artifacts. Otherwise, the generated bytecode is different and therefore verification fails.


Currently, on Etherscan and Blockscout mud verify verifies the Systems that are part of your application, but not the MUD contracts themselves. On Sourcify mud verify verifies all the contracts.

Using the command

  1. If using Etherscan or Blockscout, specify the API key:

    export ETHERSCAN_API_KEY=<value goes here>

    With Blockscout you don't have to specify the API key. However, there is a limited number of requests allowed for accounts without an API key per second, so you get much more reliable service if you do.

  2. Run the command.

    pnpm mud verify --worldAddress <address here> --rpc <RPC to the blockchain> [--verifier <verifier>]

    These are the command line options you can specify on mud verify:

    OptionMeaningTypeDefault value
    --worldAddressVerify the contracts of the World at the given addressstringnone, error if unspecified
    --configPathPath to the config filestringmud.config.ts
    --verifierThe verifier to use (sourcify, or blockscout)stringblockscout
    --verifierUrlURL to use to access the verifier's APIstringdepends on the verifier used
    --profileThe foundry profile to usestringlocal
    --rpcURL to the blockchainstring
    --srcDirSource directorystringFoundry src directory
    --versionShow version numberbooleanfalse

    Note that it takes block explorers some time to process new contracts. You should wait 5-10 minutes past deployment before you verify the contract on Etherscan and/or Blockscout.


  • To verify the world at that address on Holesky on sourcify (opens in a new tab):

    pnpm mud verify --rpc $HOLESKY_RPC --worldAddress $WORLD_ADDRESS
  • To verify a contract on Holesky for users of Blockscout (opens in a new tab):

    export ETHERSCAN_API_KEY= ** blockscout API key goes here **
    pnpm mud verify --rpc $HOLESKY_RPC --worldAddress $WORLD_ADDRESS --verifier blockscout --verifier-url