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Register a contract's methods names

MetaMask uses the Parity on-chain registry of function signatures to display method names on the confirm screen. For many common method names, such as token methods, this allows MetaMask to successfully look up the method names by their method signature. However, sometimes you're using a method that isn't in that on-chain registry, and MetaMask simply displays Contract Interaction to the user.

To add your contract's function names to this registry so it shows in the MetaMask interface, follow these steps:

  1. Go to the Mainnet Parity signature registration contract on Etherscan.

  2. Connect MetaMask.

  3. Use Etherscan's write contract feature to input the string value (without quotes or spaces) to the register function. For example:

    getOwners()

    execTransaction(address,uint256,bytes,uint8,uint256,uint256,uint256,address,address,bytes)

  4. Select write.

  5. Approve the transaction in MetaMask (you only pay gas).

Verify​

ethers.utils.keccak256('getOwners()') => 0xa0e67e2bdc0a6d8a09ccd6c353c9df590807ad66ff5e6630c4f31a86dfa84821

Input the first 10 characters, 0xa0e67e2b, into this demo app that checks the on-chain registry (Mainnet or Rinkeby only).

Use Remix​

  1. Paste the contract code from bokky's blog post into Remix.
  2. Set the correct compiler version based on the contract.
  3. Use Remix's write functionality to add to the registry.
  4. You can look at the FUNCTIONHASHES section on Remix by loading the signature registry contract, and selecting details on the compile tab.

Use eth-method-registry​

You can also use the signature registry deployed on Rinkeby.

eth-method-registry is used to lookup methods in MetaMask.

note

MetaMask reads from the mainnet eth-method-registry endpoint, regardless of the user's network.

For more details, see this StackExchange answer.