pyth-crosschain/target_chains/ethereum/contracts/VERIFY.md

Contract verification

The various EVM explorer sites (etherscan, bscscan, etc.) support contract verification. This essentially entails uploading the source code to the site, and they verify that the uploaded source code compiles to the same bytecode that's actually deployed. This enables the explorer to properly parse the transaction payloads according to the contract ABI.

This document outlines the process of verification. In general, you will need an API key for the relevant explorer (this can be obtained by creating an account), and also know which address the contract code lives. The API key is expected to be set in the ETHERSCAN_KEY environment variable for all APIs (not just etherscan, bit of a misnomer).

Our contracts are structured as a separate proxy and an implementation. Both of these components need to be verified, and truffle handles it.

Verifying the contract

Our contract is called PythUpgradable. To verify it on e.g. avalanche, at contract address 0x0e082F06FF657D94310cB8cE8B0D9a04541d8052, run

ETHERSCAN_KEY=... npm run verify --module=PythUpgradable --contract_address=0x0e082F06FF657D94310cB8cE8B0D9a04541d8052 --network=avalanche

(Note: the network name comes from the truffle-config.json). (Note: In this case, the ETHERSCAN_KEY is your snowtrace API key).

You might need to add the the explorer api keys in the truffle config api_keys. Please look at truffle-plugin-verify/utils.js to find the key names.

Note

The npm run verify script uses the truffle-plugin-verify plugin under the hood. The version of truffle-plugin-verify pinned in the repo (^0.5.11 at the time of writing) doesn't support the avalanche RPC. In later versions of the plugin, support was added, but other stuff has changed as well in the transitive dependencies, so it fails to parse the HDWallet arguments in our truffle-config.json. As a quick workaround, we backport the patch to 0.5.11 by applying the truffle-verify-constants.patch file, which the npm run verify script does transparently. Once the toolchain has been upgraded and the errors fixed, this patch can be removed.

Verifying with hardhat

Some chains might require users to verify with hardhat. Here are the additional steps :

• Add the chain to networks in hardhat.config.ts (equivalent of truffle-config.js)
• Add the explorer parameters to etherscan in hardhat.config.ts
• Run :

MNEMONIC=... npx hardhat verify 0x354bF866A4B006C9AF9d9e06d9364217A8616E12 --network shimmer_testnet

This process is somehow flaky. After running it, check the explorer as sometimes it will work even when it says it failed.