Contract Verification
This guide explains how to verify CoW Protocol smart contracts on various block explorers, including Etherscan-based platforms and Tenderly.
Etherscan-Based Verification
Supported Explorers
| Network | Explorer |
|---|
| Ethereum | Etherscan |
| Gnosis Chain | Gnosisscan |
| Arbitrum | Arbiscan |
| Optimism | Optimistic Etherscan |
| Polygon | Polygonscan |
| BSC | BscScan |
| Base | Basescan |
| Avalanche | Snowtrace |
Batch Verification
Verify all deployed contracts at once:
# Set API key for the target network
export ETHERSCAN_API_KEY=your_api_key
# Run verification
yarn verify:etherscan --network $NETWORK
Individual Contract Verification
Certain contracts require constructor arguments for manual verification. The VaultRelayer requires the Balancer Vault address:
yarn verify:etherscan --network mainnet --contract GPv2VaultRelayer \
--constructor-args "0xBA12222222228d8Ba445958a75a0704d566BF2C8"
The Balancer Vault address 0xBA12222222228d8Ba445958a75a0704d566BF2C8 is consistent across all networks.
Tenderly Verification
Tenderly provides advanced debugging and monitoring capabilities.
Setup
# Authenticate with Tenderly
tenderly login
Verify Contracts
# Single contract
tenderly verify --name GPv2Settlement --address 0x9008D19f58AAbD9eD0D60971565AA8510560ab41
# Batch verification
tenderly verify --name GPv2Settlement --name GPv2VaultRelayer --name GPv2AllowListAuthentication
CI/CD Integration
Example GitHub Actions workflow:
name: Verify Contracts
on:
workflow_dispatch:
inputs:
network:
description: "Target network"
required: true
jobs:
verify:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- uses: actions/setup-node@v3
with:
node-version: "16"
- run: yarn install
- run: yarn build
- run: yarn verify:etherscan --network ${{ github.event.inputs.network }}
env:
ETHERSCAN_API_KEY: ${{ secrets.ETHERSCAN_API_KEY }}
Troubleshooting
| Issue | Solution |
|---|
| Already verified | Contract may already be verified on the explorer |
| Missing constructor arguments | Provide correct constructor args with --constructor-args |
| Invalid API key | Check API key validity and network match |
| Unsupported network | Verify that the explorer supports the target network |
Best Practices
- Verify contracts immediately after deployment
- Maintain deployment artifacts in version control
- Document constructor arguments thoroughly
- Test verification scripts before mainnet use
- Verify across multiple explorers for redundancy
