> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cow.bleu.builders/llms.txt
> Use this file to discover all available pages before exploring further.

# Contract Verification

> Guide for verifying CoW Protocol smart contracts on block explorers and Tenderly

# 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:

```bash theme={null}
# 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:

```bash theme={null}
yarn verify:etherscan --network mainnet --contract GPv2VaultRelayer \
  --constructor-args "0xBA12222222228d8Ba445958a75a0704d566BF2C8"
```

<Note>
  The Balancer Vault address `0xBA12222222228d8Ba445958a75a0704d566BF2C8` is consistent across all networks.
</Note>

## Tenderly Verification

Tenderly provides advanced debugging and monitoring capabilities.

### Setup

```bash theme={null}
# Authenticate with Tenderly
tenderly login
```

### Verify Contracts

```bash theme={null}
# 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:

```yaml theme={null}
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