Skip to main content

In this tutorial we are going to add the MEV Blocker RPC into your browsers Web3 provider (Metamask, Rabby, etc.) and switch to it.

Connecting to MEV Blocker is as as simple as setting the right URL to connect to the RPC.

Different endpoints with different protections are available:

Frontrunning Backrunning Revert
/fast (default) ✅ Protected 💰 Refund ❌ Not Protected
/noreverts ✅ Protected 💰 Refund ✅ Protected
/fullprivacy ✅ Max protection ⦰ No refund ✅ Protected

Additionally, there are a few request parameters you can set to fine-tune the behavior of the RPC:

  • refundRecipient: Which address should receive searcher rebates (defaults to target tx.origin)
  • softcancel: Whether 0 value transactions to self should be broadcasted or interpreted as cancellation of other pending transactions at that nonce. Not available in fast endpoint.
  • referrer: Allows for order-flow attribution

Depending on your choice you may end up with a URL like:

https://rpc.mevblocker.io?refundRecipient=0x76bA9825A5F707F133124E4608F1F2Dd1EF4006a&softcancel=1&referrer=learn.cow.fi

Next: Sending Transactions

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
import type { Web3Provider } from '@ethersproject/providers';
 
export async function run(provider: Web3Provider): Promise<unknown> {
	const networkConfig = {
		chainId: '0x1', // Mainnet
		chainName: 'MEV Blocker',
		nativeCurrency: {
			name: 'ETH',
			symbol: 'ETH',
			decimals: 18
		},
		rpcUrls: [
			/* IMPLEMENT */
		],
		blockExplorerUrls: ['https://etherscan.io']
	};
 
	return await provider.send('wallet_addEthereumChain', [networkConfig]);
}
initialising