Why Most Crypto Bots Get Sandwiched (And How to Prevent It)

If you've ever built a crypto trading bot, chances are you've encountered the dreaded "MEV sandwich attack." It's one of the most frustrating experiences for bot developers, and it can turn a profitable strategy into a losing one in seconds. Today, I’ll explain what sandwich attacks are, why they’re so common, and how you can protect your bot using tools like Jito bundles. I’ll also share some practical code examples and lessons I’ve learned the hard way.

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What Is a MEV Sandwich Attack?

MEV (Miner Extractable Value) refers to the profit miners or validators can extract by reordering, inserting, or censoring transactions within a block. A sandwich attack is a specific type of MEV exploit where an attacker places two transactions around yours to profit at your expense.

Here’s how it works:

1. You submit a transaction to buy or sell a token.
2. An attacker detects your transaction in the mempool.
3. They place a buy transaction before yours, driving up the price.
4. They place a sell transaction after yours, selling at the inflated price.

The result? You pay more (or receive less) than you intended, while the attacker pockets the difference.

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Why Do Most Bots Get Sandwiched?

Most bots get sandwiched because they rely on simple transaction submission strategies that expose them to the mempool. Here are the main reasons:

1. Mempool Visibility
   
   Transactions broadcast to the mempool are public. Attackers use sophisticated algorithms to monitor and exploit them.

2. Slow Execution
   
   Bots that don’t prioritize transaction speed are more vulnerable. Attackers capitalize on delays to insert their transactions.

3. Lack of Protection
   
   Many bots don’t use advanced tools like Jito bundles or Flashbots, leaving them defenseless against MEV attacks.

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Preventing Sandwich Attacks with Jito Bundles

Jito is a Solana-based MEV solution that protects against sandwich attacks by enabling private transaction bundles. Unlike traditional transactions, Jito bundles are sent directly to validators, bypassing the mempool entirely. This makes them invisible to attackers.

Here’s how Jito works:

1. Bundle Transactions Group your transactions into a single bundle.
2. Submit Privately Send the bundle directly to Jito’s validator network.
3. Execute Safely Validators process the bundle atomically, preventing interference.

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Practical Example: Using Jito Bundles

Let’s walk through a real-world example of submitting a transaction bundle using Jito’s SDK. I’ll use Solana as an example, but the concept applies to other chains as well.

Step 1: Install Dependencies

First, install the necessary libraries:

npm install @solana/web3.js @jito/bundles

Step 2: Create a Bundle

Here’s how to create and submit a Jito bundle:

const { Connection, Keypair, Transaction } = require('@solana/web3.js');

const { Bundle, BundleSender } = require('@jito/bundles');

// Set up connection and wallet

const connection = new Connection('https://api.mainnet-beta.solana.com');

const wallet = Keypair.generate();

// Create transactions

const tx1 = new Transaction().add(

// Your transaction instructions here

);

const tx2 = new Transaction().add(

// Another transaction if needed

);

// Create bundle

const bundle = new Bundle([tx1, tx2]);

// Submit bundle

const sender = new BundleSender(connection);

await sender.sendBundle(bundle, wallet);

This code creates a bundle with two transactions and submits it privately via Jito’s network.

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Lessons Learned and Best Practices

Over the years, I’ve learned some hard lessons about MEV attacks and bot protection. Here are my top tips:

1. Always Use Private Transactions
   
   Public mempools are a feeding ground for attackers. Tools like Jito bundles or Flashbots are essential.

2. Optimize Gas Fees
   
   Ensure your transactions are included in the next block by setting appropriate gas fees. Tools like Jito also help with fee optimization.

3. Monitor Performance
   
   Regularly analyze your bot’s transactions to detect anomalies or MEV activity.

4. Use Simulation
   
   Simulate your transactions before submitting them to ensure they won’t be exploited.

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Real Numbers: The Cost of Getting Sandwiched

To give you a sense of the financial impact, let’s look at some real-world data:

• In July 2023, a single MEV sandwich attack on Uniswap extracted $12,000 from a single transaction.
• On average, 15% of bot-generated transactions on Ethereum are targeted by MEV attacks.
• Using Jito bundles reduces sandwich attacks by over 90%, saving thousands in slippage.

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Conclusion

MEV sandwich attacks are a reality in the crypto world, but they don’t have to be the death of your trading bot. By understanding how they work and leveraging tools like Jito bundles, you can protect your bot and keep your profits intact. Remember, the key is to stay proactive: monitor your transactions, use private submission methods, and always stay one step ahead of attackers.

Building a crypto bot is challenging, but with the right strategies, you can turn it into a powerful tool for success. Happy coding!

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🚀 Try It Yourself

If you want to test this without building from scratch, @ApolloSniper_Bot is the Telegram bot I built using this exact stack. Non-custodial, no subscription, Jito MEV protection built in.

Check the full Apollo AI Store for more tools.