Understanding RPC endpoints for Ethereum

Every move you make on a decentralized exchange: from scoping out token prices to sealing the deal on a trade relies on one critical piece of infrastructure: RPC endpoints. These endpoints are the unsung heroes that connect DEXs to the blockchain, translating your intent into on-chain action. When RPC performance falters, so does the entire trading experience. For traders, this can mean missed opportunities, failed transactions, and unnecessary friction. For seamless, reliable, and MEV-resistant trading, high-quality RPC endpoints aren't just helpful, they're essential.

In this post we’ll be exploring how RPC endpoints impact DEX trading, the benefits of endpoints, and how you can use them to enhance security.

The basics: Remote Procedure Protocol endpoints

In simple terms, a Remote Procedure Call (RPC) is the bridge between your wallet and the blockchain. It's a communication protocol that lets one program (like your wallet interface) request data or actions from another program (like a blockchain node) - even if it's sitting on a completely different machine.

When you interact with a DEX, send a trade, or check your wallet balance, it's not magic - it's your wallet using an RPC endpoint to talk to the network. Think of the RPC as the translator and dispatcher. It routes your requests - whether it's querying token balances, fetching gas prices, or submitting a transaction - straight to the blockchain and back again, ideally in milliseconds.

For traders, this infrastructure matters more than you think. A reliable RPC endpoint means faster confirmations, accurate balance checks, and lower chances of failed transactions. A slow or overloaded RPC? That can mean missed opportunities, stale data, or frustrating reverts.

Most wallets and dApps connect to public RPCs by default - which are often crowded. But using custom or private RPCs (like MEV Blocker) can improve your trading experience by reducing latency, increasing throughput, and ensuring you're always working with up-to-date on-chain information.

Bottom line: if you're serious about trading on-chain, you should know how your wallet connects to the blockchain - and why the RPC behind it might be the quiet MVP of your whole setup.

RPC endpoints streamline and secure crypto transactions

At its core, an RPC endpoint is what ensures your wallet can communicate with the blockchain. But beyond that, it plays a direct role in how fast, reliable, and cost-effective your transactions are.

Let's break it down:

Reliability: In high-traffic situations - like NFT mints, token launches, or market surges - public RPCs can become congested. This increases the risk of failed or delayed transactions. A robust RPC endpoint keeps your transactions moving, making sure they reach the mempool and are broadcast to the network without unnecessary friction.

Speed: Execution speed can directly impact trading outcomes. Whether you're arbitraging, swapping, or cancelling an order, every second counts. A fast RPC connection minimizes latency and ensures that your orders are submitted and confirmed quickly - helping you secure better pricing and reduce slippage in volatile markets.

Lower Gas Fees: Accurate gas estimation is key to efficient trading. Good RPC endpoints provide up-to-date block data and fee suggestions, helping you avoid overpaying - or worse, underpaying and having a transaction fail. By optimizing how transactions are priced and prioritized, they help you minimize costs without compromising execution.

In short: the right RPC endpoint doesn't just connect you to the chain - it actively improves your ability to trade smarter, faster, and cheaper..

Public vs. private RPC endpoints

Not all RPC endpoints are created equal - especially when it comes to visibility. And in crypto, visibility = vulnerability.

When you send a transaction through a public RPC endpoint (like Infura, Alchemy, or QuickNode), your transaction enters the public mempool. That's essentially a waiting room where anyone - including MEV bots - can see your order before it's confirmed. This exposure opens the door to MEV attacks: frontrunning, sandwich attacks, and backruns that can extract value from your trades without your consent.

In contrast, private RPC endpoints are designed to shield your transactions from public view. Tools like MEV Blocker route your transaction through private relays - keeping it out of the public mempool and out of reach of predatory bots. This significantly reduces the chance of being targeted by MEV strategies that eat into your profits.

The difference comes down to who sees your transaction before it hits the chain. With private endpoints, visibility is limited to trusted relays. With public endpoints, it's a free-for-all.

There's another layer worth noting: tracking. Some public RPC providers have been known to log transaction metadata, wallet behavior, and trading patterns. While it may not be malicious, it's another form of exposure that privacy-conscious traders should care about.

So the choice is strategic. Public RPCs offer accessibility. Private RPCs offer protection. If you're actively trading, experimenting with new protocols, or just want to avoid unnecessary MEV slippage, switching to a private endpoint might be one of the lowest-lift, highest-impact moves you can make.

The below chart helps explain the differences between public and private RPC endpoints more clearly.

How private RPC endpoints protect against MEV

Privacy is the foundation of MEV protection - but it's not the whole picture. Once your transaction is hidden from the public mempool, what happens next depends on how that private system is designed. The best RPC endpoints don't stop at concealment. They actively optimize for fair execution, value sharing, and transaction reliability.

Let's break it down:

Trusted Validators

In a private RPC environment, your transaction doesn't just need privacy - it needs a trustworthy path to the chain. That's where curated validator sets come in. These are validators that commit to ethical execution - no frontrunning, no sandwiching, no games. It ensures that even after your transaction is out of public view, it's not being manipulated by bad actors at the validator level.

Rebates via Backrunning

Here's where privacy meets strategy. Some RPC endpoints - like MEV Blocker and advanced bundlers - selectively allow backrunning (executing a transaction immediately after yours) in controlled environments. We call them rebates. When value is extracted, a portion of that MEV is given back to you. That turns what was once a loss into a financial incentive, helping offset gas fees or increase net gains.

Preventing Reverts

Failed transactions waste gas and erode trust. Smart RPC endpoints validate transactions before inclusion, or cancel the broadcast altogether if the transaction becomes invalid (due to price changes, slippage, etc.). The result? Fewer reverts, fewer surprises, and more confidence at the point of click.

Together, these tactics turn a private RPC from a black box into a value-aligned pipeline - one that protects, rewards, and optimizes every transaction you send.

Protective endpoints in MEV Blocker

MEV Blocker is more than just a private RPC - it's a purpose-built shield against the most common and costly MEV (Maximal Extractable Value) attacks, like frontrunning and sandwiching. By routing transactions away from the public mempool and through a private network of trusted searchers, or solvers as we call them, it helps ensure your trades land where they should - not as profit opportunities for bots.

But not all trades are the same. That's why MEV Blocker offers multiple RPC configurations, giving users the flexibility to choose what they care about most: speed, privacy, reliability, or rewards.

Here's how each endpoint works:

• Fast Endpoint: Best for speed and simplicity. This endpoint offers basic MEV protection and potential rebates, routing your transaction through trusted searchers. It's built for fast inclusion but doesn't guard against transaction reverts.

• Full Privacy Endpoint: Designed for maximum confidentiality. Your transaction is sent directly to builders, skipping searchers entirely. This offers the strongest privacy and MEV protection, and crucially, prevents reverts. The tradeoff? No rebate opportunities.

• No-Revert Endpoint: Optimized for reliability. This option blocks invalid transactions from being broadcast at all, eliminating reverts and wasted gas. It includes both MEV protection and rebate potential, striking a strong balance between safety and efficiency.

• Max Backruns Endpoint: Ideal for value maximizers. This endpoint widely shares your transaction with trusted searchers to enable maximum rebate opportunities. It protects against harmful MEV but doesn't prevent reverts, so timing matters.

With MEV Blocker, users can match their transaction goals to a routing strategy - and finally take control of how their orders are handled on-chain.

How CoW integrates RPC endpoints with a meta-DEX

At CoW Swap, protecting users from MEV isn't an afterthought - it's built into the infrastructure. By integrating MEV Blocker's RPC endpoints directly into its trading flow, CoW Swap ensures that every user transaction benefits from privacy, security, and optimized execution.

Here's how it works under the hood:

When a user initiates a trade on CoW Swap, the transaction is routed through a private RPC endpoint. This prevents it from entering the public mempool - where it could be exposed to frontrunning or sandwich attacks - and instead channels it through MEV Blocker's protected environment.

But the benefits go beyond shielding. CoW Swap uses its RPC layer to power batch auctions, where multiple orders are settled together in tightly timed blocks. This approach enables:

• Improved price discovery

• Reduced slippage

• Efficient gas usage

Instead of competing with bots, your order joins a group - and solvers (specialized agents) compete to fill those orders at the best possible rate.

Traders can also submit "intent to trade" messages - statements of what they want to swap, under what conditions. These intents are transmitted via the RPC layer to the CoW Protocol, where solvers then route liquidity from the most efficient source - whether that's a matching user order or a DEX like Uniswap, Balancer, Curve or even private liquidity pools most users wouldn’t be able to access.

The result? Users trade on their terms, with better protection, better pricing, and zero need to micromanage execution risk.

This isn't just a DEX. It's a meta-DEX - one that uses smart routing and a privacy-first RPC network to reshape how trades are made in DeFi.

Endpoint architecture: full, light, and archive nodes

Behind every RPC endpoint is a network of Ethereum nodes - each serving a different purpose depending on how much data they store and how fast they can serve it. For traders, understanding this architecture helps clarify why certain endpoints feel faster, offer more context, or provide deeper visibility into past activity.

Here's the breakdown:

Full Nodes

These are the workhorses of the RPC world. Full nodes maintain all current blockchain data: recent transactions, token balances, smart contract states, and real-time event logs. They don't store the full history of Ethereum, but they have everything you need to trade, manage positions, and interact with live protocols.

CoW Swap's MEV Blocker operates on full nodes - ensuring up-to-date data and fast response times without compromising on MEV protection.

Best for: Active trading, portfolio tracking, and real-time DEX interactions.

Light Nodes

Light nodes play a crucial role in blockchain ecosystems by offering a leaner, more resource-efficient alternative to full or archive nodes. Instead of storing the entire blockchain, light nodes retain only the most essential data, such as block headers. This allows them to verify the validity of transactions without needing the full transaction history or state data.

They're key for:

• Resource-Constrained Environments: Ideal for mobile wallets, browser extensions, or lightweight applications where full node storage isn’t feasible.
• Quick Access to Basic Blockchain Data: Useful for fast tasks like checking balances, verifying transaction inclusion, or syncing recent blocks without downloading the full chain.
• Interfacing with Full Nodes: Serve as efficient front-ends that delegate heavy computation and validation to trusted full nodes, enabling low-bandwidth blockchain access.

Best for: Traders looking for quick, esay access to simple onchain data. .

Archive Nodes

Archive nodes store compressed blockchain data and rely on full nodes to fetch deeper details. But where they shine is in access to historical trading data - past balances, old transactions, and smart contract logs.

They're key for:

• Historical market analysis
• Advanced trading strategies
• Deep audit trails and analytics

Best for: Traders doing historical performance reviews, tax reports, or backtesting.

Different nodes serve different needs - and the right RPC setup will prioritize node types based on the use case: speed, history, privacy, or resilience.

Setting up RPC endpoints with MEV Blocker

Getting started with MEV Blocker is a low-friction, high-impact upgrade for any trader or dApp builder looking to protect users from MEV exploitation. Whether you're an active DeFi user or a developer building for others, the setup process is straightforward - and worth doing right.

1. Select the Right Endpoint for Your Needs

Start by identifying what matters most in your trading or application flow:

• Speed? Use the Fast endpoint.

• Privacy and revert protection? Go with Full Privacy.

• Reliability? Choose No-Revert.

• Rebates and value sharing? Try Max Backruns.

Each endpoint is tuned for a specific tradeoff between protection, performance, and incentives. Choosing the right one ensures you're aligning the tech with your strategy - whether that's sniping a price, safeguarding a large order, or routing user transactions at scale.

2. Integrate the MEV Blocker Endpoint

Once you've chosen your endpoint, integration is as simple as replacing the default RPC URL in your wallet, script, or frontend with the MEV Blocker URL.

Most wallets (e.g., MetaMask, Rabby) allow easy RPC switching. For developers, simply update your Web3 provider or backend config. This swap immediately routes your transactions away from the public mempool and through a privacy-preserving pipeline.

3. Test for Connectivity and Stability

Run a few test transactions or simulated calls through the new endpoint. Confirm that:

• Transactions are sent and confirmed successfully.

• Gas estimates and responses are accurate.

• No unexpected errors surface in your stack.

• This ensures confidence before putting real capital at risk.

4. Monitor Performance and Stay Updated

Set up basic monitoring: track transaction success rates, watch for latency issues, and check logs for abnormalities. CoW.fi may update endpoint availability or add new features - staying informed keeps your connection secure and high-performing.

With the right endpoint, a few config changes, and some initial testing, MEV protection becomes not just possible - but effortless and native to your workflow.

Tips for developers: implementing RPC endpoints

For developers building dApps, trading tools, or wallet integrations, switching to a private RPC endpoint is one of the simplest ways to protect users from MEV and improve transaction reliability. Here's how to implement it with minimal friction - and maximum impact.

1. Evaluate Your RPC Provider Carefully

Not all RPCs are created equal. Choose providers with:

• High uptime and low latency

• Proven MEV protection features

• Transparent policies around data use

• A solid reputation in the Ethereum dev community

MEV Blocker, built by CoW Protocol, is a strong choice - designed to align execution with user interests, not extract value from them.

2. Replace Public RPCs with Private Endpoints

Wherever your app defines its Ethereum provider, swap in a private RPC URL. This can be done in:

• MetaMask settings

• Custom wallet configs

• Backend infrastructure (e.g., INFURA_URL → MEV_BLOCKER_URL)

Use endpoint URLs that match your app's priorities: speed, privacy, no-reverts, or rebate-maximization.

3. Integrate with Popular Frameworks Easily

Whether you're using React, Node.js, Web3.js, or Ethers.js, integration is straightforward. For example:

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://rpc.mevblocker.org');

Use vetted documentation and keep implementation lightweight.

4. Follow Transaction Privacy Best Practices

Below are the three key areas to think about thinking about preserving privacy.

• Consider transaction batching to reduce exposure.

• Use encrypted connections (https://, not http://).

• Route through private mempools to avoid public broadcast.

5. Monitor and Log Endpoint Access

Set up logs to track:

• RPC call volume

• Error rates

• Latency spikes

• Unexpected request patterns

This helps detect outages, catch anomalies, and ensure users are always protected.

Next steps

Interested in learning more about MEV Blocker? Try this guide.

Want to learn more about how meta-DEXs like CoW can integrate private endpoints? Try these related resources:

• A guide to MEV on Ethereum - CoW DAO

• What is a Meta DEX - and why should you use it for your trades? - CoW DAO

• How to choose a DEX aggregator - CoW DAO