Connecting to the Blockchain with RPC Nodes

June 27, 2023 - 4 min read

While running a custom RPC node might have its advantages, the average developer will find that there are services out there ready to do the heavy lifting.

What is an RPC Node?

Remote Procedure Call nodes are servers that process requests and return responses from one node to a larger network. They’re used by applications to remotely interact with networks like blockchains. A procedure call is also known as a function call or a subroutine call.

In order for smart contracts to be automated so as to execute transactions quickly and without centralized control, they need to have pristine data. That is, the old saying “garbage in, garbage out” is especially poignant for Web3, AI, or any other automated service.

RPC nodes act as gateways or portals into a blockchain’s ecosystem, but just because they can communicate with the blockchain does not mean that their data will be accepted. Incoming ledger data is validated by blockchain nodes via decentralized consensus, and so the RPC node can only send requests to a blockchain network – it has no authority to impose any reality upon the network without the participation of the given blockchain.

RPC nodes are the mouthpieces for Web3 dApps. For example, if you are using a decentralized exchange (DEX), and request to swap one token for another, the DEX would need to first check if your wallet is valid and signed off on the transaction before communicating this information with the blockchain via RPC nodes. Our example DEX must communicate two things to its desired blockchain:

Your wallet is valid and has an adequate balance to swap the desired token.
Route the transaction to a blockchain via RPC node.

Following this, the blockchain’s validator nodes will reach a consensus regarding the validation and then on-chain execution in the form of a new block added to the chain. An RPC node doesn’t validate transactions by itself, since it needs to get the consensus of the other participants in the larger blockchain ecosystem which keeps everyone honest. For more on this, see this write-up about the Byzantine Generals Problem.

Setting up RPC Node Endpoints

All dApps wanting to communicate with blockchains must do so using an RPC endpoint. That is, communications from RPC nodes will need to be directed to specific node endpoints like Devnet, Testnet, or Mainnet.

Setting up an RPC node requires one to be familiar with using a command line interface and have relatively capable hardware. Generally speaking, it’s most convenient to go with a ready-made RPC service. To run your own Ethereum RPC node, you’ll need to install Geth, which is the Go implementation of an Ethereum node.

This is arguably the most popular option for running a node. Installation instructions depend on your operating system, but for Mac, Windows, and Linux, you can install it using the built-in package managers. Once you’ve installed Geth, you can start the Ethereum node. With just a few lines of command to sync with the Ethereum blockchain, you can then get your RPC node up and running.

Remember to secure your RPC node, especially if you’re leaving it open to allowing connections from any IP address. Any failure to properly secure connectivity parameters could allow for attackers to gain control over your RPC node and wreak havoc on your dApp, its users, and their assets.

Once your RPC node is set up, you can start making RPC calls to the blockchain. Libraries are available for a variety of programming languages so that you can interact with an Ethereum node in the way that suits you best. For example, if you prefer Web3.js for JavaScript or Web3.py for Python, you’ll be good to go.

Making the Difficult Easy: RPC Node Services

Running an RPC node often requires powerful hardware and plenty of network bandwidth since it needs to process transactions and store the blockchain ledger’s history. Consequently, more and more users are turning to Web3 service providers like Infura or Alchemy, which connect dApps to shared RPC nodes instead of building, maintaining, and operating their own RPC nodes.

Infura offers a bit more variety, while Alchemy focuses more on the Ethereum ecosystem and its Layer 2 scaling solutions. However, deciding which one is the best should probably be based on performance.

While there are variabilities when it comes to the networks themselves, comparing RPC node services running on Ethereum should provide reasonably actionable results. Quicknode is probably the fastest and most reliable, with Alchemy and Infura being close behind with extremely comparable experiences regarding response times and reliability.

Improving the availability and security of communications in Web3, along with a major emphasis on UX, is crucial to driving mass adoption of this tech. As the tools for developers become more sophisticated, the talent building in the space will continue to expand in their numbers and capabilities. This forward momentum reaching escape velocity will only be a matter of time.