What is an RPC Node? Function, How It Works, and Its Importance in Web3

In its implementation, a dApp (Decentralized Application) receives data from the blockchain to fulfill user requests, such as sending transactions, accessing block data, or evaluating the status of the blockchain.

How does a dApp connect to the blockchain? It utilizes a Remote Procedure Call (RPC) node that enables an application to interact with the blockchain.

This article will discuss all you need to know about RPC nodes. Read on to learn about RPC nodes and understand how they work!

Brief Summary:

1. An RPC (Remote Procedure Call) node is a blockchain node that allows dApps or wallets to interact with the blockchain.
2. Almost all activities on the blockchain (checking wallet balances, sending transactions, checking smart contract data, etc.) are made possible by RPC nodes.
3. RPC nodes are categorized into RPCs with public and private endpoints.

RPC Node Definition

What is RPC?

Before discussing what an RPC node is, we must first understand the meaning of RPC itself. RPC, or Remote Procedure Call, is a method in computer science that allows a program to request services or data from another program operating on a different network or machine.

The basic principle of RPC is quite simple. A developer does not need to worry about complicated network differences. They simply issue a command, and the RPC mechanism sends the command to a different network and brings back results.

Think of RPC like ordering food at a restaurant. Customers don’t go into the kitchen and cook their own food. They simply give their order to the waiter, who will deliver it to the kitchen. When the food is ready, the waiter will serve it to the customers’ tables.

In this analogy, customers are the applications that issue commands, waiters serve as the RPC mechanism, and the kitchen is the system or server where the command is processed.

What is an RPC Node?

An RPC node is a blockchain node that provides an interface for dApps to interact with the network. This node receives requests from dApps or wallets, broadcasts them to the blockchain, and then sends back the results.

In the context of blockchain, RPC nodes act as translators and messengers. Human requests are translated into commands that the network understands, and then the results are returned in a developer-friendly format.

Without RPC nodes, wallet or dApp users and developers cannot interact with blockchains such as Ethereum, Solana, and others. This is why RPC nodes are often referred to as the “API layer” for blockchains.

How RPC Nodes Work

After learning about RPC nodes, it's time to understand the technology behind RPC requests in blockchain.

JSON-RPC

The standard RPC specification used in blockchain is called JSON-RPC. This specification is widely used because it can quickly receive and process data requests.

If the RPC endpoint is a server, then JSON-RPC is a specific method for requesting services from the RPC endpoint. These methods are divided into three categories.

1. Gossip Method: Tracks the head of the chain and locates blocks.
2. State Method: Reports the current status of all blockchain data.
3. History Method: Provides the historical record of any block in a chain.

How an RPC Node Works (Step-by-Step)

We already understand what an RPC node is, but how does it work? Simply put, an RPC node acts as a middle layer between a dApp and the blockchain. Here is the process in detail:

1. Application Sends Requests: dApps, wallets, or services send a request to the RPC node.
2. RPC Node interprets Requests
3. For read requests: The node reads the local blockchain status.
4. For write requests: The node broadcasts the transaction to the blockchain network.
5. Blockchain Processes Requests:
6. For read requests: The node already owns the data because it’s synchronized with the blockchain.
7. For write requests: The transaction is validated, propagated, and registered to a block.
8. Results are Sent Back to the Application: The RPC node formats the results as a JSON-RPC response and sends it to the dApp.

This process occurs constantly whenever you perform an activity that requires direct interaction with the blockchain, such as checking the token balance in your wallet, minting NFTs, or interacting with DeFi protocols.

Also Read: Decentralized Finance (DeFi): Definition & How It Works

The Role of RPC Nodes in Blockchain

Many novice dApp users still don't understand the ins and outs of RPC nodes, even though this technology holds a central role in dApp operations. RPC nodes power almost all interactions on the blockchain. Here are several roles of RPC nodes in wallets, dApps, and other blockchain services.

Checking Wallet Balance

When you open a wallet application such as MetaMask or Phantom, the wallet sends an RPC request to access your token balance.

Sending Transactions

When a user approves a transaction, the wallet broadcasts the transaction via an RPC node. The RPC node then sends it to the blockchain network to be validated and added in a block.

Reading Smart Contract Data

dApps use RPC nodes to access information stored in smart contracts. For example, DeFi applications check tokens stored in liquidity pools, or NFT marketplaces use RPC nodes to verify token ownership.

NFTs and Gaming

NFT platforms rely on RPC nodes to verify token ownership, access metadata, and process newly minted NFTs. Blockchain games also use RPC nodes to update in-game states that utilize on-chain data.

DeFi Operations

Protocols such as Uniswap, Aave, or Compound constantly request on-chain data like token prices and lending pool reserves through RPC requests. Without relying on RPC, these platforms cannot function in real-time.

Analytics and Monitoring

Blockchain explorers, portfolio trackers, and on-chain analytics tools retrieve large amounts of data via an RPC node. RPC nodes aggregate transaction history, block details, and smart contract activities in a human-readable format.

Types of RPC Nodes

Types of RPC nodes can be categorized based on the nature of their endpoints.

Public RPC Endpoint

Public RPC endpoints are open nodes that are free and accessible to anyone. Developers can connect to the blockchain without disrupting their app’s infrastructure. Public RPC endpoints are used for:

1. dApp testing
2. Wallets requiring decentralized access
3. Block explorers with educational and experimental insights

Private RPC Endpoint

Private RPC endpoints are nodes with limited access to specific users. Therefore, they have higher throughput than public endpoints. They are used for:

1. dApps with moderate traffic that need stable performance
2. Wallets with hundreds of users
3. Block explorers that display real-time data

Dedicated Blockchain Nodes

In addition to RPC nodes with public and private endpoints, there are also dedicated blockchain nodes that only serve one application. They have lower latency, higher throughput, and much faster performance. Dedicated blockchain nodes are used for:

1. High-performance dApps that are sensitive to time changes, such as trading and DeFi protocols
2. Wallets with high transaction volumes
3. Block explorers that provide real-time analysis for multiple blockchains at once
4. Traders who need fast on-chain transactions

Examples of RPC Node Providers

GetBlock: Best for Low-Latency Apps

1. Supports over 100 blockchains.
2. Endpoints can be selected based on geolocation, including Frankfurt, New York, and Singapore, for low latency.
3. Node-layer protection for sensitive DeFi order flows.
4. Throughput of 20-1000 RPS (requests per second).
5. Median latency: 18.6 ms (Asia Pacific), 34.6 ms (United States), 107 ms (Europe).

Alchemy: RPC Platform with Developer-Friendly APIs

1. Supports over 80 blockchains.
2. Advanced APIs such as NFT API, token API, portfolio API, transfer API, and gasless transactions.
3. Transaction simulation and private transaction support.
4. Throughput reaches 300 RPS.
5. Median latency: 35.9 ms (Asia Pacific), 65.3 (United States), 104 ms (Europe).

QuickNode: Rich Add-On Options

1. Supports over 70 blockchains.
2. Extensive add-on options with customized tools.
3. Partner integrations for DeFi and analytics.
4. Throughput from 15-500 RPS and customizable limits.
5. Latency: global average of 25 ms.

Ankr: A Node Ecosystem with Token Incentives

1. Supports over 80 blockchains.
2. Decentralized architecture with a multi-operator model.
3. Supports staking with a native token to support node operators.
4. Throughput up to 1500 RPS.
5. Latency: 28.3 ms (Asia Pacific), 29.8 ms (United States), 114 ms (Europe).

Infura: Designed for the Ethereum Ecosystem

1. Supports over 20 blockchains, including Ethereum and major layer 2s such as Arbitrum, Optimism, Polygon, and Base.
2. Utilized Decentralized Infrastructure Network (DIN) with major providers.
3. Built-in integration with Ethereum tools (MetaMask, Hardhat, ethers.js, and others).
4. Throughput from 5-1800 RPS.
5. Median latency: 1.03 ms (Asia-Pacific), 54.7 ms (United States), 419 ms (Europe).

Conclusion

What is an RPC node? It is a blockchain node that enables dApps or wallets to interact with the blockchain. Every time a user does anything on-chain, RPC nodes work silently behind the screen to make it possible.

Aside from understanding RPC nodes, you need to be familiar with how blockchain itself works. Learn the definition of blockchain and how it works in the article What is Blockchain and How Does It Work? A Complete Guide for Beginners.