Remote Procedure Calls (RPCs) enable one program to communicate with another across a network as if calling a local function. They are essential in both distributed computing and blockchain development. They simplify complex interactions, enabling fast, secure, and reliable communication between systems.
Whether you’re building decentralized apps (dApps), interacting with smart contracts, or developing Web3 platforms, understanding how RPCs work is key to creating efficient and scalable applications.
In this guide, we’ll explore RPCs, how they work, and why they’re indispensable in blockchain development. From querying blockchain data to deploying smart contracts, RPCs are the backbone of Web3 innovation. Let’s dive in and unlock their potential.
What are RPCs?
At their core, RPCs enable a client program to invoke a function on a remote server as a local procedure. This abstraction hides the messy details of network communication—think of it as a magic trick that makes distributed systems feel seamless. In distributed computing, RPCs have been a cornerstone for decades. In blockchain, they’re the key to interacting with nodes, querying data, and executing transactions.
How RPCs Work
Here’s the high-level process:
- Client Request: The client calls a function, passing parameters as needed.
- Stub Magic: A local “stub” (a proxy) serializes the request into a format suitable for network transmission.
- Transport: The request travels over a protocol like TCP or HTTP to the remote server.
- Server Execution: The server deserializes the request, executes the function, and prepares a response.
- Return Trip: The result is sent back to the client, again via the stub, and delivered as if it were a local result.
💡 Behind this simplicity lies a symphony of components—stubs, marshaling, and transport protocols—working together to ensure reliability and efficiency.
RPCs in Blockchain
In blockchain development, RPCs are the backbone for interacting with nodes. They allow dApps to:
- Query blockchain data (e.g., balances, block info)
- Send transactions: Transfer tokens or trigger smart contract actions.
- Interact with smart contracts: Call functions or monitor events.
Depending on their performance and scalability needs, developers can use public RPC nodes (free but slower) or private nodes (faster, more reliable).
A quick comparison table:
| Feature | JSON-RPC | gRPC |
| Format | Text-based (JSON) | Binary (Protocol Buffers) |
| Performance | Moderate | Faster (Up to 10x) |
| Complexity | Easier to Implement | More complex |
| Security | Custom implementation | Built-in TLS support |
| Streaming | Basic | Bi-directional |
- JSON-RPC: Great for small projects due to its simplicity and ease of use. Ethereum’s JSON-RPC API is a primary source for its specs.
- gRPC: Ideal for high-performance, real-time, and large-scale blockchain applications. Check gRPC’s official documentation for details.
RPC Operations in Blockchain
Blockchain Data Access
RPCs (Remote Procedure Calls) allow dApps to access blockchain data and conduct transactions. By sending structured requests to blockchain nodes, dApps can interact with the blockchain efficiently. These nodes handle the requests and provide decentralized access to the network, making executing a wide range of commands possible.
Common RPC Commands
In blockchain systems, RPC commands are grouped based on their purpose. Here’s a breakdown:
| Command Type | Purpose | Common Use Cases |
| Query commands | Retrieve blockchain data | Checking account balances, transaction history |
| Transaction commands | Submit new transactions | Sending tokens, interacting with smart contracts |
| Network commands | Get network details | Viewing node status, block height, gas prices |
| Contract commands | Work with smart contracts | Calling functions, monitoring events |
💡Each category supports specific tasks that make blockchain interactions seamless.
RPC Nodes: The Backbone of Blockchain Communication
RPC nodes handle all your requests, transactions, and smart contract interactions.
- Public endpoints: Free to use but can be slower and rate-limited.
- Private endpoints: Offer faster speeds, reliability, and often enhanced security.
Understanding and managing RPC nodes is essential for building robust blockchain applications that remain true to decentralization.
Building with RPCs
JSON-RPC Basics
JSON-RPC uses JSON to structure requests and responses. Each request includes keys like method, params, and id.
Here’s an example of a JSON-RPC request to check an Ethereum balance:
{
“jsonrpc”: “2.0”,
“method”: “eth_getBalance”,
“params”: [“0x742d35Cc6634C0532925a3b844Bc454e4438f44e”, “latest”],
“id”: 1
}
Ethereum’s official docs provide a complete list of methods here.
gRPC Implementation
gRPC leverages HTTP/2 and Protocol Buffers to deliver faster and more efficient communication. It’s beneficial for decentralized applications that deal with large amounts of data. Some of its standout features include:
| Feature | Advantage | Example Use case |
| HTTP/2 Transport | Lower latency and efficient multiplexing | Real-time communication in blockchain systems |
| Protocol Buffers | Faster serialization (3–10x faster) | High-volume data handling |
| Bi-directional Streaming | Real-time updates | Live blockchain data feeds |
Explore gRPC’s capabilities in its official guides.
JSON-RPC vs gRPC
Choosing between JSON-RPC and gRPC depends on your project’s requirements. Below is a comparison to help you decide:
| Aspect | JSON-RPC | gRPC |
| Format | Text-based(JSON) | Binancy(Protocol Buffers) |
| Performance | Moderate | Up to 10x faster |
| Complexity | Easier to implement | More complex |
| Security | Custom implementations | Built-in TLS support |
| Streaming | Basic | Bi-directional |
JSON-RPC is a dependable option for smaller projects or those prioritizing simplicity and compatibility. On the other hand, gRPC is ideal for performance-critical systems requiring high-speed data processing. Testing both in your environment can clarify which protocol better suits your needs.
RPC Examples in Web3
Ethereum Network Connection
To set up an RPC connection to the Ethereum network, you’ll need to configure your development environment with the right tools and endpoints. Here’s an example using Web3.js:
const Web3 = require(‘web3’);
const web3 = new Web3(‘your_rpc_endpoint’);
async function checkConnection() {
const blockNumber = await web3.eth.getBlockNumber();
console.log(`Connected to block: ${blockNumber}`);
}
If you’re using MetaMask and want to add a custom RPC network, you’ll need to provide the following details:
| Setting | Example Value |
| Network Name | Ethereum Mainnet |
| RPC URL | https://your-rpc-endpoint |
| Chain ID | 1 |
| Currency Symbol | ETH |
| Block Explorer | https://etherscan.io |
💡Once connected, you can use JSON-RPC methods to fetch blockchain data.
Reading Blockchain Data
To interact with the Ethereum blockchain, you can use JSON-RPC methods to retrieve key information. Here’s how to get started:
// Get account balance
const balance = await web3.eth.getBalance(‘0x742d35Cc6634C0532925a3b844Bc454e4438f44e’);
console.log(`Balance in ETH: ${web3.utils.fromWei(balance, ‘ether’)}`);
// Get block information
const block = await web3.eth.getBlock(‘latest’);
console.log(`Latest block: ${block.number}`);
Some common operations include:
| Operation | Method | Description |
| Get Balance | eth_getBalance | Returns an account’s balance in wei |
| Get Block | eth_getBlockByNumber | Retrieves details of a specific block |
| Get Tx | eth_getTransactionByHash | Fetches details of a transaction |
These methods allow you to access blockchain data for various purposes, such as tracking balances or analyzing transactions.
Sending Blockchain Transactions
When sending transactions, it’s essential to estimate gas costs and handle errors effectively. Here’s an example of deploying a smart contract called Multiply7:
const transaction = {
from: senderAddress,
to: null, // Contract deployment
data: contractBytecode,
gas: await web3.eth.estimateGas({ data: contractBytecode })
};
const receipt = await web3.eth.sendTransaction(transaction);
console.log(`Contract deployed at: ${receipt.contractAddress}`);
To ensure smooth transaction functionality, follow these best practices:
- Estimate gas costs before sending a transaction.
- Use the transaction receipt to monitor its status.
- Implement error handling and retry logic for failed transactions.
Always maintain multiple RPC endpoints for production environments to avoid disruptions caused by endpoint downtime.
RPC Usage Guidelines
Choosing an RPC Provider
When choosing an RPC provider, focus on performance and reliability. Here are some important factors to consider:
| Selection Criteria | Why it matters | Impact |
| Uptime & Reliability | Aim for 99.9%+ uptime | Keeps your application consistency available |
| Security Features | Includes private API keys, rate limiting | Protect against unauthorized access |
| Chain | Supports your target | Ensures smooth integration |
| Performance metric | Covers response times, request limits | Directly impacts user experience |
| Cost structure | Usage based vs. Flat fee | Affect scalability and budget planning |
For enterprise applications, look for providers offering dedicated support, advanced security measures, and private API keys. After selecting a provider, secure your RPC endpoints by following best practices for public RPC security.
Securing Public RPC Endpoints
Protecting public RPC endpoints is critical. Use these strategies:
- Rate Limiting
- Set request limits to prevent abuse.
- Regularly monitor for unusual activity.
- Data Protection
- Store API keys securely in environment variables, not in client-side code.
- Implement error handling to avoid exposing sensitive system details.
Once your endpoints are secure, shift focus to optimizing RPC performance.
Optimizing RPC Performance
To maximize efficiency, consider these approaches:
- Request Optimization
- Combine multiple operations into a single request.
- Cache frequently accessed data.
- Use pagination for handling large datasets.
- Infrastructure Management
- Use load balancing across multiple RPC nodes to enhance performance.
- Real-time Data Handling
- Switch to WebSocket connections for frequent updates instead of repeated HTTP requests.
Here are some additional strategies to improve performance:
| Strategy | Implementation | Benefit |
| Request Bundling | Combine queries | Reduce network overhead |
| Data Caching | Cache frequently used | Speeds up response times |
| Load Balancing | Spread traffic across nodes | Boost reliability |
| Comprehension | Minimize data size | Saves bandwidth |
| Websockets | Use for real-time updates | Avoids polling inefficiencies |
💡Always monitor performance, test bottlenecks, and prepare fallbacks to ensure your dApp stays online.
Final Thoughts
RPCs play a critical role in decentralized systems, bridging seamless communication between applications and blockchains. They ensure smooth data exchange across blockchains and Web3 platforms, essential for maintaining strong network performance and compatibility.
For developers working on Web3 projects, RPCs bring several clear advantages:
- Simplified Access: Streamline blockchain integration
- Cost Savings: Lower operational expenses
- Cross-platform use: Easy function across systems
- Better security: Safer data transmission
RPCs aren’t just technical tools—they’re the connective tissue of Web3. Mastering them puts you in control of the future of decentralized development.