What is Stellar RPC? Complete Guide to the Stellar RPC API Service

The Stellar RPC API service is the primary interface for accessing real-time blockchain data on the Stellar network. As a purpose-built Stellar blockchain data API, it provides developers with JSON-RPC 2.0 endpoints for querying ledger state, simulating transactions, reading smart contract storage, and streaming events. Whether you're building payment applications, DeFi protocols, or Stellar smart contract interactions, the Stellar RPC is the foundational data layer your application needs. This guide covers everything from basic concepts to advanced production patterns used by the Stellar API for developers community.

Understanding the Stellar RPC API Service

The Stellar RPC (formerly known as Soroban RPC) was rebranded in 2026 to reflect its expanded role as the unified real-time data access layer for the entire Stellar network. Unlike the Horizon API, which focuses on historical data and deep indexing, the Stellar RPC is optimized for real-time state queries and transaction processing.

The Stellar RPC API service uses the JSON-RPC 2.0 protocol, making it compatible with standard HTTP clients in any programming language. Every request follows the same structure:

curl -X POST https://rpc.lumenquery.io \
  -H "Content-Type: application/json" \
  -H "X-API-Key: lq_your_key" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getHealth"
  }'

Core RPC Methods for Stellar Blockchain Data

The Stellar blockchain data API exposes several core methods that every developer should know. Here's a complete reference:

You can see these methods in action on our Stellar Network Analytics Dashboard, which uses getLatestLedger and Horizon endpoints to display live network metrics.

Querying Smart Contracts with the Stellar Smart Contract API

Soroban smart contracts store their state on-ledger, and the Stellar smart contract API methods let you read this data directly. The getLedgerEntries method is the primary tool for querying contract storage.

LumenQuery's Smart Contract Explorer uses these RPC methods under the hood to decode and display contract state. For a hands-on tutorial, see our guide on Soroban JSON RPC Explained.

import { Server } from '@stellar/stellar-sdk/rpc';

const rpc = new Server('https://rpc.lumenquery.io');

// Read contract storage entry
const entries = await rpc.getLedgerEntries(
  contractStorageKey(contractId, 'balance', userAddress)
);

console.log('Contract state:', entries);

Transaction Simulation: The Stellar Transaction Query API

The Stellar transaction query API includes simulateTransaction, which is essential for any application that submits transactions. It previews the result, estimates resource usage, and calculates fees—all without spending XLM. This is the same pattern used in LumenQuery's contract deployment feature.

// Simulate before submitting
const simResult = await rpc.simulateTransaction(tx);

if (simResult.error) {
  console.error('Simulation failed:', simResult.error);
} else {
  console.log('Estimated fee:', simResult.minResourceFee);
  console.log('CPU instructions:', simResult.cost?.cpuInsns);
  // Safe to sign and submit
}

Event Streaming and Real-Time Data

The getEvents method lets you query historical events emitted by smart contracts. Combined with polling, you can build real-time monitoring dashboards—like our Live Transaction Viewer which streams decoded transactions as they happen.

For detailed event streaming documentation, see the Soroban Smart Contracts Explorer docs.

Stellar RPC vs Horizon: When to Use Which

Understanding when to use the Stellar RPC vs the Horizon API is critical. For a deep dive, read our Horizon vs RPC vs Indexers comparison. The short version:

Production Best Practices for Stellar API Developers

As a Stellar API for developers platform, LumenQuery has processed millions of RPC requests. Here are the patterns that work best in production:

Getting Started with Stellar RPC

Ready to start building? LumenQuery provides managed access to the Stellar RPC API service with free tier included: