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RPC Client Usage guide

To interface with the Solana network, a client needs to construct and send JSON RPC requests to an RPC endpoint.

This guide will teach you how to use the SolanaRpcClient and send these RPC requests.

Add dependencies​

The rpc-core library provides a convenient SolanaRpcClient that implements an API to call these RPC methods and return responses.

dependencies {
    implementation("com.solanamobile:rpc-core:0.2.6")
}

Create an RPC Client​

To create an instance of a SolanaRpcClient, pass in:

  • an RPC url that the client will send requests.
  • a networkDriver used to send HTTP requests.

In this example, we construct an RPC client pointed at devnet and Ktor as a network driver:

import com.solana.rpc.SolanaRpcClient
import com.solana.networking.KtorNetworkDriver

val rpcClient = SolanaRpcClient("https://api.devnet.solana.com", KtorNetworkDriver())

Example: Fetching latest blockhash​

Calling the getLatestBlockhash method returns an RpcResponse.

  • If successful, the response result will contain a BlockhashResult.

  • If an error occured, the response will contain an RpcError.

import com.solana.rpc.SolanaRpcClient
import com.solana.networking.KtorNetworkDriver

val rpcClient = SolanaRpcClient("https://api.devnet.solana.com", KtorNetworkDriver())

val response = rpcClient.getLatestBlockhash()

if (response.result) {
    println("Latest blockhash: ${response.result.blockhash}")
} else if (response.error) {
    println("Failed to fetch latest blockhash: ${response.error.message}")
}

Example: Sending a transaction​

To submit a transaction to the RPC, use the sendTransaction method.

  • If successful, the response result will contain a transaction signature string.

  • If an error occured, the response will contain an RpcError.

import com.solana.rpc.SolanaRpcClient
import com.solana.networking.KtorNetworkDriver

val rpcClient = SolanaRpcClient("https://api.devnet.solana.com", KtorNetworkDriver())

val transaction = Transaction(/* ... */)

/* ...sign the transaction... */

val response = rpc.sendTransaction(transaction)

if (response.result) {
    println("Transaction signature: ${response.result}")
} else if (response.error) {
    println("Failed to send transaction: ${response.error.message}")
}

Next steps​

These examples are just some of the methods supported by SolanaRpcClient. Here are suggestions to continue learning:

  • Read the following guide to learn how to build Solana program instructions and transactions.
  • For a complete reference of the RPC methods supported, view the SolanaRpcClient source code and unit tests.
  • Read the Building JSON RPC requests deep dive to learn how to create requests for RPC methods that aren't immediately supported by SolanaRpcClient.