RPC Package

The RPC package provides direct access to Starknet's JSON-RPC API (v0.9.0 specification). Use it to query blockchain data, submit transactions, and subscribe to real-time updates.

What This Package Does

• Fetch blocks and transactions
• Read contract storage and state
• Query event logs with filters

• Deploy accounts and contracts
• Execute contract functions
• Estimate transaction fees

• Subscribe to new blocks
• Monitor contract events
• Track transaction status

Getting Started

package main
 
import (
    "context"
    "fmt"
    "log"
 
    "github.com/NethermindEth/starknet.go/rpc"
)
 
func main() {
    client, err := rpc.NewProvider("https://starknet-sepolia.public.blastapi.io/rpc/v0_8")
    if err != nil {
        log.Fatal(err)
    }
 
    blockNumber, err := client.BlockNumber(context.Background())
    if err != nil {
        log.Fatal(err)
    }
 
    fmt.Printf("Latest block: %d\n", blockNumber)
}

• WebSocket example - Real-time subscriptions
• Read events example - Event filtering
• Simple call example - Contract state reads

Core Components

Provider

HTTP client for standard RPC calls. Handles requests/responses for querying blocks, reading state, and submitting transactions.

WebSocketProvider

WebSocket client for subscriptions. Use this when you need real-time event streaming or block notifications.

Types

Type definitions for all RPC operations. Provides compile-time type safety for requests and responses.

Available Methods

Block Methods

• BlockNumber - Get latest block number
• BlockHashAndNumber - Get both hash and number
• BlockWithTxHashes - Block with transaction hashes only
• BlockWithTxs - Block with full transaction details
• BlockWithReceipts - Block with transactions and receipts
• BlockTransactionCount - Count transactions in a block
• StateUpdate - State changes in a block

• Just need the block number? Use BlockNumber()
• Want minimal data? Use BlockWithTxHashes()
• Need full transaction data? Use BlockWithTxs()
• Analyzing execution results? Use BlockWithReceipts()

Transaction Methods

• TransactionByHash - Get transaction by hash
• GetTransactionByBlockIdAndIndex - Get transaction by position
• TransactionReceipt - Get execution results
• GetTransactionStatus - Check status
• AddInvokeTransaction - Submit invoke transaction
• AddDeclareTransaction - Submit declare transaction
• AddDeployAccountTransaction - Submit deploy account transaction
• GetMessagesStatus - Check L1→L2 message status

Contract Methods

• Call - Read-only contract calls
• GetClass - Get contract class definition
• GetClassAt - Get class at address
• GetClassHashAt - Get class hash for address
• GetStorageAt - Read contract storage
• GetNonce - Get account nonce
• EstimateFee - Estimate transaction fees
• EstimateMessageFee - Estimate L1→L2 message fees
• StorageProof - Get storage Merkle proof
• CompiledCasm - Get compiled CASM class

Chain Information

• ChainID - Get chain identifier
• Syncing - Get node sync status
• SpecVersion - Get RPC spec version

Events

• Events - Query historical events (supports filtering by block range, contract address, event keys)

Debug & Tracing

• TraceTransaction - Get transaction execution trace
• TraceBlockTransactions - Trace all transactions in block
• SimulateTransaction - Simulate before sending

Network Support

Works with mainnet, testnet, and local devnets. Just change the RPC URL:

// Mainnet
mainnetClient, _ := rpc.NewProvider("https://starknet-mainnet.public.blastapi.io/rpc/v0_8")
 
// Sepolia Testnet
sepoliaClient, _ := rpc.NewProvider("https://starknet-sepolia.public.blastapi.io/rpc/v0_8")
 
// Local DevNet
devnetClient, _ := rpc.NewProvider("http://localhost:5050/rpc")

Related Packages

• Account Package - Transaction signing and sending (built on RPC)
• Client Package - Low-level JSON-RPC client
• DevNet Package - Local development utilities

Examples

• Deploy Account - Deploy a Starknet account
• Invoke Contract - Execute contract functions
• Read Events - Query and filter events
• Simple Call - Read contract state
• WebSocket - Real-time subscriptions

Reference

Implements Starknet RPC v0.9.0. Full API reference: pkg.go.dev