Getting Started

This guide walks you through creating your first Starknet.go application. You'll build a simple program that connects to Starknet and retrieves blockchain data.

Prerequisites

• Go 1.20 or higher installed
• Starknet.go installed in your project
• Basic understanding of Go programming

Your First Application

We'll create an application that connects to Starknet and retrieves the latest block information.

Step 1: Project Setup

Create a new directory and initialize a Go module:

mkdir my-starknet-app
cd my-starknet-app
go mod init my-starknet-app

Add Starknet.go dependency:

go get github.com/NethermindEth/starknet.go
go mod tidy

Step 2: Create the Application

Create main.go with the following code:

package main
 
import (
    "context"
    "fmt"
    "log"
 
    "github.com/NethermindEth/starknet.go/rpc"
)
 
func main() {
    // Connect to Starknet Sepolia testnet
    client, err := rpc.NewProvider("https://starknet-sepolia.public.blastapi.io/rpc/v0_8")
    if err != nil {
        log.Fatal("Failed to create client:", err)
    }
 
    // Get chain information
    chainID, err := client.ChainID(context.Background())
    if err != nil {
        log.Fatal("Failed to get chain ID:", err)
    }
 
    blockNumber, err := client.BlockNumber(context.Background())
    if err != nil {
        log.Fatal("Failed to get block number:", err)
    }
 
    fmt.Printf("Connected to Starknet\n")
    fmt.Printf("Chain ID: %s\n", chainID)
    fmt.Printf("Latest block: %d\n", blockNumber)
}

Step 3: Run the Application

go run main.go

Expected output:

Connected to Starknet
Chain ID: SN_SEPOLIA
Latest block: 1506321

Understanding the Code

RPC Client: The rpc.NewProvider() function creates a client that communicates with Starknet nodes via JSON-RPC.

Context: Go's context package manages request timeouts and cancellation. Use context.Background() for simple operations.

Error Handling: Always check for errors when making RPC calls, as network operations can fail.

Next Steps

Now that you have a basic application working, you can explore more features:

1. Client Configuration - Learn how to configure your Starknet client
2. Client Methods - Explore available methods for interacting with Starknet
3. Examples - See more examples of using Starknet.go

Troubleshooting

If you encounter any issues:

1. Make sure your Starknet node URL is correct and accessible
2. Check that you have the latest version of Starknet.go installed
3. Verify your Go version meets the minimum requirement (1.20 or higher)
4. Avoid naming your module after Go standard library packages