Backend & Scripting Applications

Back-end applications are suitable for when you need to perform actions from your wallet or simply need to read data, rather than connecting to your user's wallets.

You can build back-end applications or scripts by using any of our SDKs:

JavaScript

Python

Go

Unity

Installation

Javascript
Python
Go
Unity

npm install @thirdweb-dev/sdk ethers@5

pip install thirdweb-sdk

go get github.com/thirdweb-dev/go-sdk

https://portal.thirdweb.com/gamingkit/setting-up/installation

Instantiating the SDK

There are two different kinds of SDK instances you can create:

Read-only: Select a network and connect to it to read data from the blockchain.
Read-Write: Connect a wallet using either a private key or signer/provider and write transactions directly from the wallet.

Read-only Connection

Provide the name of the chain you want to connect to as a string.

Javascript
Python
Go
Unity

import { ThirdwebSDK } from "@thirdweb-dev/sdk";

// Create a READ-ONLY instance of the ThirdwebSDK on the Polygon network
const sdk = new ThirdwebSDK("polygon"); // configure this to your network

from thirdweb import ThirdwebSDK

# You can create new READ-ONLY instance of the SDK to use by just passing in a network name
sdk = ThirdwebSDK("mumbai")

package main

import (
	"fmt"
  
	"github.com/thirdweb-dev/go-sdk/thirdweb"
)

func main() {
	// Creates a new READ-ONLY instance of the SDK to get read-only data for your contracts, you can pass:
	// - a chain name (mainnet, goerli, polygon, mumbai, avalanche, fantom)
	// - a custom RPC URL
	sdk, err := thirdweb.NewThirdwebSDK("mumbai", nil)
	if err != nil {
		panic(err)
	}

	// Now we can interact with the SDK, like displaying the connected chain ID
	chainId, err := sdk.GetChainID()
	if err != nil {
		panic(err)
	}

	fmt.Println("New SDK instance create on chain", chainId)
}

using UnityEngine;
using Thirdweb; // 1. Import the ThirdwebSDK

public class DemoClass : MonoBehaviour
{
    // 2. Create a ThirdwebSDK instance for us to use throughout the class
    private ThirdwebSDK sdk;

    void Start()
    {
        // 3. When the app starts, set up the ThirdwebSDK
        // Below, we're setting up a read-only instance on the "goerli" test network.
        sdk = new ThirdwebSDK("goerli");
    }
}

From a Private key

This instantiates the SDK with write permissions directly from a wallet's private key.

If you expose your private key, anyone can access your wallet's funds. Please proceed carefully.

danger

Ensure you store and access your private key securely.

Check if you need to use a private key for your application.
Never directly expose your private key in your source code.
Never commit any file that may contain your private key to your source control.
Never use a private key for a frontend (website/dapp) application.

If you are unsure how to securely store and access your private key, please do not proceed.

Javascript
Python
Go
Unity

import { ThirdwebSDK } from "@thirdweb-dev/sdk";

const sdk = ThirdwebSDK.fromPrivateKey(
  // Learn more about securely accessing your private key: https://portal.thirdweb.com/sdk/set-up-the-sdk/securing-your-private-key
  "<your-private-key-here>",
  "polygon", // configure this to your network
);

from thirdweb import ThirdwebSDK
from thirdweb.types.nft import NFTMetadataInput
import os

# Learn more about securely accessing your private key: https://portal.thirdweb.com/sdk/set-up-the-sdk/securing-your-private-key
PRIVATE_KEY = "<your-private-key-here>"

# Now you can create a new instance of the SDK with your private key
sdk = ThirdwebSDK.from_private_key(PRIVATE_KEY, "mumbai")

package main

import (
    "fmt"
    "encoding/json"

    "github.com/thirdweb-dev/go-sdk/thirdweb"
)

func main() {
    // Learn more about securely accessing your private key: https://portal.thirdweb.com/sdk/set-up-the-sdk/securing-your-private-key
    privateKey := "..."

    // Instantiate the SDK with your privateKey
    sdk, err := thirdweb.NewThirdwebSDK("mumbai", &thirdweb.SDKOptions{
        PrivateKey: privateKey,
    })
    if err != nil {
        panic(err)
    }
}

// Unity does not support instantiating the SDK with a private key.

From a Signer / Provider

You can use a signer such as one from an Ethers Web3Provider to instantiate the SDK.

Javascript
Python
Go
Unity

import { ThirdwebSDK } from "@thirdweb-dev/sdk";

// Instantiate the ThirdwebSDK using the signer
// the signer variable comes from a signer you have previously created,
// or from our React SDK's useSigner hook.
const sdk = ThirdwebSDK.fromSigner(
  signer, 
  "polygon", // configure this to your network
);

from thirdweb import ThirdwebSDK

# Now you can create a new instance of the SDK with the signer.
# Here, the signer variable comes from a signer you have previously created.
sdk = ThirdwebSDK("mumbai", signer)

// NOTE: Go does not support instantiating the SDK from a signer.
package main

import (
    "fmt"
    "encoding/json"

    "github.com/thirdweb-dev/go-sdk/thirdweb"
)

func main() {
    // Get your private key securely (preferably from an environment variable)
    privateKey := "..."

    // Instantiate the SDK with your privateKey
    sdk, err := thirdweb.NewThirdwebSDK("mumbai", &thirdweb.SDKOptions{
        PrivateKey: privateKey,
    })
    if err != nil {
        panic(err)
    }
}

// Unity does not support instantiating the SDK with a signer.
// Learn how to connect users wallets to your Unity app:
// https://portal.thirdweb.com/gamingkit/setting-up/connect-wallets

Configuring Chain

If you are using one of our default chains, provide the name of the chain as a string.

View all pre-defined chains

Ethereum: "ethereum"
Goerli: "goerli"
Polygon: "polygon"
Mumbai: "mumbai"
Arbitrum One: "arbitrum"
Arbitrum Goerli: "arbitrum-goerli"
Optimism: "optimism"
Optimism Goerli Testnet: "optimism-goerli"
Binance SmartChain: "binance"
Binance SmartChain Testnet: "binance-testnet"
Fantom Opera: "fantom"
Fantom Testnet: "fantom-testnet"
Avalanche C Chain: "avalanche-fuji"
Avalanche Fuji Testnet: "avalanche-fuji-testnet"
Localhost: "localhost"

For non-default chains, import one of the 700+ chains available in the @thirdweb-dev/chains package.

You can install this package with:

npm
Yarn

npm install @thirdweb-dev/chains

yarn add @thirdweb-dev/chains

Then, import the chain you want to use and pass it as the argument, rather than a string.

import { ThirdwebSDK } from "@thirdweb-dev/sdk";
import { Gnosis } from "@thirdweb-dev/chains";

const sdk = ThirdwebSDK.fromPrivateKey(
  // Learn more about securely accessing your private key: https://portal.thirdweb.com/sdk/set-up-the-sdk/securing-your-private-key
  "<your-private-key-here>",
  Gnosis,
);

Custom Chains

If your chain is not included in the @thirdweb-dev/chains package, you can provide the chain information yourself as an object.

import { ThirdwebSDK } from "@thirdweb-dev/sdk";

const sdk = ThirdwebSDK.fromPrivateKey(
  // Learn more about securely accessing your private key: https://portal.thirdweb.com/sdk/set-up-the-sdk/securing-your-private-key
  "<your-private-key-here>",
  {
    // === Required information for connecting to the network === \\
    chainId: 59140, // Chain ID of the network
    // Array of RPC URLs to use
    rpc: ["<your-rpc-url-here>"],

    // === Information for adding the network to your wallet (how it will appear for first time users) === \\
    // Information about the chains native currency (i.e. the currency that is used to pay for gas)
    nativeCurrency: {
      decimals: 18,
      name: "Consensys ETH",
      symbol: "crETH",
    },
    shortName: "czkevm", // Display value shown in the wallet UI
    slug: "consensys", // Display value shown in the wallet UI
    testnet: true, // Boolean indicating whether the chain is a testnet or mainnet
    chain: "ConsenSys", // Name of the network
    name: "ConsenSys zkEVM Testnet", // Name of the network
  },
);

Local Nodes

If you are running a local node using a tool such as Hardhat or Anvil, provide "localhost" as the name.

You can then deploy or import your contracts to the dashboard to interact with them in your app.

Backend & Scripting Applications

JavaScript

Python

Go

Unity

Installation​

Instantiating the SDK​

Read-only Connection​

From a Private key​

From a Signer / Provider​

Configuring Chain​

Custom Chains​

Local Nodes​