# GetBlock

In this guide, we will walk you through the steps of using [Remix](https://remix.ethereum.org/), [MetaMask](https://metamask.io/), and [GetBlock RPC endpoints](https://getblock.io/nodes/ftm/), all of which are popular developer tools, to create and deploy a simple smart contract on Opera. Note that this tutorial will use the Opera testnet, but the steps remain the same for the mainnet.

## Requirements

Before we begin, make sure you have the following:

* MetaMask or another Web3 wallet
* Remix: An online IDE used to write, compile, deploy, and debug Solidity code
* GetBlock API key: GetBlock provides access to RPC endpoints for various blockchain networks, including Opera
  * To obtain an API key from GetBlock, register on [GetBlock.io](https://getblock.io/) and find the API key in your account
* GetBlock RPC endpoint
  * To obtain an RPC endpoint from GetBlock, register on [GetBlock.io](https://getblock.io/) and add a new endpoint by choosing Opera (*Fantom*) as the protocol and *testnet* as the network

## Create Contract

### **A) Configure MetaMask to connect to Opera using GetBlock RPC endpoints**

1. Open MetaMask and set up a custom network with the following details:
   1. Network Name: Opera Testnet
   2. New RPC URL: The GetBlock RPC endpoint you created
   3. Chain ID: Obtain the Chain ID for Opera from GetBlock documentation or API (e.g. 4002)
   4. Symbol: FTM
   5. Block Explorer URL: <https://explorer.testnet.fantom.network>

### **B) Get test tokens on the Fantom testnet**

1. Visit the [Opera Testnet Faucet](https://faucet.fantom.network/)
2. Input your MetaMask wallet address
3. Complete the CAPTCHA and request the testnet FTM

### **C) Connect Remix with the Opera network using GetBlock RPC endpoints**

1. Go to the [Remix website](https://remix.ethereum.org/#lang=en\&optimize=false\&runs=200\&evmVersion=null)
2. On the Remix home page, choose the Solidity environment
3. With the Opera network selected in MetaMask, go to Remix and click the *Deploy and Run Transactions* button on the left side, which is the fourth button
4. In the Remix environment section, select *Custom - External HTTP Provider* and enter the GetBlock RPC endpoint URL you created for Opera

### **D) Create a smart contract**

1. Click the *File Explorer* button on the left side on Remix, which is the first button
2. Right click and choose *New File* to create a new Solidity file
3. Enter the file name as "SimpleStorage.sol"
4. Copy and paste the following example Solidity code into the SimpleStorage.sol file:contract SimpleStorage {

```
    uint storedData;

    function set(uint x) public {
        storedData = x;
    }

    function get() public view returns (uint) {
        return storedData;
    }
}

```

### **E) Compile the smart contract**

1. Click the *Solidity Compiler* button on the left side, which is the third button
2. Enable auto-compile for convenience
3. Click the *Compile SimpleStorage.sol* button
4. Check for the green sign indicating successful compilation

### **F) Deploy the smart contract on the Opera testnet using Remix**

1. Click the *Deploy and Run Transactions* button on the left side, which is the fourth button
2. Select the *SimpleStorage.sol* contract from the dropdown menu
3. Click the *Deploy* button
4. Confirm the transaction in the MetaMask pop-up window
5. Once confirmed, you will see a message at the bottom right indicating the pending creation of the SimpleStorage contract
6. You can click on the transaction line or the debug button to view more details of the transaction
7. Copy the transaction hash for future reference

### **G) Use the Testnet Explorer**

1. Use the [Explorer](https://explorer.testnet.fantom.network/) to explore transactions and contracts on the Opera network
2. Paste the transaction hash into the search field at the top of the screen to view the details of your transaction

### **H) Interact with the deployed smart contract**

1. In Remix, under the *Deploy and Run Transactions* section, expand the SimpleStorage contract by clicking the > symbol
2. The orange buttons represent functions that change information on the blockchain (state changes) and require gas to execute
3. The blue buttons represent read-only functions that do not modify the blockchain and do not require gas

* Get function
  1. Click the *Get* button to retrieve the stored value, but since we have not set any value yet, it will return the default value
* Set function
  * Enter a value in the field next to the *Set* button
  * Click the *Set* button
  * Confirm the transaction in the MetaMask pop-up window
  * Wait for the transaction to be confirmed
  * After confirmation, you can check the transaction details in the bottom-right section

***

Congratulations! You have learned how to use Remix, MetaMask, and GetBlock RPC endpoints to create and deploy a smart contract on Opera.

This guide demonstrates the compatibility of Ethereum developer tools with Opera, providing you with options for building decentralized applications on both platforms.

If you have any feedback or questions, you may ask them on the [GetBlock Discord channel](https://discord.com/invite/T2hbgqfEnv).<br>


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.fantom.foundation/build-on-opera/providers/contracts/getblock.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.