Interact with the Smart Contract

Interacting with smart contracts on the XRPL EVM allows developers and users to execute contract functions, query data, and create seamless integrations with decentralized applications (dApps). This guide outlines how to connect to the XRPL EVM network, call smart contract functions, and manage responses using Foundry’s cast CLI, popular libraries like web3.js and ethers.js, and user-friendly interfaces such as MetaMask and Remix IDE.

Prerequisites

Before interacting with a smart contract, ensure you have the following set up:

Deployed Smart Contract
- Deploy your smart contract using the guide: Deploy a Smart Contract.
- Obtain the contract's address after deployment.
XRPL EVM Network
- Connect your wallet to the XRPL EVM using MetaMask or other compatible tools.
- Choose Mainnet or Testnet details below.

XRPL EVM Network Details

Network Name: XRPL EVM
RPC URL: https://rpc.xrplevm.org
Chain ID: 1440000
Currency Symbol: XRP
Block Explorer URL: https://explorer.xrplevm.org

Smart Contract ABI
- The Application Binary Interface (ABI) is required to interact with the contract. You can find the ABI in your contract’s build files or in Remix IDE.
Wallet Setup
- Ensure you have test XRP (XRP) for transaction fees. Use the XRPL EVM Faucet to request XRP on the appropriate network.

Interaction Methods

1. Using Remix IDE

Remix provides a simple way to interact with deployed contracts.

Steps:

Connect to XRPL EVM
- Open Remix IDE.
- Under the environment settings, select Injected Web3 to connect MetaMask.
- Make sure MetaMask is configured for either XRPL EVM Mainnet or Testnet, depending on which network you’re using.
Load the Contract
- Paste the deployed contract’s address in the Deployed Contracts section.
- Import the contract’s ABI if required.
Call Functions
- Use the Remix interface to call public or payable functions on your contract.
- MetaMask will prompt you to sign and confirm transactions.
View Results
- The response from the contract is displayed in the Remix console.

2. Using web3.js

The web3.js library provides a programmatic way to interact with smart contracts in JavaScript.

Steps:

Install web3.js
```
npm install web3
```
Connect to XRPL EVM

const Web3 = require("web3");

// XRPL EVM RPC
const web3 = new Web3("https://rpc.xrplevm.org");

// Chain ID = 1440000 (if needed in transaction config)

Load the Contract

const contractABI = [
  /* Your Contract ABI */
];
const contractAddress = "0xYourContractAddress";
const contract = new web3.eth.Contract(contractABI, contractAddress);

Call Functions

// Example: Reading a public variable
const result = await contract.methods.publicVariable().call();
console.log("Result:", result);

// Example: Sending a transaction
const receipt = await contract.methods
  .setVariable("New Value")
  .send({ from: "0xYourWalletAddress" });
console.log("Transaction Receipt:", receipt);

3. Using ethers.js

The ethers.js library is another popular option for interacting with smart contracts.

Steps:

Install ethers.js
```
npm install ethers
```
Connect to XRPL EVM

const { ethers } = require("ethers");

// XRPL EVM RPC
const provider = new ethers.providers.JsonRpcProvider(
  "https://rpc.xrplevm.org"
);
const wallet = new ethers.Wallet("0xYourPrivateKey", provider);

// Chain ID = 1440000 (if needed in transaction config)

Load the Contract

const contractABI = [
  /* Your Contract ABI */
];
const contractAddress = "0xYourContractAddress";
const contract = new ethers.Contract(contractAddress, contractABI, wallet);

Call Functions

// Example: Reading a public variable
const result = await contract.publicVariable();
console.log("Result:", result);

// Example: Sending a transaction
const tx = await contract.setVariable("New Value");
const receipt = await tx.wait();
console.log("Transaction Receipt:", receipt);

4. Frontend Interaction

Querying XRP/USD Price via the Explorer UI

Contract (Testnet-only) StdReferenceProxy Address: 0x8c064bCf7C0DA3B3b090BAbFE8f3323534D84d68

Open & Connect
- Go to the Testnet Explorer: https://explorer.testnet.xrplevm.org
- Search for the StdReferenceProxy address above and open its page.
- Click Read/Write Contract → Connect (approve in MetaMask).
Locate getReferenceData
- In the Read/Write panel, click Expand all or search for getReferenceData.
- You’ll see inputs for:
  - base (string)
  - quote (string)
Enter “XRP” and “USD”
- In base, type: XRP
- In quote, type: USD
Query the Price
- Click Read.
- The explorer will return a struct like:
```
{
  rate: 2459738388129070878,
  lastUpdatedBase: 1747305613,
  lastUpdatedQuote: 1747305684
}
```
- Interpretation:
  - rate is a ¹⁸-decimal–scaled integer.
  - To get the human-readable price, divide by 10¹⁸:
    2.459738388129070878 USD per XRP

5. Using Foundry’s `cast` CLI

Foundry’s cast tool lets you interact with your XRPL EVM contracts directly from the terminal—no JavaScript required. Below is a detailed walkthrough for reading state, sending transactions, decoding logs, estimating gas, and more, on Testnet, or Mainnet.

5.1 Prerequisites

Foundry Installed

curl -L https://foundry.paradigm.xyz | bash
foundryup

Contract Address & ABI

CONTRACT_ADDRESS=0xYourContractAddress
ABI_PATH=out/HelloWorld.json

Environment Variables (in .env, add to .gitignore):

PRIVATE_KEY=0xYOUR_PRIVATE_KEY

# Testnet
RPC_URL_TESTNET=https://rpc.testnet.xrplevm.org
CHAIN_ID_TESTNET=1449000

# Mainnet
RPC_URL_MAINNET=https://rpc.xrplevm.org
CHAIN_ID_MAINNET=1440000

Load them:

source .env

5.2 Inspect Available Functions

cast sigs $ABI_PATH

# Example output:
# message()(string)
# setMessage(string)

To get a function’s selector:

cast sig "setMessage(string)"
# → 0x368b8772

5.3 Reading State (View/Pure)

Single return:

cast call \
  --rpc-url $RPC_URL_TESTNET \
  --to      $CONTRACT_ADDRESS \
  "message()(string)"

Multiple returns:

cast call \
  --rpc-url $RPC_URL_MAINNET \
  --to      $CONTRACT_ADDRESS \
  "getStats()(uint256,address)"

5.4 Sending Transactions

Simple state change:

cast send \
  --rpc-url     $RPC_URL_TESTNET \
  --private-key $PRIVATE_KEY \
  --chain-id    $CHAIN_ID_TESTNET \
  --to          $CONTRACT_ADDRESS \
  "setMessage(string)" "Foundry rocks!"

Wait for mining:

cast send \
  --rpc-url     $RPC_URL_TESTNET \
  --private-key $PRIVATE_KEY \
  --chain-id    $CHAIN_ID_TESTNET \
  --to          $CONTRACT_ADDRESS \
  --wait        \
  "setMessage(string)" "Waiting…"

5.5 Fetching Receipts & Decoding Logs

Fetch receipt:

cast receipt \
  --rpc-url $RPC_URL_TESTNET \
  0xYourTxHash

Decode a logged event (given out/HelloWorld.json contains your ABI):

cast parse-logs \
  --abi $ABI_PATH \
  receipts.json

5.6 Gas Estimation & Fees

Estimate gas:

cast estimate-gas \
  --rpc-url $RPC_URL_MAINNET \
  --to      $CONTRACT_ADDRESS \
  "setMessage(string)" "Gas?"

Fetch gas price:

cast gas-price --rpc-url $RPC_URL_MAINNET

Calculate max fee:

EST=$(cast estimate-gas --rpc-url $RPC_URL_MAINNET --to $CONTRACT_ADDRESS "setMessage(string)" "x")
GP=$(cast gas-price --rpc-url $RPC_URL_MAINNET)
echo "Max fee (wei):" $((EST * GP))

5.7 Encoding & Decoding Data

Get calldata:

cast calldata "setMessage(string)" "Raw test"

Decode return data:

cast decode "message()(string)" 0xYourHexData

5.8 Chain & Account Utilities

Current block:

cast block-number --rpc-url $RPC_URL_TESTNET

Chain ID:

cast chain-id --rpc-url $RPC_URL_MAINNET

Balance:

cast balance --rpc-url $RPC_URL_TESTNET 0xYourWalletAddress

5.9 Sample Workflow

source .env

# 1) Read initial message on Mainnet
cast call --rpc-url $RPC_URL_MAINNET \
  --to $CONTRACT_ADDRESS "message()(string)"

# 2) Update message on Mainnet
cast send --rpc-url $RPC_URL_MAINNET \
  --private-key $PRIVATE_KEY \
  --chain-id $CHAIN_ID_MAINNET \
  --to $CONTRACT_ADDRESS \
  "setMessage(string)" "Deployed via Foundry"

# 3) Wait & fetch receipt
TX=$(cast send --rpc-url $RPC_URL_MAINNET \
  --private-key $PRIVATE_KEY \
  --chain-id $CHAIN_ID_MAINNET \
  --to $CONTRACT_ADDRESS \
  --wait \
  "setMessage(string)" "Confirmed!")
cast receipt --rpc-url $RPC_URL_MAINNET $TX

# 4) Decode any logs (if emitted)
cast parse-logs --abi $ABI_PATH receipts.json

Debugging and Testing

Use the XRPL EVM Explorer
- Access the appropriate explorer to view transaction details, logs, and contract interactions:
  - Mainnet Explorer
  - Testnet Explorer
Check Gas Fees
- Ensure sufficient XRP balance in your wallet to cover gas fees for transactions.
Debug Contract Functions
- Use the Remix IDE debugger to trace contract execution and identify issues.

Advanced Use Case: Cross-Chain Interactions

The XRPL EVM supports cross-chain functionality via Axelar General Message Passing (GMP) and Cosmos IBC. These tools allow you to:

Execute smart contract calls on other EVM or Cosmos chains.
Transfer assets seamlessly between chains.

Example

A decentralized voting dApp deployed on the XRPL EVM can fetch real-time voter statistics from Ethereum using Axelar GMP.

Next Steps

Now that you’ve learned how to interact with smart contracts, explore the following guides to enhance your development journey:

Crosschain transfers with Axelar: Send Tokens
Crosschain messages with Axelar GMP: Send Messages

Leverage the XRPL EVM’s low fees, fast transactions, and cross-chain capabilities to build innovative decentralized applications.

Interact with the Smart Contract

Prerequisites

Interaction Methods

1. Using Remix IDE

Steps:

2. Using web3.js

Steps:

3. Using ethers.js

Steps:

4. Frontend Interaction

Querying XRP/USD Price via the Explorer UI

5. Using Foundry’s cast CLI

5.1 Prerequisites

5.2 Inspect Available Functions

5.3 Reading State (View/Pure)

5.4 Sending Transactions

5.5 Fetching Receipts & Decoding Logs

5.6 Gas Estimation & Fees

5.7 Encoding & Decoding Data

5.8 Chain & Account Utilities

5.9 Sample Workflow

Debugging and Testing

Advanced Use Case: Cross-Chain Interactions

Example

Next Steps

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5. Using Foundry’s `cast` CLI