This guide demonstrates how to create, sign, and broadcast a transaction using the Adamik API along with a common Ethereum library, ethers.js. This tutorial is perfect for developers who want to integrate Adamik’s features into their Ethereum workflows, ensuring secure and efficient transaction management.

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Prerequisites

  • Node.js and npm installed
  • Basic understanding of Ethereum and transaction workflows
  • Familiarity with the ethers.js library

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Step-by-Step Guide

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1. Setting Up the Environment

Ensure you have the ethers library installed in your project: 
npm install ethers

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2. Writing the Script

Below is the script that handles the full transaction flow, from creating a wallet to broadcasting the signed transaction. You can find the complete code example in the Adamik GitHub repository. 
import { Wallet } from "ethers";

// Replace with your wallet's mnemonic phrase
const walletPhrase = "your mnemonic phrase here";
// Replace with your Adamik API key from https://dashboard.adamik.io
const ADAMIK_API_KEY = "your-adamik-api-key";
// Replace with the recipient's address or leave empty for self-transfer
const recipientAddress = "0xeD35957be660cf9A2C768fDB52eC4D9D19eEB80F";

async function main() {
  try {
    console.log("Creating wallet...");
    const wallet = Wallet.fromPhrase(walletPhrase);

    console.log("Wallet created");
    console.log("Sender address:", wallet.address);

    const requestBody = {
      transaction: {
        data: {
          chainId: "sepolia", // Target Ethereum testnet chain
          mode: "transfer",
          senderAddress: wallet.address,
          recipientAddress: recipientAddress || wallet.address, // Self-send if no recipient
          amount: "10000", // Transaction amount
          useMaxAmount: false,
          fees: "0",
          gas: "0",
          memo: "",
          format: "json",
          validatorAddress: "",
          params: {
            pubKey: wallet.publicKey, // Public key of the wallet
          },
        },
      },
    };

    console.log("Encoding transaction...");
    // Encode the transaction with Adamik API
    const responseEncode = await fetch(
      "https://api.adamik.io/api/sepolia/transaction/encode",
      {
        method: "POST",
        headers: {
          Authorization: ADAMIK_API_KEY,
          "Content-Type": "application/json",
        },
        body: JSON.stringify(requestBody),
      }
    );

    const encodedData = await responseEncode.json();
    console.log(
      "Encoded transaction data:",
      JSON.stringify(encodedData, null, 2)
    );

    // Sign the encoded transaction
    const tx = encodedData.transaction.encoded;
    console.log("Signing transaction...");
    const signature = await wallet.signTransaction(tx);
    console.log("Transaction signed");

    // Prepare to broadcast the signed transaction
    const sendTransactionBody = {
      transaction: {
        data: encodedData.transaction.data,
        encoded: tx,
        signature: signature,
      },
    };

    console.log("Broadcasting transaction...");

    // Broadcast the transaction using Adamik API
    const responseBroadcast = await fetch(
      "https://api.adamik.io/api/sepolia/transaction/broadcast",
      {
        method: "POST",
        headers: {
          Authorization: ADAMIK_API_KEY,
          "Content-Type": "application/json",
        },
        body: JSON.stringify(sendTransactionBody),
      }
    );

    const responseData = await responseBroadcast.json();
    console.log("Transaction Result:", JSON.stringify(responseData, null, 2));
    console.log("Transaction hash:", responseData.hash);
  } catch (error) {
    console.error("Error:", error);
  }
}

main();

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3. Explanation

  • Wallet Creation: The script begins by creating a wallet using a mnemonic phrase, which is crucial for managing private keys. Please note Adamik API doesn’t have the custody of the assets.
  • Transaction Encoding: The transaction details are passed to the Adamik API, which translates them into a raw transaction to be signed.
  • Signing and Broadcasting: The transaction is then signed with the wallet’s private key and finally broadcast to the Ethereum network using the Adamik API.

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4. Troubleshooting

  • Invalid API Key: Ensure your Adamik API key is correct.
  • Network Issues: Verify network availability and Adamik API status.
  • Security Note: Never hardcode sensitive information like mnemonic phrases in your production environment.

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5. Get in Touch

Connect with us through our Discord Server or directly through GitHub.