> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adamik.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Using Adamik API with Ethereum

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.

## Prerequisites

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

## Step-by-Step Guide

### 1. Setting Up the Environment

Ensure you have the `ethers` library installed in your project:

```bash theme={null}
npm install ethers
```

### 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](https://github.com/AdamikHQ/adamik-link/blob/main/test/docs/ethereum.spec.ts).

```javascript theme={null}
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();
```

### 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.

### 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.

### 5. Get in Touch

Connect with us through our [Discord Server](https://discord.gg/gsZJR2JfMR) or directly through [GitHub](https://github.com/AdamikHQ).