> For the complete documentation index, see [llms.txt](https://abc.bharatblockchain.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://abc.bharatblockchain.io/hedera/tutorials/file-service/create-a-file.md).

# Create a File

A transaction that creates a new file on a Hedera network. The file is referenced by its file ID which can be obtained from the receipt or record once the transaction reaches consensus on a Hedera network. The file does not have a file name. If the file is too big to create with a single `FileCreateTransaction()`, the file can be appended with the remaining content multiple times using the `FileAppendTransaction()`

## `Step 1:` Imports

* The code imports necessary modules from the Hedera JavaScript SDK (`@hashgraph/sdk`) such as `FileCreateTransaction`, `FileAppendTransaction`, `FileContentsQuery`, `TransactionRecordQuery`, `Hbar`, `LocalProvider`, and `Wallet`.
* It also imports the `fs` module from Node.js to read the contents of a file synchronously, and the `exit` method from the `process` module.

```javascript
const {
    FileCreateTransaction,
    FileAppendTransaction,
    FileContentsQuery,
    TransactionRecordQuery,
    Hbar,
    LocalProvider,
    Wallet
} = require("@hashgraph/sdk");
const fs = require('fs');
const { exit } = require("process");
```

## Step 2 : Environment Variables Retrieval and Validation

* The code loads environment variables from a `.env` file located in the `File_Service` directory using `dotenv`.
* It checks whether the required environment variables (`MY_ACCOUNT_ID` and `MY_PRIVATE_KEY`) are present. If not, it throws an error.

```javascript
require('dotenv').config({ path: 'File_Service/.env' });

if (process.env.MY_ACCOUNT_ID == null || process.env.MY_PRIVATE_KEY == null) {
    throw new Error(
        "Environment variables OPERATOR_ID, and OPERATOR_KEY are required."
    );
}
```

## Step 3 : Wallet Initialization

* It creates a new `Wallet` instance using the account ID and private key retrieved from the environment variables.
* The wallet is initialized with a `LocalProvider`, indicating that it will be used for local signing of transactions.

```javascript
const wallet = new Wallet(
    process.env.MY_ACCOUNT_ID,
    process.env.MY_PRIVATE_KEY,
    new LocalProvider()
);

```

## Step 4 : Main Function

* It reads the contents of a PDF file (`hedera.pdf`) synchronously using `fs.readFileSync()`.
* It creates a file on the Hedera network using `FileCreateTransaction`, sets the necessary parameters such as keys, contents, and transaction fee, and freezes the transaction for signing.
* The file creation transaction is then signed with the wallet's signer and executed.
* After execution, the receipt of the transaction is obtained to retrieve the new file ID.
* Data from the PDF file is appended to the created file using `FileAppendTransaction`, with similar steps for signing and execution as the file creation transaction.
* The contents of the file are retrieved using `FileContentsQuery`.
* Transaction record queries are performed to get transaction fees for both the file creation and append transactions.
* Exchange rates for the transactions are retrieved from the receipts.
* Finally, various information such as file ID, file content length, transaction fees, and exchange rates are logged to the console.

```javascript
async function main() {
    const data = fs.readFileSync('File_Service/artifacts/hedera.pdf');

    // Create a file on Hedera and store file
    let fileCreateTransaction = await new FileCreateTransaction()
        .setKeys([wallet.getAccountKey()]) 
        .setContents("")
        .setMaxTransactionFee(new Hbar(2))
        .freezeWithSigner(wallet);
    fileCreateTransaction = await fileCreateTransaction.signWithSigner(wallet);
    const txCreateResponse = await fileCreateTransaction.executeWithSigner(wallet);

    //Get the receipt of the transaction
    const createReceipt = await txCreateResponse.getReceiptWithSigner(wallet);

    //Grab the new file ID from the receipt
    const fileId = createReceipt.fileId;

    // Append data to the file
    const txAppendResponse = await (
        await (
            await new FileAppendTransaction()
                .setNodeAccountIds([txCreateResponse.nodeId])
                .setFileId(fileId)
                .setContents(data)
                .setMaxTransactionFee(new Hbar(5))
                .freezeWithSigner(wallet)
        ).signWithSigner(wallet)
    ).executeWithSigner(wallet);

    // Get the receipt of the append transaction
    const appendReceipt = await txAppendResponse.getReceiptWithSigner(wallet);

    // Get the contents of the file
    const contents = await new FileContentsQuery()
        .setFileId(fileId)
        .executeWithSigner(wallet);

    // Perform transaction record queries to get transaction fees
    const createQuery = await new TransactionRecordQuery().setTransactionId(txCreateResponse.transactionId).executeWithSigner(wallet);
    const appendQuery = await new TransactionRecordQuery().setTransactionId(txAppendResponse.transactionId).executeWithSigner(wallet);

    // Get the exchange rates
    const exchangeRateCreate = createReceipt.exchangeRate.exchangeRateInCents;
    const exchangeRateAppend = appendReceipt.exchangeRate.exchangeRateInCents;

    // Log various information
    console.log(`Your file ID is: ${fileId}`);
    console.log(`File content length according to \`FileInfoQuery\`: ${contents.length}`);
    console.log(`Fee for create: ${createQuery.transactionFee}`);
    console.log(`Fee for append: ${appendQuery.transactionFee}`);
    console.log(`Exchange Rate create (USD Cents) TX ${exchangeRateCreate}, append TX ${exchangeRateAppend}`);

    process.exit();
}

```

## Step 5 : Execution

This line calls the `main()` function to start the execution of the script.

```javascript
main();
```