# Sign Transaction
To submit a transaction to the Arweave Network, it first has to be signed using a private key. The `sign()` function is meant to replicate the behavior of the `transactions.sign()` function of [`arweave-js`](https://github.com/arweaveTeam/arweave-js#sign-a-transaction), but instead of mutating the transaction object, it returns a new and signed transaction instance.
| Argument | Type | Description |
| ------------- | ------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------ |
| `transaction` | [`Transaction`](https://github.com/arweaveTeam/arweave-js#transactions) | A valid Arweave transaction instance (**without a keyfile**) |
| `options?` | [`SignatureOptions`](https://github.com/ArweaveTeam/arweave-js/blob/master/src/common/lib/crypto/crypto-interface.ts#L3) | Arweave transaction signature options |
{% hint style="info" %}
**Note:** This function requires the [`SIGN_TRANSACTION`](/api/connect.md#permissions) permission.
{% endhint %}
{% hint style="info" %}
**Note:** The `options` argument is optional, if it is not provided, the extension will use the default signature options (default salt length) to sign the transaction.
{% endhint %}
{% hint style="warning" %}
**Tip:** A better alternative to this function is using the [`arweave-js`](https://github.com/arweaveTeam/arweave-js#sign-a-transaction) `transactions.sign()` instead. Just omit the second parameter (`JWK` key) when calling the method, and [`arweave-js`](https://github.com/arweaveTeam/arweave-js#sign-a-transaction) will automatically use Wander.
{% endhint %}
{% hint style="warning" %}
**Note:** If you are trying to sign a larger piece of data (5 MB <), make sure to notify the user to not switch / close the browser tab. Larger transactions are split into chunks in the background and will take longer to sign.
{% endhint %}
## Example usage
### With `arweave-js` (recommended)
```ts
import Arweave from "arweave";
// create arweave client
const arweave = new Arweave({
host: "ar-io.net",
port: 443,
protocol: "https"
});
// connect to the extension
await window.arweaveWallet.connect(["SIGN_TRANSACTION"]);
// create a transaction
const transaction = await arweave.createTransaction({
data: 'Hello permanent world! This was signed via Wander!!!'
});
// sign using arweave-js
await arweave.transactions.sign(transaction);
// TODO: post the transaction to the network
```
### Directly using Wander
```ts
import Arweave from "arweave";
// create arweave client
const arweave = new Arweave({
host: "ar-io.net",
port: 443,
protocol: "https"
});
// connect to the extension
await window.arweaveWallet.connect(["SIGN_TRANSACTION"]);
// create a transaction
let transaction = await arweave.createTransaction({
data: 'Hello permanent world! This was signed via Wander!!!'
});
// sign using arweave-js
const signedFields = await window.arweaveWallet.sign(transaction);
// update transaction fields with the
// signed transaction's fields
transaction.setSignature({
id: signedFields.id,
owner: signedFields.owner,
reward: signedFields.reward,
tags: signedFields.tags,
signature: signedFields.signature
});
// TODO: post the transaction to the network
```
---
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