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

# Bitcoin

## Installation

Magic interacts with the Bitcoin blockchain via Magic's extension NPM package [`@magic-ext/bitcoin`](https://www.npmjs.com/package/@magic-ext/bitcoin). The Bitcoin extension also lets you interact with the blockchain using methods from [Bitcoinjs-lib](https://github.com/bitcoinjs/bitcoinjs-lib).

<Note>
  **NOTE**

  You can skip straight to our kitchen sink example directly:

  [**Bitcoin Example**](https://go.magic.link/example-bitcoin)
</Note>

<CodeGroup>
  ```bash NPM icon="npm" theme={null}
  npm install --save @magic-ext/bitcoin
  ```

  ```bash Yarn icon="yarn" theme={null}
  yarn add @magic-ext/bitcoin
  ```
</CodeGroup>

## Initialization

```js JavaScript icon="square-js" theme={null}
import { Magic } from 'magic-sdk';
import { BitcoinExtension } from "@magic-ext/bitcoin";

const magic = new Magic('YOUR_API_KEY', {
  extensions: [
    new BitcoinExtension({
      rpcUrl: 'BTC_RPC_NODE_URL',
      network: 'testnet' // testnet or mainnet
    }),
  ],
});
```

## Common Methods

### Sign Transaction

To send a standard Bitcoin blockchain transaction, you can call the `magic.bitcoin.signTransaction` method to get the signature and raw transaction then send to blockchain by yourself.

```javascript JavaScript icon="square-js" theme={null}
import { Magic } from 'magic-sdk';
import { BitcoinExtension } from "@magic-ext/bitcoin";
import * as bitcoin from 'bitcoinjs-lib'

const magic = new Magic('YOUR_API_KEY', {
  extensions: [
    new BitcoinExtension({
      rpcUrl: 'BTC_RPC_NODE_URL',
      network: 'testnet' // testnet or mainnet
    }),
  ],
});

const TESTNET = bitcoin.networks.testnet;

const tx = new bitcoin.TransactionBuilder(TESTNET);
tx.addInput('fde789dad13b52e33229baed29b11d3e6f6dd306eb159865957dce13219bf85c', 0);

tx.addOutput('mfkv2a593E1TfDVFmf1szjAkyihLowyBaT', 80000);

const txHex = tx.buildIncomplete().toHex();

const signedTransactionHex = await magic.bitcoin.signTransaction(txHex, 0);

console.log("signed transaction", signedTransactionHex);
```

## Resources

* [Bitcoin Developer Site](https://developer.bitcoin.org)