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

# Transactions

> Build and sign transactions on Quai Network.

## Overview

Transactions are a fundamental piece of Quai Network. **Every state-changing operation within the network requires a signed transaction**.

The Quais SDK provides utilities for building and signing transactions, with support for all 3 types of transactions.

<CardGroup cols={3}>
  <Card title="Quai Transactions" icon="arrow-right" href="/sdk/content/classes/QuaiTransaction">
    EVM like transactions processed on the Quai Ledger
  </Card>

  <Card title="Qi Transactions" icon="arrow-left" href="/sdk/content/classes/QiTransaction">
    UTXO style transactions processed on the Qi Ledger
  </Card>

  <Card title="External Transactions" href="/learn/advanced-introduction/interoperability/etxs" icon="right-left">
    Either a Quai or Qi transaction moving from one zone chain to another
  </Card>
</CardGroup>

## Usage

In practice, developers will only ever need to compose Quai or Qi transactions. External transactions are created and routed automatically by the network, given the sender and reciever addresses of a given transaction.

### Quai Transaction

The [QuaiTransactionRequest](/sdk/content/type-aliases/TransactionRequest) type is used to build all types of Quai transactions. They can be signed and broadcasted to the network using a [Wallet](/sdk/content/classes/Wallet), [QuaiHDWallet](/sdk/content/classes/QuaiHDWallet), or [Signer](/sdk/content/classes/Signer).

Quai transactions are signed using [ECDSA signatures](https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm).

```ts theme={null}
const tx: QuaiTransactionRequest = {
	to: '0x0012345678901234567890123456789012345678',
	value: parseQuai('1.0'),
	data: '0x',
}

await wallet.sendTransaction(tx)
```

### Qi Transaction

The [QiTransactionRequest](/sdk/content/type-aliases/TransactionRequest) type is used to build Qi UTXO transactions. These transactions can be signed and broadcasted to the network using a [QiHDWallet](/sdk/content/classes/QiHDWallet).

Qi transactions are signed using [MuSig signatures](https://bitcoinops.org/en/topics/musig/).

<Warning>
  Qi transactions are still being developed. They are currently supported by the SDK, but are subject to change.
</Warning>

```ts theme={null}
const tx: QiTransactionRequest = {
  txInputs: [...],
  txOutputs: [...],
}

await QiHDWallet.sendTransaction(tx)
```