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

# Sign EVM Transactions

> Sign EIP-1559 (Type 2) EVM transactions with Dynamic's Java SDK

## Overview

`DynamicEvmWalletClient::signTransaction` signs an EIP-1559 (Type 2) transaction and returns the **signed RLP hex**, ready to push directly to any JSON-RPC `eth_sendRawTransaction` endpoint. If you also want to broadcast in the same call, see [`sendTransaction`](/java/evm/send-transaction).

Reach for `signTransaction` when you need the signed payload out-of-band — co-signing, custom relayers, or batched broadcasts.

## Prerequisites

* [Created an EVM wallet](/java/evm/create-wallet)

## Build the Transaction

`EvmTransaction` is an immutable builder backed by `BigInteger` fields, so values up to `uint256` round-trip without precision loss:

```java theme={"system"}
import java.math.BigInteger;
import xyz.dynamic.waas.evm.EvmTransaction;

EvmTransaction tx = EvmTransaction.builder()
    .chainId(11155111L)                                       // Sepolia
    .nonce(BigInteger.ZERO)
    .maxFeePerGas(new BigInteger("10000000000"))              // 10 gwei
    .maxPriorityFeePerGas(new BigInteger("1000000000"))       // 1 gwei
    .gasLimit(new BigInteger("21000"))
    .to("0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB")
    .value(BigInteger.ZERO)
    .data("0x")
    .build();
```

EIP-155 replay protection comes from `chainId` (already included in EIP-1559 envelopes), so you don't need to apply the legacy `v + 2 * chainId + 8` adjustment yourself.

## Sign the Transaction

```java theme={"system"}
import xyz.dynamic.waas.evm.opts.SignTransactionOpts;

String signedRlpHex = client.signTransaction(SignTransactionOpts.builder()
    .transaction(tx)
    .walletProperties(walletProperties)
    .externalServerKeyShares(externalServerKeyShares)
    .build()
).join();

System.out.println("Signed RLP: " + signedRlpHex);
```

`signedRlpHex` is a `0x`-prefixed hex string carrying the full signed transaction envelope — pass it directly to `eth_sendRawTransaction` on any RPC.

## Broadcasting Yourself

If you don't want `sendTransaction` to manage signing for you — for example the transaction was signed on a client and your server only needs to relay it — broadcast the signed RLP with the static `EvmRpc.sendRawTransaction` helper. It needs no wallet, MPC, or key shares:

```java theme={"system"}
import xyz.dynamic.waas.evm.EvmRpc;

String txHash = EvmRpc.sendRawTransaction(
    signedRlpHex,
    "https://sepolia.infura.io/v3/<your-key>"
).join();
```

Or, if you'd rather manage the JSON-RPC client yourself, push the signed RLP through web3j directly:

```java theme={"system"}
import org.web3j.protocol.Web3j;
import org.web3j.protocol.http.HttpService;
import org.web3j.protocol.core.methods.response.EthSendTransaction;

Web3j w3 = Web3j.build(new HttpService("https://sepolia.infura.io/v3/<your-key>"));

EthSendTransaction resp = w3.ethSendRawTransaction(signedRlpHex).send();
if (resp.hasError()) {
    throw new RuntimeException("Broadcast failed: " + resp.getError().getMessage());
}
System.out.println("Transaction hash: " + resp.getTransactionHash());
```

## Common Transaction Types

### ETH Transfer

```java theme={"system"}
EvmTransaction transfer = EvmTransaction.builder()
    .chainId(1L)
    .nonce(nonce)
    .maxFeePerGas(maxFee)
    .maxPriorityFeePerGas(maxPriorityFee)
    .gasLimit(new BigInteger("21000"))
    .to("0xRecipientAddress")
    .value(new BigInteger("100000000000000000"))     // 0.1 ETH in wei
    .data("0x")
    .build();
```

### Contract Interaction

```java theme={"system"}
EvmTransaction call = EvmTransaction.builder()
    .chainId(1L)
    .nonce(nonce)
    .maxFeePerGas(maxFee)
    .maxPriorityFeePerGas(maxPriorityFee)
    .gasLimit(new BigInteger("100000"))
    .to("0xContractAddress")
    .value(BigInteger.ZERO)
    .data("0xFunctionSelector...")                   // ABI-encoded call data
    .build();
```

## Next Steps

* [Send transactions in one call](/java/evm/send-transaction)
* [Sign messages](/java/evm/sign-messages)
* [Sign typed data (EIP-712)](/java/evm/sign-typed-data)
* [Delegated access](/java/evm/delegated-access)