> ## 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.
# sendSponsoredTransaction
> Send a gas-sponsored EVM transaction and wait for it to land on-chain.
`sendSponsoredTransaction` is the primary function for [EVM gas sponsorship](/docs/javascript/reference/evm/evm-gas-sponsorship). It signs an intent for a batch of calls, relays it to Dynamic's sponsorship backend, and resolves once the relay reports the transaction has been included on-chain. The user pays no gas.
EVM Gas Sponsorship is an enterprise-only feature and works with **V3 MPC embedded wallets** only. See the [Overview](/docs/javascript/reference/evm/evm-gas-sponsorship) for setup.
## Usage
```javascript theme={"system"}
import { sendSponsoredTransaction } from '@dynamic-labs-sdk/evm';
import { parseEther } from 'viem';
const { transactionHash } = await sendSponsoredTransaction({
walletAccount,
calls: [
{
target: recipientAddress, // who/what you're sending to
data: '0x', // '0x' = a plain native-token transfer
value: parseEther('0.01'),
},
],
});
console.log('Sponsored transaction confirmed:', transactionHash);
```
## Parameters
`sendSponsoredTransaction` accepts **one of two shapes**: a set of unsigned `calls` to sign and send, or a `signedTransaction` you already produced with [`signSponsoredTransaction`](/docs/javascript/reference/evm/splitting-sign-and-send).
### Signing and sending calls
| Parameter | Type | Description |
| ----------------- | ---------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `walletAccount` | `EvmWalletAccount` | The V3 MPC embedded wallet to sign and send for. |
| `calls` | `SponsoredTransactionCall[]` | The batch of calls to execute (see below). |
| `authorization` | `SignAuthorizationReturnType` (optional) | A pre-signed EIP-7702 authorization. Takes priority over `autoDelegate`. |
| `autoDelegate` | `boolean` (optional) | Whether to auto-sign an EIP-7702 authorization when the wallet isn't delegated yet. Defaults to `true`. |
| `nonce` | `bigint` (optional) | A bitmap nonce to sign the intent with. When provided, nonce generation and its on-chain check are skipped. Useful for cancel-replace. See [Reusing a nonce](/docs/javascript/reference/evm/splitting-sign-and-send#reusing-a-nonce). |
| `validForSeconds` | `number` (optional) | How long the signed intent stays valid. Defaults to `600` (10 minutes). |
Each entry in `calls` is a `SponsoredTransactionCall`:
| Field | Type | Description |
| -------- | -------- | ---------------------------------------------------------------------------------------------------------------- |
| `target` | `Hex` | The address you're sending to (a recipient or a contract). |
| `data` | `Hex` | The calldata to run on the target. Use `0x` for a plain native-token transfer. |
| `value` | `bigint` | Amount of native token (in wei) to send with the call. Use `0n` for contract calls that don't move native token. |
### Sending a pre-signed transaction
| Parameter | Type | Description |
| ------------------- | ---------------------------- | ------------------------------------------------------------------------------------------------------ |
| `signedTransaction` | `SignedSponsoredTransaction` | A payload produced by [`signSponsoredTransaction`](/docs/javascript/reference/evm/splitting-sign-and-send). |
Both shapes take an optional final `client` argument — only needed if your app runs [multiple Dynamic clients](/docs/javascript/reference/client/create-dynamic-client).
## Returns
`Promise<{ transactionHash: Hex }>` — the on-chain transaction hash, once the relay reports the transaction has been included. Under the hood the function relays the intent, then polls for up to 60 seconds (see [`waitForSponsoredTransaction`](/docs/javascript/reference/evm/splitting-sign-and-send#waitforsponsoredtransaction)).
## How it works
When you call `sendSponsoredTransaction`, the SDK:
1. Builds an EIP-712 intent describing the batch of calls and a deadline
2. Signs the intent with the user's embedded wallet (and, if delegation is needed, an EIP-7702 authorization for the wallet's EOA)
3. Relays the signed intent to Dynamic's sponsorship backend
4. Polls the relayer until the request reaches a terminal state, then returns the on-chain transaction hash
EIP-7702 delegation is what lets a relayer submit a batch of calls on the user's behalf. The user's EOA is delegated, once, to a Dynamic-operated relayer contract.
## Examples
### Batch calls (multiple actions, atomically)
A single call can carry multiple entries — they execute together, all-or-nothing. This sends two USDC transfers to two addresses in one sponsored transaction:
```javascript theme={"system"}
import { sendSponsoredTransaction } from '@dynamic-labs-sdk/evm';
import { encodeFunctionData, erc20Abi, parseUnits } from 'viem';
// USDC on Base — an ERC-20 contract with 6 decimals
const USDC_ADDRESS = '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913';
const { transactionHash } = await sendSponsoredTransaction({
walletAccount,
calls: [
{
target: USDC_ADDRESS,
value: 0n,
data: encodeFunctionData({
abi: erc20Abi,
functionName: 'transfer',
args: [recipientA, parseUnits('5', 6)], // 5 USDC
}),
},
{
target: USDC_ADDRESS,
value: 0n,
data: encodeFunctionData({
abi: erc20Abi,
functionName: 'transfer',
args: [recipientB, parseUnits('10', 6)], // 10 USDC
}),
},
],
});
```
### Reusing an authorization
Pass a pre-signed `authorization` (from [`sign7702Authorization`](/docs/javascript/reference/evm/managing-7702-delegation#sign7702authorization)) to attach an explicit EIP-7702 authorization to the transaction instead of letting the SDK sign one automatically:
```javascript theme={"system"}
import {
sign7702Authorization,
sendSponsoredTransaction,
} from '@dynamic-labs-sdk/evm';
const authorization = await sign7702Authorization({ walletAccount });
const { transactionHash } = await sendSponsoredTransaction({
walletAccount,
calls,
authorization,
});
```
## Errors
If sponsorship can't go through, `sendSponsoredTransaction` throws a `SponsorTransactionError`. There is **no silent fallback** — if it throws, the transaction did not happen.
```javascript theme={"system"}
import {
sendSponsoredTransaction,
SponsorTransactionError,
} from '@dynamic-labs-sdk/evm';
try {
const { transactionHash } = await sendSponsoredTransaction({ walletAccount, calls });
return { success: true, transactionHash };
} catch (error) {
if (error instanceof SponsorTransactionError) {
return { success: false, error: 'Gas sponsorship failed' };
}
throw error;
}
```
A `SponsorTransactionError` is thrown when the sponsorship API rejects the request, the relay reports a terminal `failure` status, the request times out after 60 seconds, or the wallet doesn't support sponsored transactions. See [Error handling](/docs/javascript/reference/evm/evm-gas-sponsorship#error-handling) for the full list.
## Related functions
* [EVM Gas Sponsorship overview](/docs/javascript/reference/evm/evm-gas-sponsorship) — setup, `calls`, and the React example
* [Splitting sign & send](/docs/javascript/reference/evm/splitting-sign-and-send) — pre-sign, relay, and poll status separately
* [Managing EIP-7702 delegation](/docs/javascript/reference/evm/managing-7702-delegation) — control the one-time delegation step