> For the complete documentation index, see [llms.txt](https://docs.lumia.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lumia.org/build-on-lumia/smart-contracts/relayers-and-meta-transactions.md).

# Relayers and meta transactions

You want a user to transact without holding the native token for gas.

**Who this is for:** developers building a gasless or "sponsored transaction" flow. **Prerequisites:** [Account Abstraction & Intents](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/ecosystem/lumia/architecture/account-abstraction-and-intents) (concept: read this first for what a smart account and paymaster are); [Networks & Endpoints](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/reference/networks-and-endpoints).

### How gasless transactions work on Lumia

Lumia's account-abstraction stack (ERC-4337: smart account, factory, EntryPoint, paymaster; see [`/lumia/architecture/account-abstraction`](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/ecosystem/lumia/architecture/account-abstraction-and-intents)) is the path that's been built and exercised as a demo on Beam testnet. A paymaster contract, **LumiaPaymaster**, is a Foundry-based reference implementation deployed per-integrator via a script, not a single shared instance you point at. See [`/reference/contract-addresses`](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/reference/contract-addresses) for the EntryPoint address and the deploy-your-own model, and [`/reference/sdks`](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/reference/sdks) for its packaging status.

This means "meta-transaction" on Lumia today is, concretely: submit a UserOperation to the EntryPoint through a bundler, with your own deployed LumiaPaymaster sponsoring gas according to whatever policy you configure (per-account, global, or a gas allowance). It is not a classic ERC-2771 trusted-forwarder relay pattern layered on top of ordinary transactions.

### Steps (paymaster-sponsored path)

{% stepper %}
{% step %}
**Deploy your own LumiaPaymaster instance**

```bash
forge script script/DeployLumiaPaymaster.s.sol --rpc-url https://beam-rpc.lumia.org --broadcast
```

{% endstep %}

{% step %}
**Fund the paymaster contract**

Fund it with native token so it can pay for the gas it sponsors.
{% endstep %}

{% step %}
**Build the UserOperation**

Build the UserOperation for the call you want sponsored, referencing the EntryPoint address from [`/reference/contract-addresses`](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/reference/contract-addresses), and your paymaster's address in the `paymasterAndData` field.
{% endstep %}

{% step %}
**Submit it to a bundler**

Submit the UserOperation to a bundler pointed at Lumia Beam.
{% endstep %}
{% endstepper %}

### Verify it worked

Look up the resulting UserOperation hash (or its included transaction hash, once bundled) on the Beam explorer (`https://beam-explorer.lumia.org/`) and confirm the sender account paid zero native-token gas out of its own balance. The paymaster's balance should have decreased instead.

### Troubleshooting

<details>

<summary>UserOperation rejected by the bundler</summary>

Confirm the EntryPoint address matches the one in [`/reference/contract-addresses`](https://app.gitbook.com/s/chmhPiVNAafGw48c4oU2/reference/contract-addresses) exactly; a stale or mistyped address is the most common cause.

</details>

<details>

<summary>Paymaster sponsorship silently not applied</summary>

Check the paymaster's own native-token balance; an empty paymaster can't sponsor gas.

</details>