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

# Send a Sponsored Transfer

> Use a smart-account client to send from the wallet while a paymaster pays gas.

The role's key authorizes the transfer, the vault supplies the native currency,
and a paymaster contract pays the gas. A bundler submits the signed UserOperation
to EntryPoint v0.9, which validates it before Swig executes through SignV2.

Start with [Environment Setup](/evm/setup) for source setup. Use an existing compatible wallet,
or [create a wallet](/evm/create-wallet) and optionally
[add a spending role](/evm/add-role).

## Prepare the account and sponsor

Use an already deployed Swig account configured for the canonical v0.9
EntryPoint, `0x433709009B8330FDa32311DF1C2AFA402eD8D009`. The selected authority must
be a secp256k1 role or an active secp256k1 session. The wallet's permissions still
apply; sponsorship does not increase the role's allowance.

The shared beacon enables automatic fleet upgrades. It also requires a bundler
with a compatible mempool policy. Coordinate account registration with the
bundler operator before submitting. Creating a wallet alone does not register it.

Set these values alongside `RPC_URL` and `SIGNER_PRIVATE_KEY`:

| Variable | Value |
| - | - |
| `BUNDLER_URL` | RPC endpoint for the compatible bundler |
| `ACCOUNT_ADDRESS` | The deployed, registered Swig config address |
| `ROLE_ID` | Role authorizing this transfer; defaults to `0` |
| `RECIPIENT` | Transfer destination allowed by the role |
| `VALUE_WEI` | Native-currency amount; defaults to `1` |

For the limited role from these guides, use an EOA recipient with no code and a
positive amount within the remaining allowance. The vault must hold the amount.
Include no calldata for this native-transfer permission.

## Choose a TypeScript smart-account SDK

Both integrations use `toSwigSmartAccount` from the Swig SDK. The existing client
owns operation preparation, estimation, sponsorship, submission, and receipt
polling. The adapter supplies Swig's call encoding, role nonce, and signing hook.

| Client | Tested version | Example |
| - | - | - |
| Viem Bundler Client | 2.56.3 | [Viem source](https://github.com/anagrambuild/swig-protocol-sdk/blob/5eec58c3eca4b79c483d245df2f2885313fd03dc/evm/typescript/examples/send-sponsored-transfer.ts) |
| permissionless.js Smart Account Client | 0.4.1 with Viem 2.56.3 | [permissionless source](https://github.com/anagrambuild/swig-protocol-sdk/blob/5eec58c3eca4b79c483d245df2f2885313fd03dc/evm/typescript/examples/send-sponsored-transfer-permissionless.ts) |

Set `PAYMASTER_URL` to an ERC-7677-compatible sponsor endpoint supporting your
chain, account, and EntryPoint version. Both examples use Viem's standard
paymaster client. A paymaster is a contract with its own validation rules; an
arbitrary EOA address cannot serve as a paymaster.

For the TypeScript examples on the disposable local chain (`1337`), set only
`TEST_PAYMASTER_ADDRESS` and unset `PAYMASTER_URL`. Supplying both is rejected. The optional
[contributor runner](/evm/setup#try-every-scenario-locally) provisions this fixture.

From `evm/typescript`, run either client:

<CodeGroup>
  ```bash Viem theme={null}
  bun run examples/send-sponsored-transfer.ts
  ```

  ```bash permissionless.js theme={null}
  bun run examples/send-sponsored-transfer-permissionless.ts
  ```
</CodeGroup>

Each example submits a single call, checks the UserOperation's `success` field,
and prints `userOperationHash` and `transactionHash`. An included operation can
fail during wallet execution: asset movement and permission consumption revert,
but the EntryPoint nonce can be consumed and the sponsor charged. Check the
UserOperation result, not only its containing transaction receipt.

## Run the Rust and Python examples locally

The Rust and Python examples use Alloy and Web3.py/eth-account with Swig's thin
adapter. Their runnable sponsorship setup is the disposable local chain
(`1337`), using `TEST_PAYMASTER_ADDRESS`. The Rust example also uses Rundler's fee
quote. The [local runner](/evm/setup#try-every-scenario-locally) provisions these inputs
and executes both examples.

<CodeGroup>
  ```bash Rust theme={null}
  # From evm, against the configured local fixture:
  cargo run --locked -p swig-evm --example send_sponsored_transfer
  ```

  ```bash Python theme={null}
  # From evm/python, against the configured local fixture:
  uv run --locked python examples/send_sponsored_transfer.py
  ```
</CodeGroup>

To adapt the Rust or Python flow to a hosted environment, obtain fees and current
sponsorship fields through that provider's client before signing.

Full examples: [Rust](https://github.com/anagrambuild/swig-protocol-sdk/blob/5eec58c3eca4b79c483d245df2f2885313fd03dc/evm/rust/examples/send_sponsored_transfer.rs),
[Python](https://github.com/anagrambuild/swig-protocol-sdk/blob/5eec58c3eca4b79c483d245df2f2885313fd03dc/evm/python/examples/send_sponsored_transfer.py).

## Choose a compatible provider

Viem and permissionless.js pass the local v0.9 flow against unmodified Rundler
0.11.0 with an explicit account-scoped mempool exception and tracing enabled.
That SDK result does not establish acceptance by hosted Pimlico or another public
bundler. Verify the provider's account, EntryPoint, and paymaster support before
using its endpoint.

The current adapter supports sponsored operations for deployed accounts and one
call per operation. Use [direct SignV2](/evm/send-transfer) when the role's EOA
should pay gas. Self-funded ERC-4337 operations and account deployment inside a
UserOperation are outside this adapter's current scope.

For account registration and fleet-upgrade maintenance, see
[Bundler Compatibility](/evm/bundler-compatibility).