> For the complete documentation index, see [llms.txt](https://docs.lighter.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lighter.xyz/evm/interop/tokens/token-transfers/l1-and-core.md).

# L1 and Core

Transfers between Ethereum L1 and Core move ETH or an asset with an active L1 representation. For an L1-native asset, this path becomes available after Core registration. For an EVM-native asset, its L1 wrapper must also be enabled. Core-native assets cannot be transferred to L1.

See [Token linking](/evm/interop/tokens/token-linking.md) for setup and [amounts](/evm/interop/tokens/token-transfers.md#amounts) and [routes](/evm/interop/tokens/token-transfers.md#routes) for Core transfer conventions.

## L1 to Core

Call [`L1InteropManager.sendToCore(...)`](https://github.com/elliottech/lighter-contracts/blob/lighter-evm-devnet/contracts/interop/L1InteropManager.sol) on L1. The recipient is a Core master account identified by its controlling L1 address. If it does not exist, the deposit path allocates the account index and Core creates the account when processing the deposit.

```solidity
function sendToCore(
    uint32 assetIndex,
    address to,
    uint256 amount,
    RouteType routeType
) external payable;
```

`amount` is in the L1 token's smallest units and must be a nonzero multiple of the asset's L1 `tickSize`. Read the L1 configuration from `L1InteropManager.getAssetConfig(assetIndex)`. The deposit credits `amount / tickSize` [Core base units](/evm/interop/tokens/token-transfers.md#amounts) to the selected perps or spot route, subject to Core acceptance.

1. For an ERC-20, approve `L1InteropManager` to spend `amount` of the configured L1 token.
2. Call `sendToCore(...)` with the recipient's controlling L1 address. For ETH, use `assetIndex = 1` and send exactly `amount` as `msg.value`. For an ERC-20, send no ETH with the call.
3. Confirm the deposit's processing and credited amount in Core. A successful L1 receipt only confirms submission.

L1-native tokens are escrowed on L1. An EVM-native asset's L1 wrapper is burned through its selected mint gateway. `L1InteropManager` submits the deposit through `L1CoreMessaging`; applications do not call `registerDeposit(...)` directly.

This deposit path targets L1-controlled masters, not subaccounts or EVM-controlled masters. Use a supported internal Core transfer to move funds into a subaccount after depositing.

### Unaccepted deposits

If Core does not accept the full deposit, the unaccepted amount is returned to the original deposit destination through a Core-originated [**L1 Call**](/evm/interop/message-passing.md). It belongs to `to`, which may differ from the address that paid for the deposit. Follow [Core message execution on L1](/evm/interop/message-passing/l1-and-core.md#executing-core-messages-on-l1) to complete delivery once the call is ready.

## Core to L1

### Initiating a Core withdrawal

A withdrawal to L1 can be initiated in three ways, depending on the account's controller.

* **From Core.** Submit one of the following [signed transactions](/evm/signing-core-transactions.md).
  * **Withdraw (`txType = 13`).** L1-controlled Core accounts can withdraw to their controlling L1 address using only an API-key signature. No controller ECDSA signature is required.
  * **Withdraw to L1 Address (`txType = 132`).** L1-controlled or EVM-controlled Core accounts can specify an L1 recipient. This requires both an API-key signature and the EOA controller's ECDSA signature, even when withdrawing to the controller's own address.
* **From L1.** The controlling L1 address calls [`L1CoreMessaging.withdraw(...)`](/evm/interop/message-passing/l1-and-core.md#supported-requests) to withdraw to itself, or [`L1CoreMessaging.withdrawToL1Address(...)`](/evm/interop/message-passing/l1-and-core.md#supported-requests) to specify a recipient.
* **From EVM.** The controlling EVM address calls [`EvmToCoreEntrypoint.withdrawToL1Address(...)`](/evm/interop/message-passing/evm-and-core.md#evm-initiated-withdrawal-to-l1).

A contract controller cannot supply an ECDSA signature and must use its native-domain call for the explicit-recipient option. The debit account may be the controller's master account or one of its subaccounts, subject to Core authorization.

### Finalizing a Core withdrawal

Once Core accepts the withdrawal and its batch has been [executed on L1](/evm/technical-architecture.md#batch-lifecycle-and-finalization), follow [Executing Core messages on L1](/evm/interop/message-passing/l1-and-core.md#executing-core-messages-on-l1) to retrieve the call data and execute the call.


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