l1-l3-teleport

L1 to L3 Bridging

This tutorial shows how to bridge tokens from L1 to an Arbitrum L3.

It uses the Teleport Contracts to send ERC20 tokens through an L2's canonical token bridge, and then again through an L3's canonical token bridge. The entire process only requires a single user transaction on L1 (excluding token approval).

To bridge ETH, it uses a "double retryable", i.e. a retryable that creates another retryable.

See initiate-deposit.ts for initiating an ERC20 deposit.

See initiate-eth-deposit.ts for initiating an ETH deposit.

See monitor-deposit-status.ts for monitoring ERC20 deposits.

See monitor-eth-deposit-status.ts for monitoring ETH deposits.

Paying for retryables

When initiating an ERC20 deposit, there are multiple ways retryable fees can be paid.

There are 2 (or 3) L1 to L2 retryables and 1 L2 to L3 retryable created during a deposit. By default, the L1 to L2 retryables will be paid for in ETH when the deposit is initiated.

If the L3 uses ETH for fees, by default, the L2 to L3 retryable will be paid for in ETH when the deposit is initiated.

If the L3 uses a custom fee token that is available on L1, by default, the L2 to L3 retryable will be paid for in the fee token when the deposit is initiated. This requires an extra approval transaction.

If [the L3 uses a custom fee token] AND [it is unavailable on L1 OR skipFeeToken is passed to getDepositRequest], the L2 to L3 retryable will NOT be paid for when the deposit is initiated. If the L2 to L3 retryable is not paid for up front, it must be eventually manually redeemed on L3. Manually redeeming retryables is permissionless.

Run script:

yarn initiate-deposit --help

yarn initiate-eth-deposit --help

yarn monitor-deposit-status <txHash>

yarn monitor-eth-deposit-status <txHash>

Configure environment variables

Set the values shown in .env-sample as environmental variables. To copy it into a .env file:

cp .env-sample .env

You can also use an .env file at the root of the monorepo.