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 ERC-20 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. You can read more about retryable tickets here.

See initiate-deposit.ts for initiating an ERC-20 deposit.

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

See monitor-deposit-status.ts for monitoring ERC-20 deposits.

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

Paying for retryables

When initiating an ERC-20 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 gas 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 gas token] AND [that token 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. See instructions here to manually redeem a retryable ticket.

Set environment variables

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

cp .env-sample .env

You'll still need to edit some variables, i.e., PRIVATE_KEY, CHAIN_RPC, PARENT_CHAIN_RPC and L1_RPC.

Note that you can also set the environment variables in an .env file in the root of the monorepo, which will be available in all tutorials.

Run

yarn initiate-deposit --help

yarn initiate-eth-deposit --help

yarn monitor-deposit-status <txHash>

yarn monitor-eth-deposit-status <txHash>