Consensus
The op-alloy-consensus crate provides an Optimism consensus interface.
It contains constants, types, and functions for implementing Optimism EL
consensus and communication. This includes an extended OpTxEnvelope type
with deposit transactions, and receipts containing OP Stack
specific fields (deposit_nonce + deposit_receipt_version).
In general a type belongs in this crate if it exists in the
alloy-consensus crate, but was modified from the base Ethereum protocol
in the OP Stack. For consensus types that are not modified by the OP Stack,
the alloy-consensus types should be used instead.
Block
op-alloy-consensus exports an Optimism block type, OpBlock.
This type simply re-uses the alloy-consensus block type, with OpTxEnvelope
as the type of transactions in the block.
Transactions
Optimism extends the Ethereum EIP-2718 transaction envelope to include a deposit variant.
OpTxEnvelope
The OpTxEnvelope type is based on Alloy's
TxEnvelope type.
Optimism modifies the TxEnvelope to the following.
- Legacy
- EIP-2930
- EIP-1559
- EIP-7702
- Deposit
Deposit is a custom transaction type that is either an L1 attributes deposit transaction or a user-submitted deposit transaction. Read more about deposit transactions in the specs.
Transaction Types (OpTxType)
The OpTxType enumerates the transaction types using their byte identifier,
represents as a u8 in rust.
Receipt Types
Just like op-alloy-consensus defines transaction types,
it also defines associated receipt types.
OpReceiptEnvelope defines an Eip-2718 receipt envelope type
modified for the OP Stack. It contains the following variants - mapping
directly to the OpTxEnvelope variants defined above.
- Legacy
- EIP-2930
- EIP-1559
- EIP-7702
- Deposit
There is also an OpDepositReceipt type, extending the alloy receipt
type with a deposit nonce and deposit receipt version.
Hardforks
Aside from transactions and receipts, op-alloy-consensus exports
one other core primitive called Hardforks.
Hardforks provides hardfork transaction constructors - that is, it provides methods that return upgrade transactions for each hardfork. Some of these are the following.