Introduction
What is Immutable Sequencing?
Immutable sequencing means Facet's transaction ordering is determined entirely by Ethereum L1, with no intermediaries. Users send transactions to an immutable address, and Facet blocks mirror the exact order that Ethereum includes them.
How Sequencing Works
1. User Submits Transaction
Users send Ethereum transactions containing Facet transaction data to:
0x00000000000000000000000000000000000face7
2. L1 Inclusion
Ethereum validators include these transactions in L1 blocks, just like any other Ethereum transaction. The transaction can face the same censorship risks as any L1 transaction, but benefits from Ethereum's censorship resistance.
3. Facet Block Construction
Facet nodes:
Monitor every Ethereum block
Extract all transactions sent to
0xface7
Construct Facet blocks using the exact same order as they appear in the L1 block
Apply a deterministic mapping: L1 block N → Facet block N
4. Guaranteed Inclusion
If your transaction makes it into Ethereum block 20,000,000, it will appear in Facet block 20,000,000. No sequencer or admin can change this.
Transaction Ordering Rules
Within each Facet block:
Transactions are ordered exactly as they appear in the corresponding L1 block
If L1 block has transactions at positions 42, 87, and 203 going to
0xface7
, they appear in that exact order in the Facet blockNo reordering, no prioritization, no MEV extraction by sequencers
Key Properties:
Deterministic: Given an L1 block, anyone can derive the exact Facet block
Immutable: The inbox address is an EOA, not a contract—no upgrade mechanism exists
Permissionless: Anyone who can get a transaction into L1 can get a transaction into Facet
Why EOA Instead of Smart Contract?
Traditional rollups use smart contracts for their inbox, which enables:
Disabling forced inclusion via upgrade
Changing gas metering parameters
Adding censorship logic
Facet uses 0x00..00face7
, an EOA with no known private key:
Cannot be upgraded
Cannot implement logic
Cannot discriminate between transactions
Will accept transactions forever
Comparison
Transaction ordering
Sequencer decides
L1 block order
Inbox type
Smart contract (upgradeable)
EOA (immutable)
MEV extraction
Sequencer captures value
Goes to L1 validators
Censorship resistance
Depends on sequencer/admins
Same as Ethereum
Block time
1-2 seconds
12 seconds (L1 blocks)
Trade-offs
By inheriting L1's sequencing:
Slower blocks: 12 seconds instead of 2
Higher submission costs: Full L1 transaction fees
No soft confirmations: Must wait for L1 inclusion
In exchange:
Truly unstoppable: If Ethereum lives, Facet lives
No sequencer MEV: Value flows to L1 validators
Perfect L1 alignment: State transitions match L1 blocks
Last updated