[Core Protocol] What is the current AnchorStateRegistry address for optimism mainnet?

[AdamDawidKrol]

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• Yes

Was there anything unclear or missing?

I've checked docs here but AnchorStateRegistry address for mainnet seems to be out of date (latest block stored there has 11 days. What is the current address? And in general, how can I check the current AnchorStateRegistry address without relaying on the optimism docs?

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[hash1go]

Hi! Can you clarify:

• Which AnchorStateRegistry address are you referring to as out of date?
• Which resource shows that the “latest block stored there” is 11 days old?

[AdamDawidKrol]

Address that I think is out of date: 0x1c68ECfbf9C8B1E6C0677965b3B9Ecf9A104305b.

Here https://etherscan.io/address/0x1c68ECfbf9C8B1E6C0677965b3B9Ecf9A104305b#readProxyContract I try to obtain the latest verified block (as shown on the screen).

It returns 138585637. This block is currently 13 days old (https://optimistic.etherscan.io/block/138585637). Is my reasoning correct?

[opfocus]

https://docs.optimism.io/stack/transactions/transaction-finality#steps-to-finality

[AdamDawidKrol]

@opfocus Thank you for the link. The Optimism docs you linked explain what “finality” means (i.e. a transaction is finalized once the Ethereum block containing its L2 data is itself finalized on L1) and walk through the conceptual steps to reach that state. However, they don’t explain how to query L1 to find the latest finalized block.

[hash1go]

A finalized OP Mainnet block is defined by Ethereum finality, not by the Anchor State Registry. In other words, a block is considered finalized once the blob transaction containing its data is included in an Ethereum block that itself reaches finality.

The sure-fire way to identify the latest finalized block is to run a roll-up node (op-node + op-geth) and query it as described in the official documentation.

The Anchor State Registry is unrelated to finality, and it merely records the starting point for fault-dispute games.

[AdamDawidKrol]

@hash1go But if I understand it correctly, even after an OP Mainnet block’s blob is in a finalized Ethereum block, its L2 state can still be challenged—and if the sequencer loses that dispute, here’s what happens:

The DisputeGame marks the bad output root as invalid in the AnchorStateRegistry. All L2 clients (and the sequencer) then query the registry’s stored anchor (its root and l2BlockNumber), reset their engines to that block and state, discard every block above it, and replay transactions from that exact point.

So if I want to know the state of the optimism blockchain that is 100% sure and irreversible, I need to get the state from anchored block

[hash1go]

Short answer: no, the "100% irreversible" state does not come from the AnchorStateRegistry. OP Mainnet finality is inherited from Ethereum. An L2 transaction is final when the Ethereum block carrying its L2 data in blobs is finalized on L1. Practically, because the state transition function and inputs are public, anyone running an Ethereum node plus the rollup node (op-node and op-geth) can deterministically derive the same L2 state from finalized blobs. Tracking blobs and Ethereum finality is enough to decide finality without consulting ASR.

Fault proofs can invalidate a proposed output root for withdrawals, but they do not rewrite finalized L1 inputs or create a second notion of finality. Nodes keep deriving from finalized L1 data and converge on a single canonical state. The ASR anchor only seeds future dispute games and may lag, which is expected. To fetch the latest finalized L2 block, query your node’s finalized head.