reth ships with the
optimism feature flag in several crates, including the binary, enabling support for OP Stack chains out of the box. Optimism has a small diff from the L1 EELS,
comprising of the following key changes:
- A new transaction type,
0x7E (Deposit), which is used to deposit funds from L1 to L2.
- Modifications to the
PayloadAttributesthat allow the sequencer to submit transactions to the EL through the Engine API. Payloads will be built with deposit transactions at the top of the block, with the first deposit transaction always being the "L1 Info Transaction."
- EIP-1559 denominator and elasticity parameters have been adjusted to account for the lower block time (2s) on L2. Otherwise, the 1559 formula remains the same.
- Network fees are distributed to the various fee vaults.
- ... and some other minor changes.
For a more in-depth list of changes and their rationale, as well as specifics about the OP Stack specification such as transaction ordering and more, see the documented
the L2 EL specification, and the OP Stack specification.
op-rethis currently in the alpha stage of development. It is not yet ready for production use, and therefore does not have a stable release. To run it, you must build the
op-rethbinary from source. If you do encounter any bugs during this early stage of development, please report them in an issue on the GitHub repository.
op-rethalso does not currently support OP Stack chains with legacy, pre-Bedrock state, i.e.
Optimism Goerli. This will be possible once a database migration tool for pre-Bedrock state is released, with the capability to extract the legacy state from the old
l2gethLevelDB datadir and transplant it into Reth's MDBX database.
You will need three things to run
- An archival L1 node, synced to the settlement layer of the OP Stack chain you want to sync (e.g.
- A rollup node (e.g.
- An instance of
For this example, we'll start a
Base Mainnet node.
To run Reth on Optimism, first install
op-reth via the
Makefile in the workspace root:
git clone email@example.com:paradigmxyz/reth.git && \
cd reth && \
This will install the
op-reth binary to
Next, you'll need to install a Rollup Node, which is the equivalent to the Consensus Client on the OP Stack. Available options include:
For the sake of this tutorial, we'll use the reference implementation of the Rollup Node maintained by OP Labs, the
op-node can be built from source, or pulled from a Docker image available on Google Cloud.
rethdb build tag
op-node also comes with an experimental
rethdb build tag, which allows it to read receipts directly from an L1
reth database during derivation. This can speed up sync times, but it is not required if you do not
have access to the L1 archive node on the same machine as your L2 node.
To build the
op-node with the
rethdb build tag enabled:
git clone firstname.lastname@example.org:ethereum-optimism/optimism.git && \
(cd optimism/op-service/rethdb-reader && cargo build --release) && \
cd optimism/op-node && \
go build -v -tags rethdb -o ./bin/op-node ./cmd/main.go && \
mv bin/op-node /usr/bin/op-node
This will build the
rethdb-reader dylib and instruct the
op-node build to statically link this dylib into the binary. The
op-node binary will be installed to
optimism feature flag in
op-reth adds several new CLI flags to the
--rollup.sequencer-http <uri>- The sequencer endpoint to connect to. Transactions sent to the
op-rethEL are also forwarded to this sequencer endpoint for inclusion, as the sequencer is the entity that builds blocks on OP Stack chains.
--rollup.disable-tx-pool-gossip- Disables gossiping of transactions in the mempool to peers. This can be ommitted for personal nodes, though providers should always opt to enable this flag.
--rollup.enable-genesis-walkback- Disables setting the forkchoice status to tip on startup, making the
op-nodewalk back to genesis and verify the integrity of the chain before starting to sync. This can be ommitted unless a corruption of local chainstate is suspected.
rollup.json files, which contain various configuration fields for the rollup, can be found in their node repository, under the respective L1 settlement layer's directory (
First, ensure that your L1 archival node is running and synced to tip. Then, start
op-reth with the
--rollup.sequencer-http flag set to the
Base Mainnet sequencer endpoint:
op-reth node \
--chain base \
--rollup.sequencer-http https://sequencer.base.org \
--authrpc.port 9551 \
op-reth has been started, start up the
If you opted to build the
op-node with the
rethdb build tag, this "
RPCKind" can be enabled via appending two extra flags to the
reth_db_pathis the path to the
dbfolder inside of the reth datadir, not the
mdbx.datfile itself. This can be fetched from
op-reth db path [--chain <chain-name>], or if you are using a custom datadir location via the
--datadirflag, by appending
/dbto the end of the path.