Running BLAST Mainnet from Source

Please follow these steps first if you have not done so already.

#Get the data directory

The next step is to download the data directory for op-geth. You will need 500+ GB for this part alone.

  1. Download the data directory snapshot. This is a large file so expect it to take some time. Bedrock Data Directory (XXGB)(opens new window)

  2. Check the validity of your download. This is an important step. Corrupted data directories will make your node fail. So ensure your checksum matches.

    sha256sum mainnet-bedrock.tar.zst
    # expected output
    ec4baf47e309a14ffbd586dc85376833de640c0f2a8d7355cb8a9e64c38bfcd1  mainnet-bedrock.tar.zst


    sha512sum mainnet-bedrock.tar.zst
    # expected output
    c17067b7bc39a6daa14f71d448c6fa0477834c3e68a25e96f26fe849c12a09bffe510e96f7eacdef19e93e3167d15250f807d252dd6f6f9053d0e4457c73d5fb mainnet-bedrock.tar.zst

  3. Create the data directory in op-geth and fill it. This will take time.

    Navigate into your op-geth directory and run these commands:

    mkdir datadir
    cd datadir
    tar xvf <<PATH_TO_DATA_DIR>>

#Create a shared secret between op-geth and op-node

  1. Navigate into your op-geth directory and run these commands:

    openssl rand -hex 32 > jwt.txt
    cp jwt.txt ../optimism/op-node

#Scripts to start the different components

In the root of your working directory create a new directory: scripts.


  1. Navigate into your scripts directory:

  2. Create a new file:

  3. Make it executable:

    chmod +x
  4. Insert this snippet of code into and modify the path to the op-geth directory.

    #! /usr/bin/bash
    cd <<Path to op-geth directory>>
    ./build/bin/geth \
      --datadir=./datadir \
      --http \
      --http.port=8545 \
      --http.addr= \
      --authrpc.addr=localhost \
      --authrpc.jwtsecret=./jwt.txt \
      --verbosity=3 \
      --rollup.sequencerhttp=$SEQUENCER_URL \
      --nodiscover \
      --syncmode=full \

Archive Nodes

You will also need to add --gcmode archive.

  1. Run the following command to start op-geth:



  1. Navigate to the scripts directory you created.

  2. Create a new file:

  3. Make it executable:

    chmod +x
  4. Insert this snippet of code into

    L1URL=<< L1 RPC URL >>
    cd <<Path to op-node directory>>
    ./bin/op-node \
        --l1=$L1URL  \
        --l1.rpckind=$L1KIND \
        --l2=ws://localhost:8551 \
        --l2.jwt-secret=./jwt.txt \
        --network=$NET \
        --rpc.addr= \
  • Change << L1 RPC URL >> to your local L1 node or a service provider's URL for the L1 node (L1 Ethereum). E.g. for Infura,

  • Set L1KIND to the network provider you are using (options: alchemy, quicknode, infura, parity, nethermind, debug_geth, erigon, basic, any).

  1. Run the following command to start bl-node:


#The initial synchronization

The datadir provided by Blast is not updated continuously, so before you can use the node you need a to synchronize it.

During that process you get log messages from bl-node, and nothing else appears to happen.

INFO [06-26|13:31:20.389] Advancing bq origin                      origin=17171d..1bc69b:8300332 originBehind=false

That is normal - it means that bl-node is looking for a location in the batch queue. After a few minutes it finds it, and then it can start synchronizing.

While it is synchronizing, you can expect log messages such as these from bl-node:

INFO [06-26|14:00:59.460] Sync progress                            reason="processed safe block derived from L1" l2_finalized=ef93e6..e0f367:4067805 l2_safe=7fe3f6..900127:4068014 l2_unsafe=7fe3f6..900127:4068014 l2_time=1,673,564,096 l1_derived=6079cd..be4231:8301091
INFO [06-26|14:00:59.460] Found next batch                         epoch=8e8a03..11a6de:8301087 batch_epoch=8301087 batch_timestamp=1,673,564,098
INFO [06-26|14:00:59.461] generated attributes in payload queue    txs=1  timestamp=1,673,564,098
INFO [06-26|14:00:59.463] inserted block                           hash=e80dc4..72a759 number=4,068,015 state_root=660ced..043025 timestamp=1,673,564,098 parent=7fe3f6..900127 prev_randao=78e43d..36f07a fee_recipient=0x4200000000000000000000000000000000000011 txs=1  update_safe=true

And log messages such as these from op-geth:

INFO [06-26|14:02:12.974] Imported new potential chain segment     number=4,068,194 hash=a334a0..609a83 blocks=1         txs=1         mgas=0.000  elapsed=1.482ms     mgasps=0.000   age=5mo2w20h dirty=2.31MiB
INFO [06-26|14:02:12.976] Chain head was updated                   number=4,068,194 hash=a334a0..609a83 root=e80f5e..dd06f9 elapsed="188.373ยตs" age=5mo2w20h
INFO [06-26|14:02:12.982] Starting work on payload                 id=0x5542117d680dbd4e

#How long will the synchronization take?

To estimate how long the synchronization will take, you need to first find out how many blocks you synchronize in a minute. You can use this Foundry (opens new window)script to get an estimated sync time.

  1. Navigate to your scripts directory

  2. Create a new file:

  3. Make it executable:

    chmod +x
  4. Insert this snippet of code into


export ETH_RPC_URL=http://localhost:8545
CHAIN_ID=`cast chain-id`
echo Chain ID: $CHAIN_ID
echo Please wait

if [ $CHAIN_ID -eq 238]; then

if [ $CHAIN_ID -eq 239]; then

T0=`cast block-number --rpc-url $ETH_RPC_URL` ; sleep 60 ; T1=`cast block-number --rpc-url $ETH_RPC_URL`
PER_MIN=`expr $T1 - $T0`
echo Blocks per minute: $PER_MIN

if [ $PER_MIN -eq 0 ]; then
    echo Not synching

# During that minute the head of the chain progressed by thirty blocks
echo Progress per minute: $PROGRESS_PER_MIN

# How many more blocks do we need?
HEAD=`cast block-number --rpc-url $L2_URL`
BEHIND=`expr $HEAD - $T1`
HOURS=`expr $MINUTES / 60`
echo Hours until sync completed: $HOURS

if [ $HOURS -gt 24 ] ; then
   DAYS=`expr $HOURS / 24`
   echo Days until sync complete: $DAYS
  1. Run the following command to get an estimate:



It is best to start op-geth first and shut it down last.

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