Optimism Documentation

OP Stack rollups post batch data to L1 as EIP-4844 blobs. To retrieve this data, op-node requires access to an L1 beacon endpoint. Run your own beacon node (Lighthouse, Lodestar, Nimbus, Prysm, or Teku) or use a third-party service like QuickNode. Pass the beacon endpoint to op-node:

--l1.beacon value                                                      ($OP_NODE_L1_BEACON)
          HTTP endpoint Address of L1 Beacon-node.

Configuring a blob archiver

Standard beacon nodes prune blobs after 18 days. If your node is synced within the last 18 days and stays online, the default beacon endpoint is sufficient. You need a blob archiver if either of these is true:

You’re syncing a new node from a snapshot or genesis older than 18 days
Your node has been offline for more than 18 days

Pass one or more fallback endpoints to op-node:

--l1.beacon-fallbacks value                                            ($OP_NODE_L1_BEACON_FALLBACKS)
          Addresses of L1 Beacon-API compatible HTTP fallback endpoints. Used to fetch blob sidecars
          not available at the l1.beacon (e.g. expired blobs).

--l1.beacon-fallbacks was previously called --l1.beacon-archiver. The old name still works as an alias, and so does the legacy env var $OP_NODE_L1_BEACON_ARCHIVER.

Choose one of these options for the archiver endpoint:

Option 1 — Run a beacon node with blob pruning disabled. For Lighthouse, set --prune-blobs=false and point --l1.beacon-fallbacks at it.
Option 2 — Run a dedicated blob archiver service such as base-org/blob-archiver, and point --l1.beacon-fallbacks at its API endpoint. Lighter weight than running a full no-prune beacon node.
Option 3 — Use a third-party blob-archiver service. Useful if you don’t want to operate any beacon infrastructure.

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Fetch blob data for your node

Configuring a blob archiver