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Span batches encode a span of consecutive L2 blocks in a single batch, reducing the overhead of batch submission. This is especially beneficial for sparse, low-throughput chains. The format was introduced in the Delta network upgrade, and chains opt into it through the op-batcher configuration. For background on what span batches are and why they exist, see Span batches.

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Before you begin

Span batches are only valid once the Delta upgrade is active on your chain. The op-node derivation pipeline drops any span batch whose L1 origin predates Delta activation, logging dropping span batch before Delta activation.
Do not enable span batches on the batcher before Delta is active on your chain. Verifier nodes will drop the span batches your batcher posts, so the data you pay to submit will not advance the safe chain.

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Enable span batches

1

Confirm Delta is active on your chain

Delta activation is recorded as delta_time in your chain’s rollup configuration (the rollup.json file passed to op-node). Delta is active once delta_time is set and the L2 block timestamp has passed that value.You can read it from the rollup configuration file directly, or query a running op-node:
If the result is a timestamp in the past, Delta is active. If it is null, Delta is not scheduled on your chain and must be activated first. For new chains, the l2GenesisDeltaTimeOffset deploy configuration parameter schedules Delta relative to genesis (0 activates it at genesis) — see the rollup deployment configuration reference. For Delta activation times on OP Mainnet and OP Sepolia, see Network upgrades.
2

Set the batch type on op-batcher

The op-batcher --batch-type flag (environment variable OP_BATCHER_BATCH_TYPE) selects the batch format: 0 for singular batches (the default) and 1 for span batches.Set it to 1 and restart the batcher:
or, as an environment variable:
Optionally, --max-blocks-per-span-batch (OP_BATCHER_MAX_BLOCKS_PER_SPAN_BATCH) caps the number of L2 blocks added to a single span batch. The default is 0, which means no maximum. See the batcher configuration reference for details on both flags.
3

Verify the batcher configuration

On startup, the batcher logs its channel configuration. Check the Initialized channel-config log line and confirm it reports batch_type=1:

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Revert to singular batches

Singular batches remain valid after Delta, so you can switch back at any time by setting --batch-type=0 (or unsetting OP_BATCHER_BATCH_TYPE, since 0 is the default) and restarting the batcher.

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Next steps