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Wait for caffeination height before starting Espresso batcher#367

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philippecamacho merged 9 commits intocelo-integration-rebase-14.2from
ag/batcher-timestamp
Mar 20, 2026
Merged

Wait for caffeination height before starting Espresso batcher#367
philippecamacho merged 9 commits intocelo-integration-rebase-14.2from
ag/batcher-timestamp

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@QuentinI QuentinI commented Mar 5, 2026

Block batcher startup until the L2 unsafe head reaches CaffeinationHeightL2, preventing the batcher from submitting blocks below the caffeination threshold. The block loader also clamps its start range to the caffeination height so pre-caffeination blocks are never enqueued.

Closes https://app.asana.com/1/1208976916964769/project/1209976130071762/task/1213545066241809

This PR:

Makes espresso-mode batcher respect CaffeinationHeightL2 - it will not start posting before the chain reaches that height

This PR does not:

Change anything else

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gemini-code-assist bot commented Mar 5, 2026

Summary of Changes

Hello, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the Espresso batcher's operational logic by introducing a "caffeination height" mechanism. This ensures that the batcher only becomes active and processes blocks once the underlying L2 chain has reached a specified block height. This change prevents the batcher from interacting with or submitting blocks that are considered too early in the chain's progression, thereby aligning its behavior with specific chain state requirements.

Highlights

  • Batcher Startup Control: The Espresso batcher's startup is now blocked until the L2 unsafe head reaches a configured CaffeinationHeightL2, preventing it from submitting blocks below this threshold.
  • Block Loading Range Adjustment: The block loader's starting range for enqueuing blocks is clamped to CaffeinationHeightL2, ensuring that blocks prior to this height are never processed.
  • New Configuration Parameter: A new configuration parameter, CaffeinationHeightL2, has been introduced to specify the required L2 block height for the Espresso batcher to begin operation.

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Changelog
  • op-batcher/batcher/driver.go
    • Introduced a call to waitForCaffeinationHeight to ensure the L2 chain reaches the specified height before the batcher registers.
  • op-batcher/batcher/espresso.go
    • Modified nextBlockRange to clamp the starting block number for enqueuing to CaffeinationHeightL2, preventing pre-caffeination blocks from being processed.
    • Implemented waitForCaffeinationHeight function, which actively polls the L2 sync status and blocks the batcher's operation until the L2 unsafe head reaches the configured CaffeinationHeightL2.
  • op-batcher/batcher/service.go
    • Introduced CaffeinationHeightL2 field to the BatcherConfig struct to store the required L2 block height for batcher activation.
    • Configured CaffeinationHeightL2 during the initialization of the Espresso batcher service.
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Code Review

This pull request introduces a mechanism to delay the Espresso batcher startup until the L2 chain reaches a configurable CaffeinationHeightL2. This is achieved by adding a waiting loop at the beginning of the batcher startup process and clamping the block loading range to respect this height. The changes are logical and well-implemented. I have one suggestion to improve the polling logic in waitForCaffeinationHeight to avoid an unnecessary initial delay.

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jjeangal commented Mar 17, 2026

One comment I thought about when reviewing this PR is that liveness can be broken by hardcoding the caffeinated height in the config to a very high value. This would prevent the batcher from posting anything and is a value that we don't include or planned to include in the enclave hash measurement.

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QuentinI commented Mar 18, 2026 •
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liveness can be broken by hardcoding the caffeinated height in the config to a very high value

@jjeangal can't one just not run the batcher at all if they wanted to? Enclave operator can always break liveness.

@QuentinI QuentinI force-pushed the ag/batcher-timestamp branch from 304daab to 13385d3 Compare March 18, 2026 11:38
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jjeangal commented Mar 18, 2026

liveness can be broken by hardcoding the caffeinated height in the config to a very high value

@jjeangal can't one just not run the batcher at all if they wanted to? Enclave operator can always break liveness.

Yes that is true, just thinking out loud!

philippecamacho
philippecamacho reviewed Mar 19, 2026
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LGTM

Note: I added some unit tests and have them run in CI.

philippecamacho
philippecamacho approved these changes Mar 19, 2026
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LGTM

QuentinI
QuentinI commented Mar 20, 2026
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@QuentinI QuentinI Mar 20, 2026

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@philippecamacho this is unnecessary, all espresso tests are run by integration tests job and all batcher tests are run by vanilla OP pipeline in CircleCI.

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@philippecamacho philippecamacho Mar 20, 2026 •
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Ok, removed in 6e54181.

Base automatically changed from ag/move-batch-auth-to-derivation-pipeline to celo-integration-rebase-14.2 March 20, 2026 11:51
@QuentinI QuentinI force-pushed the ag/batcher-timestamp branch from 4ea8191 to 8d9a97e Compare March 20, 2026 12:04
QuentinI and others added 9 commits March 20, 2026 16:27
@QuentinI @philippecamacho
Wait for caffeination height before starting Espresso batcher
a68f1ff 
Block batcher startup until the L2 unsafe head reaches CaffeinationHeightL2,
preventing the batcher from submitting blocks below the caffeination threshold.
The block loader also clamps its start range to the caffeination height so
pre-caffeination blocks are never enqueued.

Co-authored-by: OpenCode <noreply@opencode.ai>
@QuentinI @philippecamacho
Gemini's suggestions
3686395
@philippecamacho
Add unit tests for the op-batcher related to espresso behaviour
94e274d
@philippecamacho
Run unit tests in CI.
3ede791
@philippecamacho
Fix CI
0c3235f
@philippecamacho
Simplify test
39fe6d8
@philippecamacho
Fix lint errors
c67c48d
@philippecamacho
Add command to fix linting errors.
1602e97
@philippecamacho
Remove redundant github actions workflow
74db6fc
@philippecamacho philippecamacho merged commit 88a929e into celo-integration-rebase-14.2 Mar 20, 2026
46 of 47 checks passed
@philippecamacho philippecamacho deleted the ag/batcher-timestamp branch March 20, 2026 20:16
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@QuentinI @jjeangal @philippecamacho