EIP-4844 Blob Transactions Failing on Sepolia After Fusaka Upgrade

[iteyelmp]

Ethers Version

6.15

Search Terms

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Describe the Problem

After the Fusaka upgrade on Sepolia, sending EIP-4844 transactions fails with the error:

legacy blob tx is not supported

After investigation, it seems that the way blob proofs are computed has changed. Previously, we used compute-blob-kzg-proof, but now it seems we should use compute_cells_and_kzg_proofs.

However, the output of compute_cells_and_kzg_proofs is no longer a single hex string—it returns an array of arrays. This raises a question: do the blob-related fields in the transaction format need to be updated to reflect this new structure?

Requesting clarification or guidance on how EIP-4844 transactions should be constructed post-Fusaka on Sepolia.

Code Snippet

Contract ABI

Errors

Environment

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Environment (Other)

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[ricmoo]

That’s a great question. I wasn’t aware of this change. I’ll reach out to the Geth team to find out. :)

If anyone else has any feedback, that is welcome too. :)

[lightclient]

Yes, with Fusaka / EIP-7594 blob txs have a different proof format for tx submission. Each blob must be accompanied by cell proofs as defined in the EIP. Geth will create / convert the proofs when you submit a tx with eth_sendTransaction or eth_fillTransaction, but not for eth_sendRawTransaction. I assume you are using the later based on the error message, which comes from adding a blob tx to the mempool with the old format.

[ricmoo]

Thanks for the EIP number. Yes, it is for transaction serialization, so I’ll get those changes in for the next minor bump that is coming out soon. :)