Hello,

We plan to migrate two frequently used helper functions that many dapps and infra tools call indirectly through the Arbitrum SDK from the NodeInterface contract (invoked via eth_call) to native RPC methods. This change is part of a broader architectural cleanup in Nitro that removes the last circular dependency between the consensus and execution layers. This simplification will eventually make execution clients easier to test, scale, and maintain. Below are the names of the two affected NodeInterface methods and their new replacements.

• getL1Confirmations → arb_getL1Confirmations
• findBatchContainingBlock → arb_findBatchContainingBlock

How this might affect you even if you have never used these 2 methods directly?

Most builders use the Arbitrum SDK, which wraps these methods under higher-level functions. If you rely on any of the SDK calls below, you are already using the soon-to-be-replaced methods. The format is “SDK class/object → Functions affected that use NodeInterface”:

• ChildTransactionReceipt → getBatchConfirmations() , getBatchNumber(), isDataAvailable()
• ChildTransaction → getBatchConfirmations() , getBatchNumber()

What stays the same?

• Functionality and return values remain identical.
• We will run both versions in parallel for an extended sunset period (exact timeline TBD) so there won’t be breaking changes overnight.

What changes for different roles?

• Node operators and RaaS teams will need to expose the two new RPC methods.
• SDK & backend services that currently rely on the NodeInterface versions will need to upgrade to a forthcoming SDK release that calls the new RPCs.
• Front‑end dApps that invoke these helpers directly via eth_call will eventually need to switch to new RPC endpoints.

What we need from you?

If you can share with us feedback by answering this short form by Aug 7th, it’d be greatly appreciated so we can lock the migration timeline. Thanks for your feedback and let us know if any question or comment.