Ethereum Foundation updated EIP-8130 with corrected sentinel addresses, a standards-level fix that developers implementing this proposal should review immediately.

# EIP-8130 Sentinel Address Audit Walkthrough
# ================================================
# Step 1: Pull the updated EIP-8130 specification and identify
# the corrected sentinel address(es). Compare against your codebase.

# Example: Old (incorrect) sentinel address vs. new (corrected) value
# Replace these with the actual values from the updated EIP-8130 text.
OLD_SENTINEL = "0x0000000000000000000000000000000000000001"  # previous incorrect value
NEW_SENTINEL = "0x0000000000000000000000000000000000000042"  # corrected value per updated EIP

# Step 2: In Solidity, check if your contracts reference the old sentinel.
# Search your codebase for hardcoded sentinel addresses:
#
#   grep -rn "0x0000000000000000000000000000000000000001" contracts/
#
# If found, update the constant:
#
#   // SPDX-License-Identifier: MIT
#   pragma solidity ^0.8.24;
#
#   contract EIP8130Consumer {
#       // UPDATED per EIP-8130 fix (2026-04-15)
#       address constant SENTINEL = 0x0000000000000000000000000000000000000042;
#
#       function isSentinel(address _addr) public pure returns (bool) {
#           return _addr == SENTINEL;
#       }
#   }

# Step 3: Write a test to verify the new sentinel is recognized correctly.
#
#   // In your Foundry test file:
#   function test_sentinelAddressUpdated() public {
#       // Confirm the contract uses the corrected sentinel
#       assertTrue(consumer.isSentinel(address(0x42)));
#       // Confirm the old sentinel is no longer treated as special
#       assertFalse(consumer.isSentinel(address(0x01)));
#   }

# Step 4: For off-chain services (indexers, backends), update any
# address filtering logic:
#
#   # Python example — update your event listener filter
#   # Before:
#   # SENTINEL = "0x0000000000000000000000000000000000000001"
#   # After:
#   SENTINEL = "0x0000000000000000000000000000000000000042"
#
#   def is_sentinel_event(log_entry):
#       return log_entry["address"].lower() == SENTINEL.lower()

# Step 5: If you have immutable on-chain contracts referencing the
# old value, evaluate upgrade paths:
#   - Proxy pattern (UUPS/Transparent): update implementation
#   - No proxy: consider migration to a new deployment
#   - Document the discrepancy for downstream consumers

# Step 6: Pin your dependency on the EIP text. Bookmark the commit:
#   https://github.com/ethereum/EIPs (check EIP-8130 history)
# This ensures you track any further amendments to the proposal.