Merkle Airdrop-Proof Verifier

Recomputes a Merkle airdrop-claim proof from caller-declared leaf fields (address, uint256 amount, encoding_variant) and a sibling path, OpenZeppelin MerkleProof.verify shape (processProof/_hashPair) over the already-vendored @noble/hashes keccak256 bundle -- no new vendoring, no hand-rolled hashing. Leaf derivation follows OpenZeppelin StandardMerkleTree's (address,uint256) convention: encoding_variant selects the double-hash leaf (the second-preimage-resistant default) or a single-hash variant some deployed contracts use instead, always a declared param. Sibling-pair hashing is sorted/commutative (pair_sort:true, OpenZeppelin's default) or explicit per-step left/right position (pair_sort:false), also a declared param. Given an optional claimed_path (a prior run's per-step running hashes), re-verifies and reports the earliest step at which the recompute diverges, instead of only a final match/no-match. This node never reads any chain: it cannot know whether claimed_root is the root actually recorded on-chain, whether the leaf's allocation was already claimed or redeemed, or whether the underlying tree was built correctly from the full allocation list.

Tool URL: https://ainumbers.co/chaingraph/art-605-merkle-airdrop-proof-verifier.html