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EVMcrispr

@crypto:merkle.root

Compute the Merkle root of an array of bytes32 leaves. A single-leaf tree has root = leaf.

Returns: bytes32

Syntax

Section titled “Syntax”
@crypto:merkle.root(leaves mode?)

Arguments

Section titled “Arguments”
NameTypeDescription
leavesarrayArray of bytes32 leaves, in tree order
[mode]stringPair hashing mode: sorted (default, OpenZeppelin MerkleProof convention) or unsorted (positional, e.g. Hop transfer roots)

Examples

Section titled “Examples”
# Compute the Merkle root of a set of leaves (sorted pairs, OpenZeppelin convention)
set $leaves [0x1111111111111111111111111111111111111111111111111111111111111111 0x2222222222222222222222222222222222222222222222222222222222222222 0x3333333333333333333333333333333333333333333333333333333333333333]
print "Root:" @crypto:merkle.root($leaves)


# Compute a Hop transfer root: positional (unsorted) tree of transferIds — a single-transfer batch has root = transferId
set $transferId 0x234fe879ff0c72a91cb174831cc3eb9477813cea707dc07774ab4272db54d4e3
print "Transfer root:" @crypto:merkle.root([$transferId] "unsorted")

Notes

Section titled “Notes”
  • sorted mode hashes each pair in ascending order, so proofs verify with OpenZeppelin's MerkleProof.verify and no positional data. The tree layout matches SimpleMerkleTree from @openzeppelin/merkle-tree for the same leaf order (the OZ library additionally sorts leaves by default — pre-sort them to reproduce those roots exactly).
  • unsorted mode hashes pairs positionally (left ++ right) and pairs a trailing odd node with itself; verification folds the leaf index one bit per sibling, like Optimism/Hop Lib_MerkleTree.verify.
  • The leaves are used as-is: hash them first (e.g. with @id or @abi.encodePacked) if they are not already bytes32 digests.

See Also

Section titled “See Also”