block: block header (the 6 fields, unhashed) and Stacks height. The height corresponds to the Stacks block that is associated to the Bitcoin block in which the Bitcoin transaction is in.
prev-blocks: the block headers of the previous 10 blocks blocks to the one the bitcoin transaction is in. Only used in case of a flash block.
tx: The raw bitcoin transaction in bytes
proof: The proof demonstrating that the tx is in the block. tx-index, is the leaf position of the tree in the Merkle Tree. hashes, the leaves of the Merkle Tree of the transactions in the block, tree-depth: the height of the Merkle Tree.
output-index: the output in the Bitcoin transaction that we need to parse.
sender: the public key of the sender used to claim back the funds from the HTLC. The private key has to be kept by the user.