getTransaction3 (58)

The getTransaction3 message is a request for the full binary data of a single, specific transaction, identified by its transaction ID (TxID).

This is a more targeted version of getTransactions2 and is used when a node needs to fetch just one particular transaction.

Core Data Types

• IxiVarUInt: See IxiVarInt Encoding.
• IxiBytes: See IxiBytes Encoding.

Payload Structure

Field	Data Type	Min	Max	Description
transactionID	IxiBytes			The transaction ID (hash) of the transaction being requested.
blockNum	IxiVarUInt	0		The block number that this transaction is expected to be in. 0 if the block is unknown or the transaction is from the mempool.

Behavioral Notes

• A node sends this message to fetch a single missing transaction.
• The blockNum field provides a hint to the receiving peer about where to look for the transaction, which can optimize the lookup process (e.g., check a specific block's cache before searching the entire database).
• Upon receiving this message, a peer should find the requested transaction and send it back to the requester using a transactionData2 message.
• If the transaction is not found, no response is required.