New version of Bitcoin Core 25.0 reduces the minimum size per transaction

The new version of Bitcoin Core 25.0, the main software for Bitcoin network nodes, is now available. This includes improvements in terms of the use of the P2P network, in the minimum size of transactions and RPC systems.

One of the most notable improvements is related to transactions in the mempool and the retransmission policy. From now on, transactions with a minimum size of 65 bytes are allowed. This means that they will be able to make smaller transactions, which opens up new possibilities and strengthens protections against potential vulnerabilities. However, this could open the door to new BRC-20 tokens, which make use of the smallest transactions in Bitcoin, as reported by CriptoNoticias.

Regarding RPCs (Remote Procedure Call), the function scanblocks. This RPC allows obtaining the blockhashes relevant from a set of descriptors, scanning the blockfilters in a certain range. This functionality can be combined with other RPC to perform quick wallet scans.

Regarding the updated RPCs, a new parameter called args to all JSON-RPC methods. This parameter allows you to pass positional parameter values ​​more conveniently, without having to name each value individually. This simplifies the command syntax and makes it easier to use in both the Python testing framework and the “bitcoin-cli” tool.

the PRC sendrawtransaction adds a new optional argument called maxburnamoun“. This argument allows you to specify a maximum value for unexpendable outputs (UTXO). Those transactions that contain outputs with a value greater than maxburnamount they will not be sent. This change provides greater control over transactions and avoids sending transactions unwished.

In addition, improvements were made to other RPCs, such as testmempoolaccept and decodescript, which provide more information on fees and transaction sizes. In addition, there are improvements to the ability to infer descriptors from Miniscript to spend using P2WSH.

In the new update, as described in the document, more than 80 developers participated in the different stages of creation of this new version.

In this version, no controversial updates were added, as was the case in version 24.0, in which the Full RBF feature was activated. This allows each transaction found in the Bitcoin mempool to be considered as replaceable by fee (Full RBF). Months before, a great controversy broke out around the relevance of this incorporation.