Bitcoin Dev Kit 4.0 Launches Experimental Support for Silent Payments and BIP-353

Bitcoin Dev Kit (BDK) released version 4.0.0 of its command-line client, bdk-cli, on July 23, 2026.

The update was published by tvpeter, the project's maintainer, and includes experimental support for silent payments, DNS payment instructions, UTXO locking, and payjoin session persistence, among other improvements, according to the changelog published on GitHub.

Version 4.0.0 adds experimental support for creating silent payment transactions. This development was contributed by collaborator nymius, under request number 220. The Bitcoin Dev Kit X account details that this is one of the highlighted features of the new version.

As explained by the Criptopedia of CriptoNoticias, a silent payment allows someone to publish a single fixed address (for example, on their website or social media) and for each person sending them bitcoin to generate, from that same address, a different address on the network for each payment.

This avoids the problem of reusing an address (which allows anyone to link all payments received by that address and estimate how much money its owner handles), without the sender and receiver needing to communicate beforehand to coordinate a new address each time.

The feature implies an improvement in privacy for those receiving funds recurrently, and its experimental nature in this version means that its use with real funds is not yet recommended without proper precautions.

The update also adds support for DNS payment instructions under the BIP-353 standard. This contribution was made by collaborator sdmg15, in request #236, who debuted with this contribution in the repository.

This feature aims to replace long and hard-to-remember addresses with something similar to an email address. The practical implication is that the user would no longer have to copy and paste an extensive address every time they want to receive a payment, as long as the domain they use has that record configured.

BDK CLI 4.0.0 adds three new commands to the wallet: lock_utxo, unlock_utxo, and locked_utxos, developed by tvpeter in request #293, according to the changelog.

A UTXO (short for Unspent Transaction Output) is, in simple terms, each piece of bitcoin that a wallet has available to spend. When a payment is made, the wallet automatically chooses which of those pieces to use.

Thus, locking a UTXO means telling the wallet not to consider it when assembling a transaction, even though it is available.

This is a useful function, for example, to reserve funds intended for another purpose without the risk of accidentally spending them, or to have greater manual control over which funds are combined in a single transaction.

The new version adds payjoin session persistence, contributed by collaborator Mshehu5 in request #242. Bitcoin Dev Kit specified on X that asynchronous payjoin sessions are now stored in SQLite, allowing sessions that have been interrupted to be resumed.

Payjoin is a type of collaborative transaction in which both the sender and receiver of bitcoin contribute their own funds to the same transaction.

This serves to complicate a common chain analysis technique, which assumes that all inputs of a transaction belong to a single person; by mixing funds from both parties, that assumption becomes unreliable, providing privacy.

As this process can take time to complete (it is not instantaneous), having it now stored in an SQLite database means that if the application closes or the process is interrupted halfway, the session is not lost and can be continued later.

The project also underwent a refactoring of its internal structure, led by tvpeter, which aims to improve code readability and facilitate the incorporation of new commands, reducing the likelihood of errors, according to the changelog.

Bitcoin Dev Kit noted on X that this refactoring is also part of the highlighted changes in the version.

It is worth clarifying that the Bitcoin Dev Kit (BDK) is a set of open-source libraries, primarily written in the Rust language, designed to build secure bitcoin applications, with multiple functions and compatible with various platforms.

In other words, it is not a ready-to-use bitcoin wallet, but a set of software pieces that other developers use as a foundation to build their own applications, instead of programming all the necessary logic to handle bitcoin from scratch.