The introduction of Async Payjoin is being hailed as a significant development for enhancing privacy in Bitcoin transactions. Modeled closely after HTTPS, which revolutionized secure payments on the web, the Payjoin foundation has been diligently working on this privacy toolkit. Its widespread adoption is crucial for achieving privacy at scale across Bitcoin wallets.
Async Payjoin is designed to be compatible with existing Bitcoin technology, akin to the popular Bitcoin and Lightning development kits. Built with the same cryptographic principles as Bitcoin Core, it is crafted for easy integration into mainstream Bitcoin applications. The initiative echoes the success of Let’s Encrypt, which propelled HTTPS’s mass adoption in the 2010s through open-source and freely available software tools.
What sets Async Payjoin apart is its nature as a software library, unlike privacy-focused wallets such as Samourai Wallet and Wasabi. This allows any Bitcoin payment app to adopt the open standard, thereby creating a more robust privacy framework akin to HTTPS in web transactions. Referred to as Payjoin V2 by the Foundation, this new iteration enables users to engage in transactions asynchronously, a significant improvement over the earlier version that required both parties to be online.
Currently, a growing number of wallets support both versions of Payjoin standards, and the technology ensures that users with wallets not yet equipped to handle these standards can still send to Payjoin addresses and QR codes effortlessly. The foundation encourages Bitcoin privacy advocates to urge their preferred wallet providers to incorporate this open-source standard, available at Bip 77, along with a plug-and-play development kit on GitHub.
The nonprofit PayJoin Foundation, established in August 2025, aims to foster the development of open-source privacy tools. Funded by organizations such as OpenSats and Cake Wallet, it has received support from various entities dedicated to promoting privacy in the cryptocurrency space. The GitHub repository associated with Async Payjoin reflects substantial collaborative effort, boasting contributions from 37 developers on its Rust implementation.
Leading the development of the Async Payjoin protocol is Dan Gould, the executive director of the PayJoin Foundation. With a history of innovation in the Bitcoin privacy sector, Gould emphasizes the importance of sustaining this initiative without profit-driven motives, which he argues can compromise the goal of ensuring genuine privacy. The foundation has applied for 501 (c) (3) status, signaling its commitment to non-profit operations, and is actively seeking donations to support its mission.
Payjoin operates by disrupting the conventional pattern of transactions in Bitcoin, where a single input is split into two outputs—a payment and change for the sender. By utilizing multiple unspent transaction outputs (UTXOs), transactions can inadvertently link coins that were previously unrelated, reducing privacy. Payjoin addresses this issue by enabling coordination between sender and receiver, resulting in transactions that appear more complex to blockchain analysts. The process is non-custodial, ensuring that both parties maintain full control over the transaction.
Gould notes the substantial amount of information that can be exposed through typical Bitcoin transactions today, further emphasizing the need for enhanced privacy solutions. He views improvements in Bitcoin privacy as integral to the asset’s overall fungibility, a fundamental aspect of its value as a currency.
While alternative cryptocurrencies like Zcash or Monero provide inherent privacy due to encrypted transactions, they do so at the risk of complicating the validation of total coin supply and creating potential vulnerabilities. Payjoin aims to offer Bitcoin a higher level of on-chain privacy without compromising its scarcity, though widespread wallet adoption is essential for its success.
Async Payjoin introduces a significant advancement in transaction facilitation by allowing asynchronous coordination through a blinded directory server, which employs the established Oblivious HTTP standard. This ensures that users’ IP addresses remain private while maintaining the end-to-end encryption of transaction details.
Addressing concerns from regulators and exchange operators about privacy technologies, Gould asserts that compliance mechanisms can exist independently of the underlying blockchain technology. Privacy features, he argues, don’t hinder compliance but rather empower users by granting them greater control over what information they choose to share.
In summary, Async Payjoin represents a promising development in the quest for improved privacy in Bitcoin, merging the principles of open-source collaboration with robust technological advancements to create a more private and fungible currency. The foundation’s commitment to these ideals positions it as a significant player in the evolving landscape of cryptocurrency privacy.
