The Stellar network is preparing for one of its most significant protocol upgrades of the year as validators get ready to vote on Protocol 27, also known as the Zipper Upgrade, on July 8 at 17:00 UTC.
If approved, the upgrade will introduce new authentication capabilities for Soroban smart contracts, improve transaction efficiency, strengthen network security, and lay the foundation for future account abstraction features. The proposal follows weeks of testing and developer preparation after the upgrade successfully launched on Stellar’s Testnet in June.
According to the Stellar Development Foundation, developers, infrastructure providers, and businesses have been encouraged to update their software ahead of the Mainnet vote to ensure compatibility once Protocol 27 becomes active.
Zipper Makes Smart Accounts More Efficient
One of the biggest enhancements included in Protocol 27 is authentication delegation for custom accounts, allowing smart contract accounts to securely delegate signing authority to other addresses through a native protocol feature.
Previously, developers building smart wallets or advanced account systems on Soroban had to manually create multiple authorization entries for every delegated signer. This increased transaction sizes, complicated simulations, and added unnecessary development complexity.
With Zipper, delegated signers are bundled into a single authorization entry using a new credential type, dramatically reducing transaction size while simplifying smart account development.
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The upgrade introduces two new protocol host functions that make delegation a first-class feature rather than an engineering workaround. This creates new possibilities for wallet developers, including social recovery mechanisms, delegated signing keys, modular multisignature wallets, and more flexible account management.
The Stellar Development Foundation also notes that these improvements serve as foundational infrastructure for the future implementation of CAP-0072, which aims to bring contract-based authentication to traditional Stellar accounts.
Enhanced Security and Foundation for Future Growth
Beyond usability improvements, Protocol 27 also strengthens network security through a new credential standard known as SOROBAN_CREDENTIALS_ADDRESS_V2.
The updated credential binds a signer’s address directly into the authorization payload, eliminating a narrow replay attack scenario that could occur when multiple accounts shared private keys. While the previous credential type remains supported until Protocol 28, developers are encouraged to begin migrating to the new standard during the upcoming protocol cycle.
Importantly, the transition has been designed to minimize disruption. Existing smart contracts and credential types will continue functioning after the upgrade, giving developers a full protocol cycle to update their applications.
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The Stellar Development Foundation has also consolidated parts of its developer toolkit, encouraging projects currently using the standalone stellar-base library to migrate toward the unified stellar-sdk package as part of broader ecosystem modernization.
If validators approve the proposal, Protocol 27 will represent another significant milestone in Stellar’s long-term roadmap. While many of the changes are aimed primarily at developers, the benefits could ultimately reach end users through cheaper transactions, more secure wallets, improved account recovery options, and more sophisticated decentralized applications built on Soroban.
As blockchain networks continue competing to improve scalability and developer experience, Stellar’s Zipper Upgrade demonstrates the project’s continued focus on enterprise-ready infrastructure while expanding the capabilities available to builders across its growing ecosystem.
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