TL;DR
- Stellar is preparing Protocol 28, known as Adapter, with changes focused on Soroban smart contracts and network performance.
- The upgrade introduces tools for coordinated contract updates and smoother data migrations, making application maintenance easier for developers.
- Validators are scheduled to vote on testnet activation on August 27 and mainnet activation on September 16, putting the next few weeks in focus for developers and infrastructure providers.
Stellar (XLM) is approaching another significant protocol change as developers and validators prepare for Adapter, or Protocol 28. The upgrade targets Soroban, Stellar’s smart contract platform, while also introducing improvements intended to strengthen performance as on-chain applications become more complex. Stellar’sprotocol upgrades are decided through validator voting rather than a centralized deployment process.
Stellar Protocol 28, Adapter, is on the way.
This upgrade introduces enhancements that make it easier to write smart contracts on Stellar, as well as a change under the hood that helps the network reach consensus faster as it continues to scale.
What this upgrade includes 
pic.twitter.com/OOSCA6i8Mp
— Build on Stellar (@BuildOnStellar) August 13, 2026
Stellar Prepares For Soroban-Focused Changes
Adapter brings several changes aimed at reducing friction for developers managing smart contracts. CAP-85 focuses on atomic upgrades for groups of contracts that share executable code, allowing developers to update the common reference rather than handling every contract independently. CAP-86 addresses contract data migrations, an important consideration as applications evolve without forcing disruptive redesigns.
The upgrade also builds on Stellar’s broader effort to make Soroban more practical for financial applications. Recent protocol work has targeted network efficiency, including improvements to Soroban state management in Protocol 26. Stellar’s development ecosystem also includes dedicated contract SDKs and tooling for builders working with Soroban.
Another relevant change concerns authentication. Protocol 28 introduces AddressV2, replacing the older Soroban address credential format and giving developers time to migrate applications and dependencies before the transition. The change is part of Stellar’s continuing effort to improve the infrastructure supporting smart contract applications on the network.
Key Dates Put Developers On Notice
The upgrade schedule now becomes particularly important. August 13 marked the core stable release, while infrastructure and SDK releases are scheduled during the August 13–21 window. The testnet vote is set for August 27 at 17:00 UTC, giving validators and developers an opportunity to evaluate the proposed changes before mainnet activation.
The mainnet vote is scheduled for September 16 at 17:00 UTC. Activation depends on validatorapproval, so the date represents a planned governance milestone rather than a guaranteed launch. Developers running SDK-based integrations should update their dependencies and test their applications ahead of the respective voting dates.