Stellar activated Protocol 28 on September 17, 2026, adding batch upgrade functionality for Soroban smart contracts, data migration tools and selected consensus changes. The mainnet upgrade comes as stablecoin activity, decentralized finance and real-world asset tokenization continue to expand on the network. A scheduled mainnet vote was completed one day earlier.
Around the same time, Stellar recorded a new sustained processing mark. Blockchain data provider Chainspect measured an average of more than 211 transactions per second across 100 consecutive blocks, the network's highest sustained throughput to date. The figure should not be treated as a direct performance gain from Protocol 28, however, because Stellar is also gradually enabling parallel transaction-set downloads. The protocol upgrade is primarily designed to provide infrastructure for handling higher loads.
CAP-85 enables atomic Soroban contract upgrades
CAP-85 is aimed at protocols running multiple instances of the same smart contract. Developers can configure those contracts to reference externally managed executable code. When the shared reference changes, every contract using it can switch to the new code in a single atomic operation.
For applications that need to address security vulnerabilities or migrate software, the mechanism can reduce the period during which old and new code operate side by side. Under more traditional arrangements, different instances of the same application may run different versions for a period of time. The new contract architecture allows developers to coordinate the transition more centrally.
CAP-85 is not mandatory. Existing Soroban applications must choose whether to adopt the architecture, and any improvement in operational efficiency will depend on each development team's implementation speed and compatibility work.
CAP-86 addresses changes to contract data
CAP-86 targets another common issue for applications that have been operating on-chain for some time: stored data structures may need to change. Its new sparse-map functionality can accommodate missing or newly added fields, allowing developers to migrate data in stages rather than requiring every record to match a new schema immediately.
That capability is particularly relevant to long-running applications with large data sets. As contract fields expand or business logic changes, migration can involve a substantial volume of historical records. CAP-86 allows projects to manage those changes incrementally, but each team remains responsible for its migration plan; existing applications will not be upgraded automatically.
CAP-83 changes part of the consensus workflow
Protocol 28 also introduces consensus-layer changes through CAP-83. Under the new design, validators can continue parts of the consensus process before a transaction set has arrived in full. The network also adds mechanisms for discarding transaction sets that arrive late or prove invalid.
Stellar is still rolling out parallel transaction-set downloads. As a result, CAP-83's consensus changes cannot be directly equated with the 211 TPS record. As the related functionality is deployed, validator performance under heavy load, delayed transaction sets and invalid data will be important indicators of how the network operates in practice.
Stablecoin supply nears $884 million
The technical upgrade comes as on-chain financial activity on Stellar expands. DeFiLlama data shows that the network's stablecoin supply rose to nearly $884 million over the past year, putting Stellar among the blockchains with the larger balances of dollar-pegged assets.
The network's decentralized-finance total value locked also moved higher, reaching a temporary peak of about $319 million in August 2026 before falling back to roughly $294 million. Changes in stablecoin supply and DeFi TVL indicate that capital use on the network remains fluid. Whether Protocol 28 improves application maintenance will depend on subsequent adoption by users and projects.
Stellar's tokenized real-world asset market is larger still. Token Terminal data puts the network's RWA market value at about $3.3 billion, up approximately $149.4 million over the past 30 days. On that measure, Stellar ranks as the third-largest blockchain for tokenized real-world assets.
For applications managing large pools of tokenized assets, code fixes, contract upgrades and data-structure changes can create significant operational coordination work. CAP-85 and CAP-86 will be tested in live issuance and asset-management use cases to determine whether they reduce that burden.
XLM retreats toward $0.18 after rising
Around the activation of Protocol 28, XLM gained about 4% over 24 hours and briefly reached $0.1863 before retreating to roughly $0.18 at the time of publication. The move occurred close to the protocol launch, but there is no evidence that the upgrade directly caused the price increase.
The eventual reach of Protocol 28 will depend on how developers and validators use it. Soroban projects must actively adopt the new contract-management features, while Stellar is continuing to roll out consensus and transaction-set changes intended to support higher traffic. The timing of adoption by major asset issuers and on-chain applications will provide a clearer measure of the upgrade's practical effect on network financial activity than the launch itself.