Stellar Protocol 30 'Bell' Upgrade Moves to Testnet

The Bell upgrade centers on three core improvements designated under CAP-84, CAP-87, and CAP-88. Most notably, CAP-84 introduces "muxed" smart contract addresses. By allowing a single contract to handle multiple customer balances via 64-bit identifiers, the update removes the need for businesses to deploy individual smart contracts for every user—a significant efficiency gain for exchanges and custodians. These new addresses will be distinguished by a 'W' prefix, requiring wallet providers and infrastructure operators to update their software to maintain compatibility.

Security and performance are the other pillars of the release. CAP-87 adds support for ML-DSA signature verification within Soroban smart contracts, marking the first step in Stellar’s quantum-preparedness strategy. While standard network transactions will continue to utilize Ed25519, developers can now build quantum-resistant spending controls into their smart accounts. Simultaneously, CAP-88 shifts ledger timestamps from whole-second to millisecond resolution. Although this change does not immediately reduce ledger closing times, it eliminates the technical constraints preventing faster network throughput, providing a foundation for future speed improvements.

With the testnet phase now live, the Stellar Development Foundation has released updated infrastructure software, including Stellar Core v30.0.0 and compatible SDKs. Ecosystem participants, including indexers and wallet providers, must update their systems before the November 23 mainnet vote to ensure they can correctly decode the new ledger headers and address formats.