Stellar X-Ray, Protocol 25 Upgrade Guide

This guide is designed to help businesses and developers prepare for X-Ray, Protocol 25, with key dates, release information, a changelog, and more.

You can read all about what's included in X-Ray in the announcement blog and stay up to date on any and all X-Ray-related announcements on the Stellar Developer Discord, where the ecosystem coordinates and shares information about the upgrade.

• December 15, 2025: Stable releases available.
• January 7, 2026 at 2100 UTC: Testnet upgrade.
• January 22, 2026 at 1700 UTC: Mainnet upgrade vote.

Please note: This release cycle happens over the holiday period, so there is more time than usual between the availability of the stable releases and the Testnet upgrade. You can upgrade software as soon as new releases are available because they are compatible with the current protocol. However, we recognize that many people are unavailable late in the year. If you can't upgrade before the end of the year (2025), please plan to do so the first week of January in 2026.

If you use a Stellar SDK

For your Testnet integration, upgrade to the latest version of the relevant Stellar SDK before January 7, 2026. For your Mainnet integration, upgrade to the latest version of relevant Stellar SDKs before January 22, 2026.

If you run Stellar infrastructure (Stellar Core, Horizon, RPC, Galexie)

Install Protocol 25 releases. If you use Docker images, pull the Protocol 25 builds from the Docker registry. If you build from source or our Debian packages, make sure to also update your stellar-core, stellar-horizon, and stellar-rpc binaries to the Protocol 25 builds.

Ubuntu
We have published the images for Ubuntu 24.04 and Ubuntu 22.04. To build from source you can refer to the Installation Instructions for installation steps.

We have deprecated Ubuntu 20.04 (focal). Operators on Ubuntu 20.04 will need to upgrade their OS to 24.04 or 22.04. We have also switched to llvm-20. Operators using Ubuntu 22.04 will need to add the llvm-20 repositories to their systems in order to install the new packages. This step will not be required on Ubuntu 24.04. See the details in the Ubuntu Installation Instructions. Package-based installation is also described in the Stellar documentation.

Docker
We have published the Stellar Core Docker image for Protocol 25, and the Docker-based installation is also described in the Stellar documentation.

If you run a validator

The Protocol 25 upgrade vote is scheduled for January 22, 2026, at 1700 UTC. You should arm your validator with the following command:

upgrades?mode=set&upgradetime=2026-01-22T17:00:00Z&protocolversion=25

Below are up-to-date links to all available releases relevant to Protocol 25. In general, please make sure to check release notes for specific instructions and requirements, and unless otherwise indicated, opt for the “Latest Release.”

Stellar infrastructure

• Stellar Core
• Horizon
• RPC
• Galexie

SDKs

• Rust SDK
• JavaScript Base
• JavaScript SDK
• Go SDK (rpcclient & horizonclient & txnbuild)
• Java
• Python
• iOS
• PHP
• C# .NET
• Flutter
• Elixir Stellar SDK

To stay up to date on any and all X-Ray-related announcements, join the Stellar Developer Discord, where the ecosystem coordinates and shares information about the upgrade in the #protocol-next channel.

X-Ray introduces new host functions for BN254, and Poseidon and Poseidon2 permutation primitives, and does not introduce any backwards incompatibility. So there are no breaking changes in Stellar Core.

GO SDKs

• Golang SDKs (horizonclient, rpcclient, and txnbuild) are now located in a new, centralized repo - https://github.com/stellar/go-stellar-sdk.
• Go client applications that were using these SDKs from github.com/stellar/go module will need to change their project to use the new go module name github.com/stellar/go-stellar-sdk
  • Rename package import statements from github.com/stellar/go/.. to github.com/stellar/go-stellar-sdk/..