Radix Protocol Releases

Introduction

Radix names its major network releases after cities of the ancient world, and the choice turns out to be a good guide to how the network has been built. Each release is a place the protocol stopped and settled for a while, and each one added a layer the previous release had done without.

A release changes the rules that every node runs, so it cannot be adopted piecemeal. Node operators upgrade, the validator set signals readiness, and the network crosses over at a nominated epoch. Between releases, smaller protocol updates land two to three times a year; Radix documentation notes these are what other networks would call hard forks.

The line of mainnets

Olympia opened the public network in July 2021 with the node software, a desktop wallet, staking, an explorer and the native XRD token. It ran no smart contracts at all: the Radix Engine was not yet available as an execution environment for applications, so Olympia was a ledger for holding and staking rather than for building.

Alexandria followed in December 2021 and is the odd entry in the sequence, because it was not a network at all. It appended the Olympia release with a Scrypto developer environment and a local simulator, letting developers write and test against an engine that mainnet could not yet run. The library came before the city.

Babylon closed that gap on 28 September 2023, migrating from Alexandria at epoch 32,717. It brought smart contracts, the Radix Engine as a live runtime, native assets and the Radix Wallet. Babylon is the release the network is on today, and most of what this wiki documents under core concepts describes Babylon behaviour.

Xi’an is the release still ahead. It is intended to allow an unlimited number of shard groups and so put Radix’s sharded state model fully to work – the scalability half of the original design, which every release so far has deferred.

Networks that are not mainnet

Stokenet is the public test network, carrying the same protocol version as mainnet so that a blueprint proved there behaves the same when deployed. It is periodically reset, which destroys every balance, transaction and deployed package while leaving the network ID, Gateway URL and account addresses intact.

RCnet – the Radix Community Network – ran during the approach to Babylon, giving developers the tools and standards for the new engine before it reached mainnet. Stokenet superseded it.

Reading the sequence

Taken together the releases show a protocol built one layer at a time and in an unusual order: settlement first, then execution, then scale. Olympia proved the ledger, Babylon proved the engine, and Xi’an is where the sharding that motivated the whole project has to arrive. That ordering is why Radix spent a decade in research before it had smart contracts, and why the scalability claim is still the one being tested rather than the one being demonstrated.