The Fujiwara Testnet: SORA's Gateway to the Nexus Era

Fujiwara isn’t just another blockchain testnet—it’s the proving ground where SORA’s most ambitious vision becomes reality. Named after Japan’s influential Fujiwara clan, known for their centuries of political resilience and strategic adaptation, this testnet represents the first public testnet implementation of SORA’s v3 Hub Chain architecture on Hyperledger Iroha 2—laying the groundwork for SORA Nexus, the next-generation system being developed on Iroha 3.

While most testnets serve as simple sandboxes for testing smart contracts, Fujiwara is testing something far more significant: infrastructure designed to let central banks, enterprises, and DeFi protocols coexist on a single network. The architecture being validated here could power everything from CBDCs and savings bonds to permissionless decentralized exchanges.

TL;DR

• Fujiwara is the public testnet for SORA v3’s Hub Chain, built on Hyperledger Iroha 2. It validates concepts that will inform SORA Nexus, the successor architecture on Iroha 3.
• The testnet validates hub chain architecture concepts intended to enable CBDCs, enterprise applications, and open DeFi to coexist on one network. Sub-second (~1s) finality is a Nexus design target informed by Fujiwara testing.
• Community validators can participate now via the validator guide, helping stress-test consensus and governance mechanisms.
• The block explorer is live, offering real-time visibility into network performance and validator activity.

From Polkadot to Iroha: Understanding SORA’s Evolution

SORA’s journey to the Nexus architecture follows a deliberate evolution through three major versions, each building on lessons learned from the previous.

SORA v1 began as an experimental economic system exploring decentralized governance and tokenomics. SORA v2 expanded this vision by building on Substrate, integrating with the Polkadot ecosystem via parachain strategy, and enabling cross-chain bridges to Ethereum.

However, the team recognized that the blockchain landscape’s fragmentation—thousands of L1s, L2s, parachains, and rollups competing for liquidity and developers—wasn’t the future. Rather than continuing to add complexity through more chains, SORA chose a fundamentally different path.

SORA v3 represents that new direction. The current phase—tested on Fujiwara—runs on Hyperledger Iroha 2 as a Hub Chain prototype. SORA Nexus, the next evolution, is being developed on Iroha 3 with a single logical ledger designed to host unlimited data spaces with unbounded horizontal scalability. This isn’t an incremental upgrade—it’s a ground-up reimagining of what blockchain infrastructure should be.

For a deep dive into the complete Nexus architecture, see our SORA Nexus Complete Guide.

What Is Fujiwara Testing?

The Fujiwara testnet validates the core components that distinguish SORA Nexus from its predecessors. Understanding what’s being tested reveals why this matters for the broader blockchain ecosystem.

Hyperledger Iroha Infrastructure

Fujiwara runs on Hyperledger Iroha 2. SORA Nexus, the successor architecture, is being developed on Iroha 3 as that platform matures. Fujiwara validates Hub Chain concepts that inform Nexus design. Iroha 3 will provide the deterministic execution environment, modular consensus, and governance primitives that central banks and regulated institutions require.

Unlike general-purpose blockchain frameworks, Iroha was designed specifically for permissioned financial infrastructure—making it ideal for a network that must serve both regulated and permissionless applications simultaneously.

Hub Chain Architecture Validation

The testnet validates SORA’s vision of a unified hub chain: one network designed to connect external blockchains through governed connectors while hosting native applications. This contrasts with bridge-heavy approaches that fragment liquidity and introduce security vulnerabilities.

Community validators running Fujiwara nodes help stress-test the consensus mechanism under realistic conditions, identifying edge cases before mainnet deployment.

Transaction Fee Model Design

SORA’s team is designing a transaction fee model specifically optimized for institutional attractiveness. Unlike networks where fee volatility makes costs unpredictable, Nexus aims for the kind of fee predictability that central banks and enterprises need for production deployments.

The Fujiwara testnet provides the data needed to calibrate these parameters correctly.

SORA Nexus Architecture: What Fujiwara Informs

While the complete Nexus guide covers the Iroha 3 architecture in depth, understanding a few key concepts—targeted for Nexus but informed by Fujiwara testing—explains why this testnet matters.

The Iroha Virtual Machine (IVM)

At the core of Nexus is a purpose-built smart contract engine called the Iroha Virtual Machine (IVM). Unlike the Ethereum VM, the IVM is designed from scratch for deterministic, predictable execution. Every validator running the same contract reaches exactly the same conclusion—eliminating the edge cases and quirks that plague other blockchain VMs.

The IVM uses a fixed instruction set, explicit syscalls, and standardized input/output formatting. This means the entire platform becomes far easier to audit and reason about—critical for institutional adoption.

Data Spaces: Sovereignty Within Unity

Data Spaces are SORA Nexus’s solution to the privacy-versus-composability tradeoff. Each data space functions as a sovereign partition with its own governance rules, privacy settings, and participation requirements.

A central bank could run a private CBDC data space with strict access controls, while a DEX operates in a public data space with permissionless participation—both sharing the same network, consensus, and finality guarantees. Assets can move between spaces through governed gateways without requiring risky bridges.

Lanes and the Merge Ledger

Horizontal scalability in Nexus comes from parallel lanes—multiple transaction pipelines processing work simultaneously. Each lane can finalize blocks independently, but a lightweight merge ledger orders lane tips into a single global sequence.

This design delivers throughput multiplication without fragmenting state or sacrificing composability. Under low load, lanes can fuse for efficiency; under high load, they split to maintain performance—all deterministically and without requiring chain forks or manual intervention.

SORA v2 vs. SORA v3: Key Differences

Understanding what’s changing helps explain why Fujiwara represents such a significant milestone.

The transition isn’t abandoning SORA v2—it’s evolving to meet requirements that the original architecture couldn’t address.

How to Participate in Fujiwara

The testnet is live and welcoming community participation. Here’s how to get involved.

Run a Validator Node

Validators help secure the testnet, stress-test consensus mechanisms, and earn experience with the Iroha-based architecture. The official validator guide provides step-by-step instructions.

Running a testnet node requires modest hardware and no financial stake—making it accessible for anyone wanting hands-on experience with SORA Nexus infrastructure.

Monitor Network Activity

The Fujiwara Block Explorer provides real-time visibility into network performance. You can track block times, finality metrics, validator uptime, and transaction throughput.

For developers and researchers, the explorer offers insights into how the Iroha-based architecture behaves under various load conditions.

Join Community Discussions

The SORA community on Telegram actively discusses Fujiwara developments, shares validator experiences, and coordinates testing efforts. This is where you’ll find the latest updates on testnet milestones and upcoming features.

Real-World Context: Why This Matters

Fujiwara isn’t being built in isolation—it’s preparing infrastructure for real-world deployments already in progress.

CBDC Pilots Demonstrating Demand

SORAMITSU, the company behind both Hyperledger Iroha and SORA, has deployed blockchain infrastructure for multiple central banks:

Cambodia’s Bakong has processed transaction volumes exceeding $150 billion annually—demonstrating that blockchain-based infrastructure can operate at national scale. The lessons learned directly informed Nexus design decisions.

The Solomon Islands CBDC pilot (Bokolo Cash) tests how digital currency can serve a geographically dispersed island nation. Papua New Guinea’s Digital Kina proof-of-concept, supported by Soramitsu, evaluated similar use cases for financial inclusion.

Palau Savings Bonds

Perhaps most notably, Palau is implementing blockchain-based savings bonds using SORA and SORAMITSU infrastructure. This represents one of the first sovereign bond issuances on blockchain—exactly the type of institutional use case Nexus is designed to support.

These aren’t theoretical future applications. They’re production deployments testing whether blockchain can meet institutional requirements. Fujiwara validates the next-generation infrastructure these deployments will eventually migrate to.

What Fujiwara Does Not Include

To set accurate expectations, here’s what Fujiwara is NOT testing:

• Final XOR tokenomics: The testnet uses test tokens with no real value. Fee models and economic parameters are being calibrated, not finalized.

• Complete IVM implementation: While the architecture is being validated, the full Kotodama bytecode and smart contract ecosystem is still under development.

• Mainnet migration path: How existing SORA v2 assets and applications will transition to Nexus remains under planning.

• Fixed launch date: SORA’s engineering philosophy prioritizes security, correctness, and efficiency over arbitrary timelines. There is no announced mainnet launch date.

• Production guarantees: Fujiwara is a testnet for validation and learning, not proof of production readiness. Results inform design but do not constitute deployment certification.

The team has consistently emphasized that Nexus will launch “when it’s boring”—meaning when all the exciting problems have been solved and the system is production-ready.

The Name: A Tribute to Resilience

The Fujiwara clan dominated Japanese politics for over 300 years through strategic adaptation rather than military conquest. They navigated shifting power dynamics, built lasting institutional structures, and maintained influence across multiple eras.

This naming choice reflects SORA’s own philosophy: building infrastructure designed to endure and evolve, not chase short-term trends. Just as the Fujiwara clan outlasted multiple ruling families through institutional resilience, SORA Nexus is designed to be the lasting foundation for global economic infrastructure.

Conclusion: Building the Foundation

Fujiwara represents more than a testnet—it’s the proving ground for SORA v3’s Hub Chain and the foundation for SORA Nexus. By validating the Iroha-based hub chain architecture, testing consensus mechanisms with community validators, and calibrating fee models for institutional requirements, Fujiwara is preparing the infrastructure that could eventually host the world’s economic activity on a single, unified ledger.

The transition from SORA v2’s Polkadot-based architecture to SORA v3’s Iroha-powered Hub Chain—and eventually to Nexus on Iroha 3—is significant. It reflects a strategic decision to build infrastructure that can serve central banks and permissionless DeFi on the same network—something no existing blockchain architecture delivers.

For those interested in the complete technical architecture, our SORA Nexus Complete Guide provides comprehensive coverage of IVM, data spaces, lanes, and the governance model. For the latest Nexus announcements, see our coverage of SORA v3 at the Economic Forum.

The Fujiwara testnet is live. The explorer is running. Validators are needed. Whether you’re a developer, researcher, or simply curious about what comes next, there’s never been a better time to get involved in SORA’s evolution.