Rayls x Núclea AMA recap: how Brazil's bank-owned FMI tokenised nearly R$1 billion on Rayls
Núclea, one of Brazil's largest financial market infrastructures, has been tokenising receivables on a Rayls Private Network in production since June 2024, and has now tokenised close to R$1 billion. In yesterday's Rayls x Núclea AMA, Leandro Pereira, Head of Digital Assets at Núclea, joined Marcos Viriato, CEO and co-founder of Parfin, the main developer of Rayls, to explain how Núclea fitted blockchain into its existing systems, and what comes next.
Who is Núclea, and who spoke at the AMA?
Núclea is one of Brazil's largest financial market infrastructures (FMIs). It is owned by 48 major banks and processes around US$5 trillion a year across more than 300 billion transactions, including boletos and TED transfers.
The session was part of a series of AMAs in which Rayls clients share their real onchain activity with the community. As in our first Rayls AMA, the format was an open conversation, with Marcos asking the questions and Leandro answering on behalf of Núclea.
Why did Núclea start tokenising assets?
Leandro explained that Núclea started exploring digital assets and tokenisation more than two years ago, and chose Rayls for the infrastructure. As he put it:
"We bought a roadmap. We actually bought the idea of what you were starting to build. And the main thing, I think, we bought the team."
The goal was never to replace the infrastructure that Brazilian banks already rely on, but to build alongside it. He described the strategy in three layers:
- Complement the legacy systems. New blockchain infrastructure runs alongside the systems Núclea has operated for years.
- Expand with new services. Add new products on top and reduce operating costs.
- Bring traditional finance into the new ecosystem. Use that base to bring banks and other institutions onchain.
The starting asset was receivables, the payment rights that make up much of Brazil's credit market. For the wider context, see our explainer on how real-world asset tokenisation is shaping global finance.
How did Núclea connect Rayls to mission-critical systems?
This is where an FMI differs from a pilot project. Núclea's tokenisation runs on a Rayls Private Network. To connect the new blockchain nodes to systems that have run for years, the team designed a middleware layer, which they called a "translate orchestrator". It sits between the legacy platforms and the network.
Live since June 2024
The system went live in June 2024. In the 18 months since, Núclea has tokenised nearly R$1 billion in assets. Read the full Núclea case study.
From digital twins to native assets
Leandro said the next step is "native" tokenised assets. In this model an asset is registered directly onchain, instead of the token acting as a digital twin of a record held in a legacy database. Because a register is already a database, he sees moving it onchain as an obvious upgrade:
"It's pretty much a no-brainer to think: why should we use this 1970 Chevy V8 instead of using a faster electric car?"
Marcos agreed:
"This is one of the biggest transformations in the financial system, when assets are born in the tokenised format. They are native."
How do performance and privacy hold up at FMI scale?
Leandro said the network has reached a peak of around 12,000 transactions per second, and that the cost of running the private network has fallen sharply since its first version. Marcos put that progress down to building alongside a client in production:
"When products are designed along with a client that's using it in production, the product evolves a lot."
For confidentiality, Núclea was one of the first to run Rayls Enygma, our privacy protocol for shielded transactions, in production. Marcos said the longer-term ambition is to make privacy clients light enough to run on mobile devices.
What comes next for Núclea and Rayls?
Private data, public liquidity
Núclea plans to use the upcoming Rayls Public Chain, currently on testnet, for liquidity and distribution, while sensitive information stays in private environments behind privacy layers. That is the private-to-public model Rayls is built around.
"I think the public Rayls will be really good for us, because we'll be able to really explore the use of a public blockchain using the proper privacy layers, the proper KYC and controls."
A three-layer stablecoin project
Leandro outlined a stablecoin project with three layers:
- Payment layer: onramps and offramps.
- Clearing layer: conversion between the stablecoins issued by different banks.
- Custody and liquidity layer: custody and liquidity provision.
Blockchain as standard as cloud
The speakers' goal is for public blockchain use in 2026 to become as standard and as trusted as cloud computing is today.
What did the community ask?
- Regulation: The speakers expect clearer rules to speed up adoption, naming the CLARITY Act in the US, MiCA in Europe and Brazil's existing framework.
- What changes for investors: Tokenisation could change how assets are serviced, for example moving tokenised stocks between brokers without paperwork.
What does the Núclea AMA mean for Rayls?
- Production, not a pilot. A bank-owned FMI has run tokenisation on Rayls in production since June 2024, connected to mission-critical legacy systems.
- The hybrid model in practice. Private networks handle confidentiality and compliance. The Public Chain will handle liquidity and distribution.
- Settlement is next. Núclea's stablecoin plans point to programmable settlement as the next layer of Brazil's tokenised market, building on the work Rayls did in Brazil's central bank Drex pilot.
Talk to the institutional team
Núclea's journey shows how an FMI can bring its existing operations onchain without replacing them. If your institution is exploring tokenisation, private settlement or access to public-chain liquidity, talk to the institutional team.
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