Declan Fox

CPO @Consensys
Builder @LineaBuild

[Declan Fox @DeclanFox14]

ClearToken has done incredible work on the legal and regulatory frameworks for tokenizing digital assets.

And with the technology we’ve built at Consensys, we’re going to help bring those assets to 24/7 markets on scalable and battle tested infrastructure.
More to come! 🤝

[Consensys.eth @Consensys]

Consensys and ClearToken have announced a strategic partnership to bring 24/7 settlement to wholesale markets, pairing cryptographic finality with settlement finality.

Read the full announcement ↓
https://t.co/nVZaZ8Uvc4

[Declan Fox @DeclanFox14]

@category_xyz How does an atomic trade execute between two encrypted domains without one side's validators seeing the other's data?

[Mike Kriak @mkriak]

Back from @Sibos Miami, and what an energizing week.
For years, financial institutions and infrastructure companies like @Consensys (with our teams building @Besu_eth & @LineaBuild rails) have been working together to move tokenization from proof of concept to production. Over the past few months, that shift has accelerated sharply. Seeing it take center stage at the world's largest traditional finance conference, hosted by @swiftcommunity itself, felt like a historic moment. Today, we're truly working hand in hand to build the future of global finance. More to come soon. 🫡

[Consensys.eth @Consensys]

From creating @Besu_eth to maintaining it: at @Consensys, we're proud to have driven its technological development and its adoption across financial institutions.

We're now working on expanding its capabilities.
More to come soon.

[Consensys.eth @Consensys]

We are massively hiring to support our growth across several roles.

If you are interested in joining the team, check out our open positions and apply directly via our careers page.

🔗 https://t.co/mNqldKieiA

[Declan Fox @DeclanFox14]

@davebarna 🤝

[Declan Fox @DeclanFox14]

Consensys has spent the last decade building and maintaining core infrastructure across the Ethereum ecosystem - Besu, Teku, Lineth - and we continue to deliver the L1 strawmap with our L1 guest program (Zesu), lean consensus, and our RISC-V zkVM prover.

More recently, we've been very busy helping to onboard regulated financial institutions to Ethereum (more announcements on this very soon!) using this infra, and now we have a lazer focused organization to execute with.

As we shift towards an ever expanding balance of sovereign people, communities, countries, and networks, nurtured by a matrix of decentralized trust, I'm incredibly excited to be leading our talented product and engineering teams on this journey.

The Summer of Ethereum Love 🫡

[Consensys.eth @Consensys]

Today, Consensys Software Inc. (CSI) is becoming two independent companies.

CSI will continue as the same company and rebrand as MetaMask, operating the MetaMask platform and its consumer-facing products, with Joe Lubin as Chairman and CEO.

CSI’s Protocols Group and institutional blockchain infrastructure business, including Linea and its broader portfolio of enterprise and Ethereum protocol infrastructure, will become a newly formed company, named Consensys, under Mike Kriak (CEO), David Cunningham (President), Declan Fox (CPO), with Joe Lubin as Executive Chairman.

This evolution reflects a turning point in both markets CSI has built over the past decade: consumer self-custody has moved into mainstream financial behavior, while institutional demand has moved from pilots to production. Each now requires its own operating model, dedicated leadership and focused investment strategy to scale.

Learn more: https://t.co/ccGvYHqosN

[Youssef | yelhousni.eth @YoussefElHousn3]

still using pairings? seems gnark-crypto is a a lot faster for BN254 🤔

[Declan Fox @DeclanFox14]

@levantolabs Congrats @bigironchris @marco_derossi 👏

[Levanto Labs @levantolabs]

Meet the first AI to say ''I don't know''.

We think agent mass adoption is blocked by three things: 1) weak security, 2) unreliability, and 3) how hard agents are to set up.

Our first product, Sage, is focused on reliability. It's a "decision model" - a safer, faster, and cheaper way for machines to choose, act, and escalate to a human when confidence is low.

You give it content (up to 32K tokens) and a list of questions (Sort, Yes/No, Choice, Tags, Scale), and Sage answers in 200ms - 9x faster than a traditional LLM - always with a confidence score attached. So yes… it's humble enough to say "I don't know."

You can also turn on "grounding" to automatically run a web search and enrich the context.

Under the hood: we took an open-weights LLM and fused on a classifier through post-training.

It's great for agentic workflows, agentic guardrails, data pipelines, content moderation, operations, and risk & fraud.

Why does this matter? Today's LLMs are great for chatbots, research, and creativity - but automation needs something much faster, with structured outputs, that isn't overconfident and is ready to admit when the signal is too weak.

Sage preview is live. Excited to see your feedback.

Levanto Labs is out of stealth today, founded by @marco_derossi and @bigironchris.

We are hiring, reach out!

Check the links in the post below 😊

[Linea.eth @LineaBuild]

Linea Insights is back 📺

Season 2 opens with @YoussefElHousn3 walking through @gnark_team, our open-source ZK library in Go, and one of the most widely used proving libraries in production.

Episode 1: "What is gnark?"

[Declan Fox @DeclanFox14]

Thanks for hosting a great conversation @DeFi_Dad 🙏🏻

Always a pleasure chatting with @odysseas_eth and the incredible work happening at @phylaxsystems to help protect assets onchain 💪

[DeFi Dad ⟠ defidad.eth @DeFi_Dad]

🎙️ New @Edge_Pod

⚡️ The DeFi Circuit Breaker That Could Have Stopped The rsETH Exploit, And Why Linea Implemented It

0:00 - Intro
2:02 - Declan’s work as Head of Linea
3:15 - What Is Phylax?
4:45 - Ethereum’s security + more controls
12:14 - Protection without sacrificing decentralization
14:33 - What are institutions waiting for?
18:54 - Linea is helping institutions come onchain
23:06 - Freezing assets vs programmatic rules
26:09 - Demand for DeFi transcends politics
32:54 - Circuit breaker for the next rsETH exploit
38:09 - What triggers Phylax to stop an attack?
42:38 - Composable walled gardens on Ethereum
45:56 - Getting started with Phylax
47:32 - Closing

🙏 Thanks to @phylaxsystems Founder & CEO @odysseas_eth and Head of @LineaBuild at @Consensys, @DeclanFox14 for joining us!

[Declan Fox @DeclanFox14]

@ethlabs_org Great mission, great team! 💪

[Linea.eth @LineaBuild]

The next challenge is enabling institutions to settle assets and cash across chains without exposing sensitive data or creating new settlement risk.

Linea and @bermudabayzk show that private, atomic and verifiable settlement is possible.

Blog post ↓
https://t.co/b9y9jHcWjc

[Joseph Lubin @ethereumJoseph]

Another great post from @joechalom and @Sharplink. It is great to see Joseph highlight the remarkable milestone of 1 million lifetime developers that have built or build on Ethereum.

Joseph also touches on some key factors that will lead to the many L2s, and private permissioned Besu Ethereum chains becoming fully composable with each other and L1: credible neutrality, modularity, culture and composability. He sketches the synchronous and near-synchronous composability work that the @Linea team is doing and others including @Zisk and @gnosis_ are doing similar work. Atomic bridgeless execution zones and real-time unification of liquidity fragments will be the benefits and a unified extended Ethereum ecosystem will be the major result. ETH will be resident on all of these networks and used to pay fees for inclusion in multi-network activity to synchronizers who aggregate ZK proofs from the various networks. Ethereum is growing into an increasingly globally systemically important infrastructure, and ETH is about to also become globally systemically important as it will be the fuel and currency that powers transactions, storage, staking and many other functions on the world's main global digital asset processing and settlement layer.

Amusingly, I found this my DevCon5 Osaka keynote entitled "When 1 Million Eth Devs?" We got there. And the keynote does a pretty decent job of sketching how Ethereum will become systemically infrastructure, from way back in 2019.

https://t.co/6mUPS1otzQ

[ETHConf @ethconf]

Governance now matters as much as technology in institutional infrastructure. Open source alone is not enough, and code neutrality is what reduces dependency risk and builds long-term trust.

@DeclanFox14 of @LineaBuild and @rojotek of @Consensys on the Main Stage at ETHConf.

[Joseph Chalom @joechalom]

https://t.co/CEhi4vF5rL

[Linea.eth @LineaBuild]

"The biggest anti-pattern today is the belief that institutions still need their own private, permissioned L1"

@DeclanFox14 at @signalweek on the Institutional Crypto Stack.

ZK proofs changed what's possible. Banks and FMIs can keep their permissioned setup and still connect to Ethereum, without giving up compliance or privacy.

[Aave @aave]

Leading Ethereum stewards @Consensys and @ethereumJoseph have joined DeFi United with up to 30,000 ETH in financial support for the rsETH recovery effort, with ongoing strategic advisory from @Sharplink.

Their contributions are a substantial component of the broader DeFi United effort to restore rsETH's backing and normalize market conditions, and the recovery would not be progressing as it is without them.

DeFi United.

[Thomas Coratger @tcoratger]

Building a zkEVM from scratch is tough, especially when writing raw arithmetization constraints by hand.

At @LineaBuild, the team built ZK Assembly (zkASM), a custom assembly language to make constraint generation faster and easier.

Here is how it works. 🧵👇