Builder's Block #023: $415k in Prizes at Open House Singapore - Apply Now
🇸🇬 Open House is Coming to Singapore with $415k in Prizes & Grants
⚙️ ArbOS 61 Elara: Contract Size Limits + Compliance Controls
⚠️ $1M+ Raised by Teams from the Arbitrum Mentorship Program
📣 Announcements
Key updates from the Arbitrum ecosystem and Foundation.
Open House Singapore: 3-Week Buildathon Applications Now Open

Our global founder program, Open House Singapore, is kicking off its first phase with a 3-week online Buildathon starting September 14th, designed to help early-stage teams go from idea to product.
During this phase, teams get technical and infra support from ecosystem partners, win $115K prizes, and earn a spot at our in-person Founder House in Singapore
ZK on Arbitrum: A Faster Path Without Removing Optimistic Settlement

Offchain's research team is exploring how ZK proofs could be integrated into Arbitrum’s settlement process, with the goal of enabling faster transaction finality while preserving the security guarantees and fallback mechanisms of optimistic rollups.
The tweet outlines a potential path toward ZK settlement for Arbitrum One and chains built on the Arbitrum platform.
ArbOS Elara Brings 96kb Smart Contracts & Protocol-Level Compliance

ArbOS Elara introduces more programmable parameters including protocol-level compliance controls for dedicated blockchains, alongside improvements to fees, data availability, and Stylus capacity.
This upgrade has been approved by the ArbitrumDAO for Arbitrum One and Arbitrum Nova, where it activates on Thursday, August 20, 2026, at 17:00 UTC.
Arbitrum Mentorship Program Winners Announced

Earlier this year, the Arbitrum Foundation ran the first full cohort of the Arbitrum Mentorship Program. Ten teams made it through to Demo Day. Between them, they raised more than $1M over the course of the program, shipped on Arbitrum One and Robinhood Chain, and four walked away with a share of the $100,000 prize pool.
📚 Learn & Build
New learning drops and hands-on resources from across the Arbitrum ecosystem.
How the New ArbOS Update Will Change the Way We build on Arbitrum

ArbOS 61 Elara brings a major upgrade for Stylus developers: a 4× increase in the code size limit (24 KB → 96 KB), a larger WASM size ceiling, and changes to WASM multi-value support that could affect existing contracts. This article breaks down what you need to know before the upgrade goes live.
What Would Change If Arbitrum Replaced Its State Tree

Offchain published an RFC on the Arbitrum forum a few weeks ago asking the community what would change for you if Arbitrum replaced that structure. The work is in the research phase now, but before you can even contribute you need to understand what's at stake.
How Do You Prove You Know A Secret Without Revealing It Onchain? - A Beginners Guide

How do you prove you know a secret without revealing it onchain? zkSNARKs make it possible. From commitments and witnesses to polynomial checks and onchain verification, this beginner’s guide walks through the full lifecycle of a zero-knowledge proof with practical examples.
ZeroDev Guide: Design Cross-Chain Wallet Funding Without Manual Bridging

An empty wallet isn’t a successful onboarding flow.
The real test comes when users fund their account and can immediately do what they came to do. Cross-chain funding should start with user intent, not bridges, gas, or network selection.
Where Offchain Is Pushing Zero-Knowledge Forward

From faster data verification and verifiable AI to confidential payments and stronger recursive proofs, Offchain is expanding what zero-knowledge technology can do while strengthening the foundations beneath it.
🔦 Ecosystem Highlights
Fresh launches and standout threads from around the Arbitrum ecosystem.
Stripe Now Supports USDC on Arbitrum

Stablecoin accounts are becoming part of global finance. Supported in 100+ countries, Stripe Treasury gives eligible businesses a full financial account to receive, hold, and send USDC on Arbitrum.
Total RWA Value on Arbitrum Hits $900 million

Total Tokenized Value on the Robinhood Chain reached a new high of $29M. Finance is becoming programmable with Arbitrum under the hood.
🛠️ Dev Tooling & Infra
Updates to SDKs, CLIs, and developer workflows across the stack.
ArbOS Elara: What It Enables for Arbitrum One & Dedicated Blockchains

ArbOS Elara has been approved by the ArbitrumDAO.Once live, the upgrade will provide chain operators with more programmable controls over compliance, fees, and data infrastructure, while expanding capacity on Arbitrum One.
🗓️ Events
Workshops, hackathons, and ecosystem meetups to watch.
Open House Singapore online Buildathon kicks off September 14

Open House Singapore will kick off with a 3-week, online Buildathon on September 14, designed to help founders refine their direction and iterate towards an MVP. Teams that are looking to bring novel financial products to the Arbitrum Platform are welcome to apply today.
đź§µ Forum & Community Discussions
What builders are debating and proposing this week.
[RFC] New state representation for Arbitrum: proof-format change and request for feedback
Offchain is researching replacing the current Merkle-Patricia Trie with a new verifiable data structure.
This change aims to scale Arbitrum chains to new heights that optimizing the MPT cannot alone achieve, continuing the work to improve Arbitrum chains over time.
Post-Quantum Cryptography Risk in Arbitrum Smart Contracts — A Technical Overview
Quantum computing could eventually break the cryptography securing today’s smart contracts.
This technical overview looks at where Arbitrum contracts may face post-quantum risk - from ecrecover and EIP-712 to Chainlink feeds, Safe, and permit() - and what migration paths already exist.
That’s all from Builder’s Block #023. Thank you for reading, and keep building. Arbitrum Everywhere.