Builder's Block #019: Arbitrum's Product Priorities & Meet the Sponsors Backing London Founder House

📣 Announcements

Key updates from the Arbitrum ecosystem and Foundation.

LG Electronics Pilots Onchain Advertising Network on Arbitrum

LG Electronics is piloting an on-chain advertising network on Arbitrum. Developed by the company’s Blockchain Research Lab, the project explores whether advertising performance can be recorded in a transparent, verifiable format that all stakeholders can independently review.
➡️ Read more here

Meet the Sponsors of Open House London

Open House London is made possible by an incredible group of industry-leading teams committed to support the next generation of businesses launch in the programmable economy. Apply now
➡️ Check out the full lineup of sponsors

📚 Learn & Build

New learning drops and hands-on resources from across the Arbitrum ecosystem.

The agent economy has a verification problem

When you call a model API, you trust the provider to run the model they promised, but there's no way to verify it.

This article from our DevRel @hummusonrails breaks down a paper from Offchain on verifiable AI inference, and how it could bring proof generation from minutes to milliseconds.
➡️ Read more here

X402 and Agentic Commerce with Arbitrum & AWS

Join @hummusonrails from Arbitrum Foundation & @maishsk from @awscloud for a live walkthrough and demo of x402 agentic payments built on AWS AgentCore and Arbitrum's settlement layer.

Perfect for devs building agentic applications for the upcoming Arbitrum London Founder House.
➡️ Sign up now

How Founder House Supports Early-Stage Teams

Early stage teams need the right environment to scale their businesses in the programmable economy.

Arbitrum Founder House is coming to London on July 10-12, a 3-day program to help founders refine their product direction & GTM strategies with up to $300k in prizes and grants.

Watch this video to learn what Founder House London is all about 👇🏻

🔦 Ecosystem Highlights

Fresh launches and standout threads from around the Arbitrum ecosystem.

Arbitrum: The Architecture of the Programmable Economy

Global markets still rely on fragmented systems where payments pause at borders and innovation moves slowly. Arbitrum is now evolving from a scaling solution to the finance-native platform powering the programmable economy.

In this article, we explore the architecture being developed to support this future, from predictable costs and protocol-level compliance to configurable privacy and faster settlement.
➡️ Read more here

Mastercard Taps Arbitrum For Global Stablecoin Settlement

Mastercard has announced a major expansion of its global settlement capabilities, choosing Arbitrum as one of the networks to support its new onchain infrastructure.

As payment flows shift toward an internet-native paradigm, Mastercard is making 24/7 financial operations a reality by introducing intraday, weekend, and holiday settlement options.
➡️ Read more here

Arbitrum Ranked in Fortune Crypto 100

Arbitrum has been named to the inaugural @FortuneMagazine Crypto 100, a definitive ranking of the most influential companies in blockchain.

Together with our ecosystem, we're building the finance-native platform powering the programmable economy for builders, enterprises and institutions.
➡️ Read more here

🛠️ Dev Tooling & Infra

Updates to SDKs, CLIs, and developer workflows across the stack.

PayAI - The largest x402 facilitator now supports Arbitrum

PayAI, the largest x402 facilitator on Solana and a top facilitator across the broader x402 ecosystem, expands its multichain support to Arbitrum One, allowing faster settlements, lower fees, & more reach.

Any agent, app, or API integrated with PayAI can now accept and pay for resources on Arbitrum using the same x402 flow.
➡️ Read more here

ArbOS 40 Compatibility Notice: Upgrade to Nitro v3.10 + Consensus v51

We recommend that all chains upgrade to Nitro v3.10+ and its WASM module root to Consensus v51+. These releases include the latest hardening, improvements, and maintains backward compatibility with previous ArbOS releases.
➡️ Read about the upgrade here

Enable Gasless Payments and Wallets for AI Agents with Q402

Q402 is now live on Arbitrum.

Through a single MCP integration, developers can plug it into Claude, Cursor, Cline, Codex, or any MCP client, and the agent gets equipped with gasless payments, recurring payments, & Agentic Wallets out of the box.
➡️ Try it here

🗓️ Events

Workshops, hackathons, and ecosystem meetups to watch.

Founder House London is bringing early-stage teams together with a $300K prize pool

Starting July 10th, teams will join a 3-day, in-person founder program to receive technical, product, and GTM guidance through workshops, showcase their products during demo sessions + compete for prizes, and bring businesses onchain to Arbitrum and the RobinhoodApp Chain.
➡️ Apply here

🧵 Forum & Community Discussions

What builders are debating and proposing this week.

Minimizing Arbitrum Nova

As per a recent proposal, the ArbitrumDAO has voted to minimize Arbitrum Nova by transitioning it into a maintenance-oriented state with reduced capacity and deprioritized support.
➡️ Read the full details

Arbitrum Audit Program: Transparency Report #3

The DAO-approved Arbitrum Audit Program (AAP) completed its third operational quarter during the period from February 01, 2026, to April 30, 2026 (“Q3”). 108 applications received during Q3, with DeFi remaining the most prominent category.

Across 14 completed audits, 297 vulnerabilities were identified (including 8 classified as critical and 31 as high), and 21,882 lines of code were reviewed.
➡️ Read the full details

[Constitutional] AIP: Transition Arbitrum One ordering policy to Priority Gas Auctions (PGA)

This Constitutional AIP proposes to disable Timeboost on Arbitrum One and replace it with a Priority Gas Auction (PGA) mechanism, an ordering policy that’s more familiar for actors who are willing to pay for transaction priority, allowing more market participants to be a part of Arbitrum’s next phase of growth. In addition, it would sunset Timeboost on Arbitrum Nova.
➡️ Read the full details

That’s all from Builder’s Block #019. Thank you for reading, and keep building. Arbitrum Everywhere.