The online buildathon phase opens May 25, 2026, with an in-person Founder House running June 25 to 28 in London. Submissions close June 10, with rewards distributed June 17 through the HackQuest platform. London is the second stop in a four-city global program carrying a combined $800,000 prize pool. The first stop, New York City, awarded $340,000 to 177 projects built by more than 1,700 participants.

The London program is structured around three tracks. The Open Category accepts general applications. The AI Agentic Category targets projects integrating autonomous agents with on-chain infrastructure. The third track is exclusive to Robinhood Chain, an Arbitrum Orbit Layer 2, and offers both a Founder-in-Residence award and an Innovation Award. Robinhood Chain recorded 4 million testnet transactions shortly after launch and has committed to a developer ecosystem fund exceeding $1 million. The prize split is $115,000 for the online buildathon phase and $300,000 for the Founder House phase.

The Foundation has signaled that it wants London builders focused on payment rails, agentic commerce, prediction markets, and tokenized assets. Those themes connect directly to two infrastructure developments announced in recent weeks.

Wallet Standards Catch Up to Agent Use Cases

MetaMask activated ERC-7715 on Arbitrum through its Smart Accounts Kit on April 6. The standard is formally titled "Request Permissions from Wallets" and is implemented in MetaMask's product under the name Advanced Permissions. It introduces a method that lets a decentralized application ask a user's wallet once for a defined, time-limited set of permissions, then act within those bounds without requiring the user to sign each transaction individually. Permitted operations can include token transfers, gas limits, and call rate limits, all tied to a mandatory expiry. The standard was first proposed in May 2024 and was led by Pedro Gomes of WalletConnect/Reown and co-authored by contributors from MetaMask, ZeroDev, Biconomy, and Alchemy.

Ayush Bherwani, Senior Developer Relations Manager at MetaMask, described the practical effect: "Grant dapps scoped, time-bound access to execute on behalf of users without extra signatures, separate wallets, or custody tradeoffs."

A separate but related initiative, the Open Wallet Standard (OWS), was launched on March 23 by MoonPay and open-sourced under an MIT license. OWS provides the infrastructure layer that lets AI agents hold and transact funds without ever accessing a private key directly. It uses AES-256-GCM encryption at rest and an internal policy engine that evaluates each transaction before execution. Arbitrum is listed among more than 15 contributing organizations, alongside PayPal, Circle, the Ethereum Foundation, and others. The standard supports eight chain families, including EVM networks, Solana, Bitcoin, and Cosmos. That multi-chain reach is particularly relevant in markets such as sub-Saharan Africa, where users often hold assets across several fragmented networks.

MoonPay CEO Ivan Soto-Wright framed the release plainly: "The agent economy has payment rails. It didn't have a wallet standard. We built one, open-sourced it, and now the full stack exists."

Mentorship Program Draws 900 Applications for Roughly 15 Seats

The Arbitrum Mentorship Program closed applications on April 7 with 900 submissions. The program offers approximately 15 seats, putting the implied acceptance rate at roughly 1.7 percent. It is structured as an eight-week, equity-free accelerator for teams at the MVP to pre-seed stage. Mentor and investor partners include Pantera Capital, Electric Capital, Lightspeed, IOSG, and Tandem, alongside ecosystem teams from GMX, Pendle, Fhenix, and Robinhood Chain. The top three teams at the program's Demo Day will receive $100,000 in non-dilutive awards.

Regional Access and On-Chain Context

The buildathon's online phase is open to global participants. Builders in Lagos, Nairobi, Mumbai, Bengaluru, or Karachi can compete for the $115,000 prize pool without traveling to London. Only the Founder House requires in-person attendance. This matters in markets where Arbitrum already has documented traction: the Foundation ran a prior Open House in Bengaluru that drew 500 applications, and Nigeria was one of three launch markets for the Arbitrum Ambassador Program in 2024, alongside India and Mexico. A Kenyan project called NexusPay has been building a stablecoin payment wallet on Arbitrum One with integration into mobile money infrastructure. NexusPay is developed by the co-founders of Burstek DAO, which has submitted a proposal to the Arbitrum DAO for a grant of approximately 1.4 million ARB to support expansion across East Africa.

The payment rails and agentic commerce tracks have particular relevance in African and South Asian markets, where cross-border remittances and mobile-first DeFi access remain active areas of development. ERC-7715's ability to reduce repeated signing is also practical in high-frequency use cases common on smartphones.

On the network side, Arbitrum One holds roughly $2.8 billion in DeFi total value locked, representing about 31 percent of all L2 DeFi TVL, and approximately $15.2 billion in total value secured across bridges. ARB is trading near $0.11, up about 20 percent over the past seven days, with a market cap around $678 million. A token unlock of 92.65 million ARB is scheduled for April 16, 2026.

Registration for Open House London is live at arbitrum-london.hackquest.io.