Justin Gainsley | Coinbase - How AI and Blockchain are going to revolutionize payments.

The Host

Jan Philipp Fritsche — Strategic Director at Oak Security, a Web3 cybersecurity firm pioneering research on economic and systemic risks in decentralized systems. Co-Founder of Bermuda.

https://www.linkedin.com/in/janf/

The Guest

Justin Gainsley — Lead of stablecoin payment products at Coinbase, where he has spent four years building the company's payments suite for consumers, SMBs, enterprises, and payment service providers.

https://www.linkedin.com/in/justin-gainsley/

If you offered everyone in the world a dollar account, how many would say yes?

In this episode of MetaMarkets, Jan is joined by Justin Gainsley from Coinbase to separate the stablecoin headline numbers from what is actually happening. The widely cited figure is $40 trillion settled in the last 12 months. Coinbase's own read is closer to $10 trillion of authentic settlement, of which roughly $1 trillion is payments. Two thirds of that is B2B and intra-business flows, around 20% is remittance, and the rest is payouts and payment acceptance.

The more interesting finding sits underneath the volume. Over half of the customers spending stablecoins at checkout hold no other cryptocurrency at all. They are not crypto users. They are people who discovered that a stablecoin is the easiest way to hold the dollar, and started treating it as a financial account. That demand shows up not only in economies with inflation problems but in the EU and the UK too, which reframes the growth story: the limiting factor is not demand for dollars, it is the ability to serve it. What is blocking the rest is crypto complexity, gas fees, wallets, smart contracts, on and off ramps, and the trust gap that enterprise compliance officers still need closed.

On domestic payments, the argument is against cannibalisation and for addition. Every payment arrives with a job to be done: speed, cost, irreversibility, privacy. The rail should then reveal itself. In markets with strong instant rails, stablecoins often lose that comparison, and cross-border remains the killer use case.

Then the conversation turns to the frontier: x402, the "payment required" status code written into the early internet and never built out, now revived so that agents can pay without an API key. Already tens of millions of transactions a month, including sub-cent micropayments, a category that could not exist on legacy rails. Justin splits agentic payments in two. Human-initiated ones still favour cards, because you want the rewards and the chargeback. But for truly autonomous agents, the logic inverts: you cannot KYC an agent, it has no billing address or social security number, and irreversibility stops being a bug and becomes the feature, with no 60-day clawback window. Jan pushes back hard on where that ends, with agents running businesses and paying wages, and says plainly that it feels wrong to him.

The episode closes on the tension the show keeps returning to: privacy versus compliance. Coinbase's answer today is largely custodial, using omnibus accounts and address rotation so that flows are visible but counterparties are not, while the Base team works on zero-knowledge proofs. The honest admission is that transparency is what makes compliance tractable, and that owning the full stack, from know-your-transaction through the travel rule to the wallets, is what lets a chief compliance officer say yes. Add privacy without that stack, and the compliance problem gets much harder.

The takeaway is a reframing. Stablecoins are not winning as a crypto product. They are winning as dollar access for people who never wanted crypto, and the next trillion-dollar payments market may belong to counterparties who are not human at all.