Forerunner Funds a Seventh Agent Payments Protocol

Forerunner led a $30 million Series A into Natural on July 20 to build the transactional plumbing for AI agents, per Tech Startups. Natural enters a field with six competing agent-payment protocols already live. That means builders integrating checkout flows this quarter are picking a side before anyone's declared a winner.

Those six include Google's UCP and OpenAI's ACP, plus Stripe and Tempo's MPP, which lists Visa as a design partner. Google also runs a separate protocol called AP2, and Ant International built AMP for mobile-first agents. Mastercard rounds out the group with Agent Pay for Machines, spanning cards, bank accounts, and stablecoins.

Here's the part that should worry anyone about to pick a side. Adyen didn't wait for the field to narrow.

On June 16, it shipped a three-layer API suite: Agentic Feed, Agentic Cart, and Agentic Payments. It's built to work with Meta's AI checkout, and it supports UCP, ACP, and AP2 at once, per the same roundup.

A payments processor doesn't build a protocol-agnostic layer for fun. It builds one when customers ask which spec to integrate and nobody has a good answer. Adyen's abstraction is a hedge, and it's the clearest signal that the market is pricing in a multi-protocol outcome rather than a winner.

That's the bet I'd make too, and it's the one Natural has to prove wrong to justify a seventh entrant. If I were deciding where to put integration time this quarter, I'd point at the Adyen layer, not any single protocol's spec sheet.

Watch whether Stripe, Mastercard, or Ant ship their own abstraction layers next. That's the tell that processors, not model labs, end up owning the interface agents check out through.