I built a Stripe-native marketplace where AI agents pay for APIs automatically

A few weeks ago, Stripe shipped their Agent Toolkit — a way for AI agents to hold a payment method and spend money programmatically. I read the announcement and immediately thought: there's nowhere for agents to actually spend this money.

So I built one. This is the story of how, plus the technical decisions and dead ends along the way.

The problem

AI agents increasingly need to call external services — scrape a page, validate a phone number, generate a PDF. Today, that means one of three things for the developer wiring it up:

• Hardcode an API key for every service the agent might need


• Build a custom billing integration per provider


• Maintain a growing pile of subscriptions for services the agent calls a handful of times

None of this is agent-native. An agent that discovers it needs a capability mid-task has no standard way to find a provider and pay for exactly what it uses.

MCP (Model Context Protocol) solves half of this — it standardizes how agents discover and call tools. Stripe Agent Toolkit solves the other half — it lets an agent actually pay for something. Nobody had connected the two into an actual marketplace. That's and the . The and a Python SDK are both on GitHub.

If you maintain an MCP server with something worth monetizing, or you're building an agent that needs to call external services, I'd genuinely like to hear what would make a marketplace like this useful to you.