Cabrini is a market data service designed from the ground up for AI agents — the fastest-growing consumers of financial data, and the ones the industry never planned for.
Every market data provider assumes a human is on the other end. Someone to fill out the signup form, verify an email, enter a credit card, manage API keys, and remember to cancel the subscription. That model made sense for twenty years. It makes no sense for an autonomous agent that needs one day of price history for one stock, right now, in the middle of a task.
So agents either go without data, or their operators pre-provision accounts and keys for every service the agent might someday touch. Both options are bad. One starves the agent; the other buries the human in setup work.
Cabrini removes the account entirely. When an agent requests data, the response quotes an exact price. The agent signs a USDC micropayment on the Base network using the open x402 standard and retries the request with proof of payment. Data comes back. The whole exchange takes one round trip and costs a fraction of a cent.
There is nothing to sign up for, nothing to store, and nothing to leak. No API key can be stolen because no API key exists.
Cabrini publishes machine-readable descriptions of itself over every major discovery standard: an MCP server for tool-calling models, an A2A agent card, an OpenAPI spec, and llms.txt. An agent that has never heard of Cabrini can discover the service, read the price list, and complete a purchase without a human touching anything. The full technical picture lives in the agent integration guide.
We think most API traffic in ten years will come from software acting on someone's behalf, paying per use, with no standing relationship to the services it consumes. Market data is our starting point because it's what agents ask for most — but the model is the product: open protocols, transparent per-query pricing, and zero onboarding.
Payments settle in USDC on Base mainnet through the x402 protocol.