ExaAI Labs, the builder behind Exa, has added a way for AI agents to pay for search queries with USDC on Base, without opening an account or creating an API key. Usually, an API customer adds a card, buys credits and generates a key before software can make a request. Here, Exa sends back an HTTP 402 payment request: a machine-readable bill. The agent pays from its wallet, one query at a time, and gets the result after the on-chain payment settles.
Base says more than 96,000 agent transactions have settled this way, with over 700 agents and wallets using Exa. A standard search costs 0.7 of a cent in USDC. The novelty isn’t just accepting stablecoins. Payment replaces account setup and prepaid billing, letting software buy a service at the moment it needs it. That makes USDC programmable metering for machine-to-machine commerce: one request, one payment, one result.
For developers, that offers an additional path alongside conventional API billing; for agents, it removes the need to maintain service-specific accounts and keys. Exa engineer Jakub Hojsan described the model as funding a wallet to access services as needed. That’s an early sign of how wallet-based, pay-per-request billing could work for machine-driven software use.