AI agents can now access 0x Protocol's Swap API by paying $0.01 per request in USDC from their own wallets, with no API key or account setup required. The integration, built with Alchemy AgentPay, runs on the HTTP 402 standard and extends the protocol's DeFi liquidity aggregation to autonomous software agents for the first time.
The mechanism follows the x402 protocol flow: an agent sends an HTTP request to the 0x endpoint, the server returns a 402 Payment Required response, the agent signs a USDC payment on-chain, and a proxy verifies the transaction before releasing swap data. Payment is accepted via x402 on Base and Solana, or via the Machine Payment Protocol (MPP), per the 0x thread on X Tuesday.
Traditional API access requires an account, a credit card, a key, and a billing cycle. None of those map cleanly to an autonomous process that may need to execute a single swap query before spinning down. The pay-per-request model lets an agent call the endpoint when it needs it and pay only for what it consumes, at $0.01 per call.
0x's Swap API aggregates liquidity across major DEX venues, making it one of the more practical data sources for any agent that needs onchain pricing or routing. Opening it to API-keyless access removes the setup step that would otherwise require human intervention before an agent can run.
