How Automated Agents Pay Each Other: x402 Protocol Explained

Description and use

The x402 protocol enables automated agents to pay per request via HTTP 402 and USDC on Base, eliminating manual account and key requirements.

Problem

Automated systems need to transact programmatically, but traditional payment rails require manual intervention—accounts, API keys, subscriptions.

Outcome

The x402 protocol enables fully automated, per-request payments between agents using USDC on Base, removing manual account and key management.

Workflow

• 1. Agent sends request to a paid API endpoint.
• 2. Endpoint responds with HTTP 402 and a payment instruction in the body.
• 3. Agent pays the specified USDC amount on Base to the endpoint’s wallet.
• 4. Upon receipt, the endpoint processes the request and returns the response.
• 5. Agent repeats the cycle for subsequent requests.

Evidence

We built a system where automated agents pay per request using the x402 protocol — HTTP 402 + USDC on Base. No accounts, no keys, just wallets and code.

Source