Agents that pay
their own way
A shared corporate card doesn't scale to a thousand autonomous agents. x402 lets each agent settle for exactly what it uses, per request, in stablecoins — over plain HTTP.
Shared cards don't scale to agents
Human billing assumes a human in the loop — a card on file, a monthly invoice, a person to reconcile it. Autonomous agents break every one of those assumptions.
Hand a thousand agents one shared key and you've built a single point of failure with no per-actor accounting. One runaway loop drains the balance for everyone, and the invoice tells you nothing about which agent spent what, or why. You've pooled the risk without pooling any of the visibility.
Provision a card per agent and the overhead swallows the point of automating in the first place — issuing, rotating, and revoking thousands of credentials, each with its own limit to babysit.
Neither approach meters at the grain that matters: the individual request. Agents don't buy monthly seats. They make calls.
Per-request stablecoin micropayments
x402 revives the long-dormant HTTP 402 status code and turns it into a payment handshake. Meter any endpoint; let the agent settle the exact cost of each call itself.
An agent calls a metered endpoint with no payment attached — an ordinary HTTP request to an ordinary URL.
The server replies 402 with a machine-readable quote: scheme, network, the exact amount, the asset, and the address to pay.
The agent signs a stablecoin payment and retries with an X-PAYMENT header. The server verifies, settles, and returns the resource with a receipt.
A quote an agent can read
When a request arrives unpaid, the server answers 402 with a small JSON body describing exactly what it will accept. No SDK lock-in — any client that speaks HTTP can parse it, sign a payment, and retry.
The settlement scheme. exact charges the quoted amount, no more.
The settlement network. Base and Base Sepolia today; more to come.
The price of this request, denominated in the asset below.
A dollar-pegged stablecoin — predictable cost, no volatility.
The address that receives settlement for the request.
The metered endpoint the quote is priced for.
Billing at the grain of a request
The unit of agent work is the call. x402 prices, meters, and settles at that same unit — so cost, attribution, and control all line up.
Per-agent accounting
Every payment carries the agent that made it. Spend is attributable by default — no invoice archaeology.
No shared blast radius
A wallet per agent means a runaway loop spends only its own balance. One agent can't drain the fleet.
Stablecoin settlement
Dollar-pegged USDC keeps cost predictable to the fraction of a cent, with settlement in seconds, not net-30.
Plain HTTP
402, a header, a retry. No proprietary rails to integrate — if it speaks HTTP, it can pay.
Metered by resource
Price each endpoint independently. Cheap reads, richer writes — the price sheet lives next to the routes.
Signed receipts
Each settlement returns a receipt the agent can reconcile, closing the loop between spend and work done.
Let your agents pay their own way.
Meter your first endpoint and watch agents settle usage per request — no shared card, no surprises. Free to start, no credit card required.