Mints Banking · Payments
The payment is the request.
An agent hits a paid endpoint, receives 402 Payment Required, signs a payment locally, and retries — settled in one round trip. Machine-speed commerce with a signed receipt for every transfer.
HTTP/1.1 402 Payment Required
How x402 works
Payment
Required.
Every paid API endpoint can speak x402. The server names its price. The agent signs and pays in one exchange. No human in the loop, no pre-authorization, no custody handoff.
Payment settles in the retry request — no pre-authorization, no custodian.
A payment protocol that requires a checkout page isn't a payment protocol — it's a suggestion.
The x402 lifecycle
Five steps. One HTTP exchange.
The entire payment — quote, signing, settlement, and receipt — fits inside a single request-retry cycle. No out-of-band flows, no redirects.
Request
Agent calls a paid endpoint. No pre-authorization, no API key in the call.
402 Response
Server returns HTTP 402 with a price quote and payment address in the headers.
Sign locally
Agent signs the payment with its own key on its own device. Key never leaves.
Retry
Agent reattaches the signed payment to the original request and retries.
Settled
Mints verifies, settles, and returns a signed receipt. The resource responds.
Request
Agent calls a paid endpoint. No pre-authorization, no API key in the call.
402 Response
Server returns HTTP 402 with a price quote and payment address in the headers.
Sign locally
Agent signs the payment with its own key on its own device. Key never leaves.
Retry
Agent reattaches the signed payment to the original request and retries.
Settled
Mints verifies, settles, and returns a signed receipt. The resource responds.
What the agent sends and receives
Every payment, fully verifiable.
The agent attaches a signed payment to the retry request using standard HTTP headers. The resource server verifies with Mints and responds immediately — no webhook, no polling.
What the agent sends
What the agent receives
CLI
$ mints pay did:oas:l1fe:agent:9b1d…44f0 12.50
✓ payment settled in 142ms tx_01JXF8KPmq9Rn4Vz…e7aBProperties
What makes x402 different.
The agent pays inside the same HTTP call it was already making. There is no checkout flow because payment is the flow.
Native to HTTP
402 Payment Required is a standard HTTP status code. Any server can issue one. Any HTTP client can respond to one — including agents that have never been patched for payments.
Locally signed
Payment authorization happens on the agent's own device. The key that signs the payment is the same key bound to the agent's DID — Mints verifies the signature but never holds the key.
Receipts as data
Every settlement returns a structured, signed receipt. Store it, prove it, reconcile against it. The receipt is derivable from the immutable event log — it cannot be forged retroactively.
No SDK required
Resource servers verify payments by calling a single Mints endpoint. They don't need to implement signing, key management, or settlement logic — that burden stays with the agent.
Multi-currency
Quotes arrive in the currency the resource server requests. Mints handles the conversion and settles net positions — the agent signs against the quoted amount, not an exchange rate.
Composability
Payments compose with the rest of the stack.
x402 is a primitive. It integrates natively with every other Mints product without extra configuration — the account, escrow, channels, and settlement layer all understand signed payment flows.
Accounts
Every x402 payment debits an agent's self-custody account. Budget controls apply before signing — the key won't authorize a payment that would violate the agent's spending policy.
Escrow
Hold a payment in escrow via x402 with milestone conditions. The resource server requests payment into an escrow address; release happens when conditions are verified.
Channels
For high-frequency endpoints — inference APIs, data feeds, compute — open a payment channel once and stream value per request. Each call is settled off-ledger; the channel closes to net result.
Start accepting and making agent payments.
Mints is in early access. x402 is production-ready for the agents you're building now.