Automatic x402 Payments

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Enable automatic payments

curl --request POST \
  --url https://api.anchorbrowser.io/v1/sessions \
  --header "anchor-api-key: $ANCHOR_API_KEY" \
  --header "content-type: application/json" \
  --data '{"session":{"x402":true}}'

const response = await fetch('https://api.anchorbrowser.io/v1/sessions', {
  method: 'POST',
  headers: {
    'anchor-api-key': process.env.ANCHOR_API_KEY,
    'content-type': 'application/json',
  },
  body: JSON.stringify({ session: { x402: true } }),
});

const { data: session } = await response.json();
console.log(session.cdp_url);

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Payment flow

1. Anchor creates a dedicated AgentCore PaymentSession for the browser session.
2. The browser receives an HTTP 402 Payment Required response from an x402 resource.
3. It selects a payment method compatible with the configured instrument.
4. AgentCore verifies the session budget and generates the cryptographic payment proof.
5. The browser retries the original request once with PAYMENT-SIGNATURE for x402 v2 or X-PAYMENT for x402 v1.
6. The merchant verifies and settles the payment, then returns the protected resource.

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Limits and failure behavior

• Each browser session has a maximum x402 spend of $0.01 USD.
• The payment authorization expires after 480 minutes, even if the browser remains open longer.
• Only document navigation, fetch, and XHR requests are handled automatically.
• If the merchant response is malformed, no compatible network is offered, the budget is exhausted, or AgentCore rejects the payment, the original 402 response is returned to the page.
• x402 controls payments to third-party resources. It does not replace Anchor credits or pay for the browser session itself.

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Security