Monetize Gateway (Pay-per-call)

What it is

The Monetize Gateway lets you charge AI agents for every API call — without writing any payment code. You configure your endpoints and pricing on the Monetize platform, and FluxA inserts a payment proxy in front of your API. When an agent calls your endpoint, the proxy handles x402 payment negotiation automatically; your backend only receives requests that have already been paid for.

How it works

AI Agent                  Monetize Proxy                Your API
   |                           |                           |
   |-- GET /endpoint --------->|                           |
   |<-- 402 Payment Required --|                           |
   |                           |                           |
   |-- sign payment (FluxA) -->|                           |
   |-- GET /endpoint + X-Pay ->|-- forward request ------->|
   |                           |<-- API response ----------|
   |<-- API response ----------|                           |

1. The agent calls your public endpoint on the Monetize proxy.
2. The proxy returns HTTP 402 with the price and payment details.
3. The agent signs the payment via FluxA Wallet (using an x402 mandate).
4. The agent retries the request with the X-Payment header.
5. The proxy verifies payment, forwards the request to your private API, and returns the response.

Your backend sees a normal HTTP request — no payment logic needed.

Supported features

Feature	Details
Pricing	Fixed amount per call, minimum $0.01
Endpoint-level pricing	Different price for each endpoint
Static parameters	Inject private headers / query params (e.g. API keys) — never exposed to buyers
Public / private paths	Buyers see the public path; proxy maps it to your private path

Quick setup

Setting up takes about 5 minutes on the Monetize platform:

1. Add your API server — enter the base URL of your API.
2. Configure server details — name and description for your service.
3. Configure endpoints — map public paths to private paths, set pricing for each endpoint.
4. Review — verify your integration details and share with buyers.

For the full step-by-step walkthrough with screenshots, see Monetize APIs →.

Limitations

• Fixed pricing only — every call to the same endpoint costs the same amount. Dynamic or usage-based pricing is not supported.
• Stateless — no order or session concept; each call is independent.
• No agent-to-agent support — the gateway only handles direct agent-to-API payments.
• No custom payment flow — you cannot add pre-payment validation or post-payment webhooks.

If you need dynamic pricing, order management, or agent-to-agent payments, use Payment Link Checkout instead.

Next steps

• Monetize APIs — full configuration guide with screenshots
• How Buyers Use APIs — what the agent / buyer experience looks like
• Payment Link Checkout — flexible alternative for complex payment flows