For API developers
Monetize your API for AI agents
Charge AI agents per API call instead of provisioning keys and plans for callers you’ll never meet. Register a route, add one middleware, and any endpoint returns a signed x402 challenge — agents pay in USDC and the call succeeds.
Traditional API monetisation assumes a human signs up, gets a key, and picks a plan. Autonomous agents don’t fit that flow: they show up once, want one result, and can pay on the spot. Pay-per-call matches how they actually behave.
With Paywall you keep your existing routes; the SDK adds a payment gate in front of the ones you choose. Non-gated routes are untouched, and you set the price per route.
- 01Register a route + price
Define the endpoint and its price in the dashboard; issue a test or live API key.
- 02Add the SDK
One middleware in Express, Next.js, FastAPI, Django, Laravel, Go, Spring Boot, ASP.NET Core, or Rails.
- 03Agents pay per call
Your route returns a signed 402; the agent pays in USDC and retries successfully.
- 04Get paid
Earnings are paid to your wallet automatically, with signed webhooks to reconcile.
- No key/plan provisioning for unknown callers
- Per-route pricing — gate only what you choose
- Test mode to prove it end-to-end before live
- Signed, retried webhooks for reconciliation
FAQ
No. You add one middleware in front of the routes you want to charge for; everything else stays as it is.
Your route returns a signed x402 402 with a USDC price. The agent (or its runtime) pays and retries with proof; the call then succeeds.