# Cloudless x402 — pay-per-request APIs

> Machine-consumable APIs paid per invocation with x402 — no signup, subscription, or API key. Each successful request settles on-chain and returns payment evidence. First endpoint: the currently supported AWS Lambda runtimes, returned as fresh, structured data.

This is an agent-facing endpoint. Pay for one HTTP invocation and receive the result plus on-chain settlement evidence; the commercial interaction ends there. No account, subscription, or API key.

## Paid routes

- [GET /v1/lambda-runtimes](https://x402.cloudless.sh/v1/lambda-runtimes): Currently supported AWS Lambda runtimes, parsed live from the AWS documentation and returned as structured JSON. Price: $0.001 USD Coin on Base (eip155:8453).

## Discovery (machine-readable)

- [OpenAPI](https://x402.cloudless.sh/openapi.json): routes and payment terms (OpenAPI 3.1 with x-payment-info).
- [x402 well-known](https://x402.cloudless.sh/.well-known/x402): x402 discovery document (version and resource URLs).

## How payment works

GET a paid route and you receive HTTP 402 with an x402 PAYMENT-REQUIRED challenge (network, asset, amount, recipient). Sign an `exact` EVM payment authorization and retry with a PAYMENT-SIGNATURE header; the facilitator settles on-chain (gasless EIP-3009) and the 200 response carries a PAYMENT-RESPONSE reference. If the static terms above are known, a client may send PAYMENT-SIGNATURE on the first request. x402 v2. The runtime 402 is authoritative over this file.

## More

- [x402 specification](https://github.com/x402-foundation/x402/blob/main/specs/x402-specification-v2.md)
- [Listing on x402scan](https://www.x402scan.com/server/e6c329e9-1800-4329-a8b2-ba6ee53f69da)
- Contact: hello@cloudless.sh