Machine-payable APIs

Monetize LLM, GPU, and data endpoints per call with sub-millisecond edge cryptography.

XPayr pairs /.well-known/x402.json challenge headers with ES256 JWT access receipts verifiable offline against /.well-known/jwks.json across Cloudflare Workers, FastAPI, Express, and Next.js.

0.5%frais de passerelle forfaitaires
16 Proofsoperational explainers
Pas de gardedirect multisig & vault routing
Réseau de Test (Testnet)avant l'examen du réseau principal
Direct answer

HTTP 402 Paywall Verification lets API providers return a structured 402 Payment Required challenge to unauthenticated clients or autonomous AI agents. Once the non-custodial USDC, USDT, SOL, or NEAR payment confirms, XPayr issues a short-lived ES256-signed JWT that your edge gateway verifies locally using cached public JWKS keys in under 1 millisecond.

01

Client or AI agent calls a protected API endpoint without a valid Bearer receipt and receives HTTP 402 + x402 payment session metadata.

02

Agent or developer completes the 0.5% non-custodial payment (enforced by MCP garde-fous de dépenses déterministes if automated).

03

Client exchanges the confirmed session proof for a signed ES256 JWT scoped to the endpoint quota or TTL.

04

API server or Cloudflare Worker verifies the ES256 signature offline against https://xpayr.com/.well-known/jwks.json.

Who pays gas?

HTTP 402 challenges and ES256 JWT verifications are 100% off-chain; network gas applies only when the on-chain payment settles.

Operational limit

API operators remain responsible for caching JWKS keys, enforcing jti/quota counters at their edge, and setting appropriate token TTLs.

FAQ

What problem does this XPayr flow solve?

HTTP 402 Paywall Verification lets API providers return a structured 402 Payment Required challenge to unauthenticated clients or autonomous AI agents. Once the non-custodial USDC, USDT, SOL, or NEAR payment confirms, XPayr issues a short-lived ES256-signed JWT that your edge gateway verifies locally using cached public JWKS keys in under 1 millisecond.

Who pays gas or network fees?

HTTP 402 challenges and ES256 JWT verifications are 100% off-chain; network gas applies only when the on-chain payment settles.

What should merchants not assume?

API operators remain responsible for caching JWKS keys, enforcing jti/quota counters at their edge, and setting appropriate token TTLs.

Verifiable Open-Source & AI Protocol Registry

Publicly auditable SDKs, cryptographic evidence envelopes, and MCP registries.

Anthropic MCP Registry & NPM

Serveur MCP Officiel à 21 Outils

Registered as io.github.xpayrcom/xpayr-mcp-server on the Official Anthropic MCP Registry and published as @xpayr/mcp-server on NPM and ghcr.io/xpayrcom/xpayr-mcp-server:latest.

Open MCP Portal (mcp.xpayr.com)
Cryptographic Proof & Kit de Licences

Merkle Payment Evidence & ES256 Tokens

Verify on-chain settlement envelopes with @xpayr/payment-evidence and offline-verifiable ES256 wallet licenses with @xpayr/extension-kit.

Open Docs Hub (docs.xpayr.com)
OpenAPI 3.1.0 & Security Policy

30 Open-Source Repositories & RFC 9116

Inspect all 20 REST API v1 schemas interactively at api-docs.xpayr.com, review our 30 repositories at github.com/xpayrcom, and check /.well-known/security.txt & /.well-known/jwks.json.

Open API Playground (api-docs.xpayr.com)

Besoin de prouver le débit avant la production ?

Utilisez la vérification testnet, les documents API, les guides webhook et les explications opérationnelles avant de demander l'activation du réseau principal.