@forgemeshlabs/pay-per-crawl-next

Next.js middleware that charges AI crawlers per page with x402 and MPP. Edge-runtime compatible (Web APIs only, DNS-over-HTTPS for search-engine verification). You keep 100%: no account, no custody.

npm install @forgemeshlabs/pay-per-crawl-next

middleware.js (Next 14/15):

import { createPayPerCrawl } from "@forgemeshlabs/pay-per-crawl-next";

const ppc = createPayPerCrawl({ siteName: "My Site" }); // PAY_TO, PRICE_USD, MODE ... come from env; options win
export const middleware = ppc.middleware;

// Next needs `config` as a literal in this file; it cannot be re-exported.
export const config = { matcher: ["/((?!_next/static|_next/image|favicon.ico).*)"] };

Next 16 renamed middleware to proxy.js (Node runtime): export const proxy = ppc.proxy;. Both were built and tested (Next 15.5 edge middleware, Next 16.2 proxy).

Environment (all optional if passed as options): PAY_TO, PRICE_USD (min 0.005), MODE (monitor default, gate to charge), FACILITATOR_URL, CLASS_POLICY, BOT_OVERRIDES, ALLOW_PATHS, TRUST_HEADER, MPP_SECRET, PRO_KEY. Start in monitor.

The middleware also serves /.well-known/x402.json, /llms.txt and /agents.txt. Prefer route handlers? export const { GET } = ppc.handlers.x402Json; in app/.well-known/x402.json/route.js (and llmsTxt, agentsTxt).

Notes

• TRUST_HEADER defaults to x-forwarded-for and the right-most entry is used (what your platform appended). On Vercel the platform sets it. If your server is exposed directly to the internet, set trustHeader: "" so a client cannot forge an IP.
• Replay lock and rDNS cache are per-process memory by default; pass store (any {get, put, delete}) for a shared one across instances. On serverless this is best effort; the on-chain nonce is the hard guard.
• Static assets, /_next/* and non-GET/HEAD requests pass free. Bugs and bad config fail open.
• Example app: examples/next-app, built with next build and run with next start.

How money flows

Crawler signs a USDC authorization; the middleware has the facilitator (PayAI by default) verify and settle, and serves the page only on a settlement transaction hash. USDC lands in PAY_TO.

MIT.