Charge AI training crawlers for access (x402 gateway)

.env.example

@@ -37,3 +37,9 @@ VAPID_SUBJECT=mailto:admin@threatcrush.com
 # ─── Self-Hosting ───
 # PORT=3000
 # NODE_ENV=production
+
+# Crawl gateway (@profullstack/x402-gateway): AI training crawlers pay $1/day over
+# x402. A SCOPED CoinPay key (payments:create) and the EVM address that receives
+# the USDC. Unset = crawlers still get 402, nothing sold.
+COINPAY_X402_KEY=
+CRAWL_PAY_TO=

apps/web/package.json

@@ -13,6 +13,7 @@
     "@profullstack/autoblog": "github:profullstack/autoblog#v0.4.0",
     "@profullstack/pluginstore": "^0.1.1",
     "@profullstack/stack": "^0.1.3",
+    "@profullstack/x402-gateway": "^0.1.0",
     "@supabase/supabase-js": "^2.101.1",
     "@threatcrush/scan": "workspace:*",
     "isomorphic-dompurify": "^3.12.0",

apps/web/src/app/robots.txt/route.ts

@@ -0,0 +1,9 @@
+import { robotsRoute } from "@profullstack/x402-gateway/next";
+import { gateway } from "@/lib/crawl-gateway";
+
+// Generated from the same crawler lists the gateway enforces: training
+// crawlers are refused everywhere but /crawl (where they can buy a pass),
+// retrieval crawlers are named as welcome, everyone else gets the rules below.
+export const GET = robotsRoute(gateway, {
+  disallow: ["/api/"],
+});

apps/web/src/lib/crawl-gateway.ts

@@ -0,0 +1,27 @@
+import { createGateway } from "@profullstack/x402-gateway";
+import { x402Proxy } from "@profullstack/x402-gateway/next";
+
+/**
+ * Sells crawl access to AI training crawlers (GPTBot, ClaudeBot, CCBot,
+ * meta-externalagent, Bytespider, Applebot-Extended, ...) by the day over
+ * x402, settled by CoinPay in USDC. People, Googlebot and the retrieval
+ * crawlers behind AI search pass through untouched.
+ *
+ * Runs inside the middleware, so nothing here may import Node-only modules.
+ * The env is read through a non-literal key on purpose: Next inlines
+ * `process.env.NAME` at build time, and these are runtime secrets. Without
+ * COINPAY_X402_KEY and CRAWL_PAY_TO the gateway still answers training
+ * crawlers with 402, just with an empty offer.
+ */
+const env = (name: string) => process.env[name];
+
+export const gateway = createGateway({
+  siteUrl: env("SITE_URL") || env("NEXT_PUBLIC_SITE_URL") || "https://threatcrush.com",
+  siteName: "ThreatCrush",
+  coinpay: { apiKey: env("COINPAY_X402_KEY") },
+  payTo: env("CRAWL_PAY_TO"),
+  contact: "mailto:support@threatcrush.com",
+});
+
+/** Resolves to a Response for a refused crawler, or undefined to carry on. */
+export const gate = x402Proxy(gateway);

apps/web/src/middleware.ts

@@ -1,3 +1,4 @@
+import { gate } from "@/lib/crawl-gateway";
 import { NextResponse } from "next/server";
 import type { NextRequest } from "next/server";
 
@@ -83,7 +84,13 @@ function rateLimit(req: NextRequest): NextResponse | undefined {
   return undefined;
 }
 
-export function middleware(req: NextRequest): NextResponse | undefined {
+export async function middleware(req: NextRequest): Promise<Response | NextResponse | undefined> {
+  // Crawl gateway first: AI training crawlers get 402 Payment Required (or the
+  // sales page at /crawl) unless they present a paid pass. People, Googlebot
+  // and retrieval crawlers fall through to everything below.
+  const answer = await gate(req);
+  if (answer) return answer;
+
   if (req.headers.get("next-action")) {
     return new NextResponse(null, { status: 410 });
   }