feat(x402): full browser wallet paywall via @x402/paywall

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@missionsquad/agentindex-api",
-  "version": "1.5.4",
+  "version": "1.5.5",
   "description": "AgentIndex blockchain scanner API",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
@@ -27,7 +27,8 @@
   },
   "dependencies": {
     "@helia/verified-fetch": "^7.0.0",
-    "@missionsquad/x402-proxy": "^0.1.0",
+    "@missionsquad/x402-proxy": "^0.1.1",
+    "@x402/paywall": "2.4.0",
     "cors": "^2.8.5",
     "dotenv": "^16.4.7",
     "evmdecoder": "^0.0.71",

src/index.ts

@@ -1,6 +1,7 @@
 import express from 'express'
 import cors from 'cors'
 import { createX402ProxySdk } from '@missionsquad/x402-proxy'
+import { createPaywall, evmPaywall } from '@x402/paywall'
 import { WebSocketServer, WebSocket } from 'ws'
 import { env } from './env'
 import { log } from './utils/logger'
@@ -141,6 +142,12 @@ if (x402App) {
     },
     syncFacilitatorOnStart: env.X402_SYNC_FACILITATOR_ON_START,
     endpoints: buildSearchX402Endpoints(env.X402_UPSTREAM_ORIGIN),
+    // Full wallet-connect payment UI for browsers hitting protected endpoints
+    // (connect wallet, pay in USDC, auto-retry with the payment header). Without
+    // a provider, @x402/core serves its bare "Payment Required" fallback page.
+    // testnet mode is derived from defaultNetwork by x402-proxy.
+    paywall: createPaywall().withNetwork(evmPaywall).build(),
+    paywallConfig: { appName: 'AgentIndex' },
   })
 
   x402.install(x402App)

src/types/x402-paywall.d.ts

@@ -0,0 +1,38 @@
+/**
+ * Minimal ambient types for @x402/paywall (pinned to 2.4.0).
+ *
+ * The package publishes its type declarations only through the package.json
+ * `exports` map, which this project's `moduleResolution: "node"` cannot read.
+ * Node itself resolves the runtime require() through `exports` without issue,
+ * so only the compiler needs this shim. Keep in sync with the pinned version's
+ * public API (createPaywall builder + network handlers).
+ */
+declare module '@x402/paywall' {
+  /** Network-specific paywall handler (opaque — pass to withNetwork). */
+  export interface PaywallNetworkHandler {
+    [key: string]: unknown
+  }
+
+  export interface PaywallConfig {
+    appName?: string
+    appLogo?: string
+    currentUrl?: string
+    testnet?: boolean
+  }
+
+  /** Matches @x402/core's PaywallProvider structurally. */
+  export interface PaywallProvider {
+    generateHtml(paymentRequired: unknown, config?: unknown): string
+  }
+
+  export class PaywallBuilder {
+    withNetwork(handler: PaywallNetworkHandler): this
+    withConfig(config: PaywallConfig): this
+    build(): PaywallProvider
+  }
+
+  export function createPaywall(): PaywallBuilder
+
+  export const evmPaywall: PaywallNetworkHandler
+  export const svmPaywall: PaywallNetworkHandler
+}