Add MPP to API submodule

app/api/chat/route.ts

@@ -2,6 +2,7 @@ import type { NextRequest } from "next/server";
 import { NextResponse } from "next/server";
 import { getCorsHeaders } from "@/lib/networking/getCorsHeaders";
 import { handleChatStream } from "@/lib/chat/handleChatStream";
+import { withMPP } from "@/lib/mpp/withMPP"
 
 /**
  * OPTIONS handler for CORS preflight requests.
@@ -36,6 +37,8 @@ export async function OPTIONS() {
  * @param request - The request object
  * @returns A streaming response or error
  */
-export async function POST(request: NextRequest): Promise<Response> {
+async function handler(request: NextRequest): Promise<Response> {
   return handleChatStream(request);
 }
+
+export const POST = withMPP(handler);

app/api/content/create/route.ts

@@ -1,6 +1,7 @@
 import { NextRequest, NextResponse } from "next/server";
 import { getCorsHeaders } from "@/lib/networking/getCorsHeaders";
 import { createContentHandler } from "@/lib/content/createContentHandler";
+import { withMPP } from "@/lib/mpp/withMPP";
 
 /**
  * OPTIONS handler for CORS preflight requests.
@@ -22,10 +23,12 @@ export async function OPTIONS() {
  * @param request - Incoming API request.
  * @returns Trigger response for the created task run.
  */
-export async function POST(request: NextRequest): Promise<NextResponse> {
+async function handler(request: NextRequest): Promise<NextResponse> {
   return createContentHandler(request);
 }
 
+export const POST = withMPP(handler);
+
 export const dynamic = "force-dynamic";
 export const fetchCache = "force-no-store";
 export const revalidate = 0;

app/api/image/generate/route.ts

@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from "next/server";
 import { getCorsHeaders } from "@/lib/networking/getCorsHeaders";
 import { x402GenerateImage } from "@/lib/x402/recoup/x402GenerateImage";
 import { validateGenerateImageQuery } from "@/lib/image/validateGenerateImageQuery";
+import { withMPP } from "@/lib/mpp/withMPP"
 
 /**
  * OPTIONS handler for CORS preflight requests.
@@ -22,7 +23,7 @@ export async function OPTIONS() {
  * @param request - The request object containing query parameters.
  * @returns {Promise<NextResponse>} JSON response matching the Recoup API format.
  */
-export async function GET(request: NextRequest) {
+async function handler(request: NextRequest) {
   try {
     const validatedQuery = validateGenerateImageQuery(request);
     if (validatedQuery instanceof NextResponse) {
@@ -54,3 +55,5 @@ export async function GET(request: NextRequest) {
     );
   }
 }
+
+export const GET = withMPP(handler);

app/api/x402/image/generate/route.ts

@@ -4,6 +4,7 @@ import { getCorsHeaders } from "@/lib/networking/getCorsHeaders";
 import { uploadImageAndCreateMoment } from "@/lib/arweave/uploadImageAndCreateMoment";
 import { getBuyerAccount } from "@/lib/x402/getBuyerAccount";
 import { parseFilesFromQuery } from "@/lib/files/parseFilesFromQuery";
+import { withMPP } from "@/lib/mpp/withMPP"
 
 /**
  * OPTIONS handler for CORS preflight requests.
@@ -23,7 +24,7 @@ export async function OPTIONS() {
  * @param request - The request object containing query parameters.
  * @returns {Promise<NextResponse>} JSON response with generated image URL or error.
  */
-export async function GET(request: NextRequest) {
+async function handler(request: NextRequest) {
   try {
     const { searchParams } = new URL(request.url);
     const prompt = searchParams.get("prompt");
@@ -110,3 +111,5 @@ export async function GET(request: NextRequest) {
     );
   }
 }
+
+export const GET = withMPP(handler);

lib/mpp/pricing.ts

@@ -0,0 +1,7 @@
+export function getPriceForRoute(path: string): number {
+  if (path.includes("/ai")) return 0.002
+  if (path.includes("/data")) return 0.001
+  if (path.includes("/trade")) return 0.01
+
+  return 0.0005
+}

lib/mpp/providers/index.ts

@@ -0,0 +1,5 @@
+import { verifyStripePayment } from "./stripe"
+
+export async function verifyPayment(payment: string) {
+  return verifyStripePayment(payment)
+}

lib/mpp/providers/stripe.ts

@@ -0,0 +1,14 @@
+import Stripe from "stripe"
+
+const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!, {
+  apiVersion: "2024-06-20"
+})
+
+export async function verifyStripePayment(paymentId: string) {
+  try {
+    const payment = await stripe.paymentIntents.retrieve(paymentId)
+    return payment.status === "succeeded"
+  } catch {
+    return false
+  }
+}

lib/mpp/replay.ts

@@ -0,0 +1,7 @@
+const used = new Set<string>()
+
+export function isReplay(id: string) {
+  if (used.has(id)) return true
+  used.add(id)
+  return false
+}

lib/mpp/session.ts

@@ -0,0 +1,44 @@
+import crypto from "crypto"
+
+type Session = {
+  id: string
+  budget: number
+  spent: number
+  expiresAt: number
+}
+
+const sessions = new Map<string, Session>()
+
+export function createSession(budget = 1.0): Session {
+  const session = {
+    id: crypto.randomUUID(),
+    budget,
+    spent: 0,
+    expiresAt: Date.now() + 10 * 60 * 1000
+  }
+
+  sessions.set(session.id, session)
+  return session
+}
+
+export function getSession(id: string): Session | null {
+  const s = sessions.get(id)
+  if (!s) return null
+
+  if (Date.now() > s.expiresAt) {
+    sessions.delete(id)
+    return null
+  }
+
+  return s
+}
+
+export function chargeSession(id: string, amount: number): boolean {
+  const s = getSession(id)
+  if (!s) return false
+
+  if (s.spent + amount > s.budget) return false
+
+  s.spent += amount
+  return true
+}

lib/mpp/withMPP.ts

@@ -0,0 +1,56 @@
+import { getPriceForRoute } from "./pricing"
+import { verifyPayment } from "./providers"
+import { createSession, getSession, chargeSession } from "./session"
+import { isReplay } from "./replay"
+
+export function withMPP(handler: Function) {
+  return async (req: Request, context?: any) => {
+    const path = new URL(req.url).pathname
+    const price = getPriceForRoute(path)
+
+    const payment = req.headers.get("x-mpp-payment")
+    const sessionId = req.headers.get("x-mpp-session")
+
+    if (sessionId) {
+      const session = getSession(sessionId)
+
+      if (!session) {
+        return Response.json({ error: "invalid_session" }, { status: 402 })
+      }
+
+      if (!chargeSession(sessionId, price)) {
+        return Response.json(
+          { error: "insufficient_balance", required: price },
+          { status: 402 }
+        )
+      }
+
+      return handler(req, context)
+    }
+
+    if (payment) {
+      if (isReplay(payment)) {
+        return Response.json({ error: "replayed_payment" }, { status: 402 })
+      }
+
+      const valid = await verifyPayment(payment)
+
+      if (!valid) {
+        return Response.json({ error: "invalid_payment" }, { status: 402 })
+      }
+
+      return handler(req, context)
+    }
+
+    const session = createSession()
+
+    return Response.json(
+      {
+        error: "payment_required",
+        price,
+        session
+      },
+      { status: 402 }
+    )
+  }
+}