[Dashboard] Add Cloudflare Turnstile to Faucet page (thirdweb-dev#5067)

## Problem solved

Short description of the bug fixed or feature added

<!-- start pr-codex -->

---

## PR-Codex overview
This PR introduces support for Cloudflare Turnstile captcha validation in the faucet functionality of the dashboard application, enhancing security during fund claims. It also updates dependencies and configuration for the new feature.

### Detailed summary
- Added `TURNSTILE_SITE_KEY` constant to `env.ts`.
- Updated `package.json` to include `@marsidev/react-turnstile`.
- Modified `.env.example` to add `NEXT_PUBLIC_TURNSTILE_SITE_KEY` and `TURNSTILE_SECRET_KEY`.
- Updated `next.config.js` to allow scripts from Cloudflare.
- Enhanced `POST` handler in `route.ts` to validate `turnstileToken`.
- Updated `FaucetButton.tsx` to integrate Turnstile captcha and form handling.
- Introduced `claimFaucetSchema` for form validation using `zod`.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}`

<!-- end pr-codex -->

apps/dashboard/.env.example

@@ -96,4 +96,8 @@ UNTHREAD_PRO_TIER_ID=""
 NEXT_PUBLIC_DEMO_ENGINE_URL=""
 
 # API server secret (required for thirdweb.com SIWE login). Copy from Vercel.
-API_SERVER_SECRET=""
+API_SERVER_SECRET=""
+
+# Used for the Faucet page (/<chain_id>)
+NEXT_PUBLIC_TURNSTILE_SITE_KEY=""
+TURNSTILE_SECRET_KEY=""

apps/dashboard/next.config.js

@@ -8,7 +8,7 @@ const ContentSecurityPolicy = `
   style-src 'self' 'unsafe-inline' vercel.live;
   font-src 'self' vercel.live assets.vercel.com framerusercontent.com;
   frame-src * data:;
-  script-src 'self' 'unsafe-eval' 'unsafe-inline' 'wasm-unsafe-eval' 'inline-speculation-rules' *.thirdweb.com *.thirdweb-dev.com vercel.live js.stripe.com framerusercontent.com events.framer.com;
+  script-src 'self' 'unsafe-eval' 'unsafe-inline' 'wasm-unsafe-eval' 'inline-speculation-rules' *.thirdweb.com *.thirdweb-dev.com vercel.live js.stripe.com framerusercontent.com events.framer.com challenges.cloudflare.com;
   connect-src * data: blob:;
   worker-src 'self' blob:;
   block-all-mixed-content;

apps/dashboard/package.json

@@ -29,6 +29,7 @@
     "@emotion/react": "11.13.3",
     "@emotion/styled": "11.13.0",
     "@hookform/resolvers": "^3.9.0",
+    "@marsidev/react-turnstile": "^1.0.2",
     "@n8tb1t/use-scroll-position": "^2.0.3",
     "@radix-ui/react-alert-dialog": "^1.1.2",
     "@radix-ui/react-avatar": "^1.1.1",

apps/dashboard/src/@/constants/env.ts

@@ -23,3 +23,6 @@ export const DASHBOARD_STORAGE_URL =
 
 export const API_SERVER_URL =
   process.env.NEXT_PUBLIC_THIRDWEB_API_HOST || "https://api.thirdweb.com";
+
+export const TURNSTILE_SITE_KEY =
+  process.env.NEXT_PUBLIC_TURNSTILE_SITE_KEY || "";

apps/dashboard/src/app/(dashboard)/(chain)/[chain_id]/(chainPage)/components/client/FaucetButton.tsx

@@ -2,17 +2,24 @@
 
 import { Spinner } from "@/components/ui/Spinner/Spinner";
 import { Button } from "@/components/ui/button";
-import { THIRDWEB_ENGINE_FAUCET_WALLET } from "@/constants/env";
+import { Form, FormControl, FormField, FormItem } from "@/components/ui/form";
+import {
+  THIRDWEB_ENGINE_FAUCET_WALLET,
+  TURNSTILE_SITE_KEY,
+} from "@/constants/env";
 import { useThirdwebClient } from "@/constants/thirdweb.client";
 import { CustomConnectWallet } from "@3rdweb-sdk/react/components/connect-wallet";
+import { Turnstile } from "@marsidev/react-turnstile";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import type { CanClaimResponseType } from "app/api/testnet-faucet/can-claim/CanClaimResponseType";
 import { mapV4ChainToV5Chain } from "contexts/map-chains";
 import { useTrack } from "hooks/analytics/useTrack";
+import { useForm } from "react-hook-form";
 import { toast } from "sonner";
 import { toUnits } from "thirdweb";
 import type { ChainMetadata } from "thirdweb/chains";
 import { useActiveAccount, useWalletBalance } from "thirdweb/react";
+import { z } from "zod";
 
 function formatTime(seconds: number) {
   const rtf = new Intl.RelativeTimeFormat("en", { numeric: "auto" });
@@ -29,6 +36,12 @@ function formatTime(seconds: number) {
   return rtf.format(+seconds, "second");
 }
 
+const claimFaucetSchema = z.object({
+  turnstileToken: z.string().min(1, {
+    message: "Captcha validation is required.",
+  }),
+});
+
 export function FaucetButton({
   chain,
   amount,
@@ -52,7 +65,7 @@ export function FaucetButton({
   const queryClient = useQueryClient();
 
   const claimMutation = useMutation({
-    mutationFn: async () => {
+    mutationFn: async (turnstileToken: string) => {
       trackEvent({
         category: "faucet",
         action: "claim",
@@ -67,6 +80,7 @@ export function FaucetButton({
         body: JSON.stringify({
           chainId: chainId,
           toAddress: address,
+          turnstileToken,
         }),
       });
 
@@ -117,6 +131,8 @@ export function FaucetButton({
     faucetWalletBalanceQuery.data !== undefined &&
     faucetWalletBalanceQuery.data.value < toUnits("1", 17);
 
+  const form = useForm<z.infer<typeof claimFaucetSchema>>();
+
   // loading state
   if (faucetWalletBalanceQuery.isPending || canClaimFaucetQuery.isPending) {
     return (
@@ -161,28 +177,46 @@ export function FaucetButton({
     );
   }
 
+  const claimFunds = (values: z.infer<typeof claimFaucetSchema>) => {
+    // Instead of having a dedicated endpoint (/api/verify-token),
+    // we can just attach the token in the payload and send it to the claim-faucet endpoint, to avoid a round-trip request
+    const claimPromise = claimMutation.mutateAsync(values.turnstileToken);
+    toast.promise(claimPromise, {
+      success: `${amount} ${chain.nativeCurrency.symbol} sent successfully`,
+      error: `Failed to claim ${amount} ${chain.nativeCurrency.symbol}`,
+    });
+  };
+
   // eligible to claim and faucet has balance
   return (
     <div className="flex w-full flex-col text-center">
-      <Button
-        variant="primary"
-        className="w-full gap-2"
-        onClick={() => {
-          const claimPromise = claimMutation.mutateAsync();
-          toast.promise(claimPromise, {
-            success: `${amount} ${chain.nativeCurrency.symbol} sent successfully`,
-            error: `Failed to claim ${amount} ${chain.nativeCurrency.symbol}`,
-          });
-        }}
-      >
-        {claimMutation.isPending ? (
-          <>
-            Claiming <Spinner className="size-3" />
-          </>
-        ) : (
-          `Get ${amount} ${chain.nativeCurrency.symbol}`
-        )}
-      </Button>
+      <Form {...form}>
+        <form onSubmit={form.handleSubmit(claimFunds)}>
+          <Button variant="primary" className="w-full gap-2" type="submit">
+            {claimMutation.isPending ? (
+              <>
+                Claiming <Spinner className="size-3" />
+              </>
+            ) : (
+              `Get ${amount} ${chain.nativeCurrency.symbol}`
+            )}
+          </Button>
+          <FormField
+            control={form.control}
+            name="turnstileToken"
+            render={({ field }) => (
+              <FormItem>
+                <FormControl>
+                  <Turnstile
+                    siteKey={TURNSTILE_SITE_KEY}
+                    onSuccess={(token) => field.onChange(token)}
+                  />
+                </FormControl>
+              </FormItem>
+            )}
+          />
+        </form>
+      </Form>
 
       {faucetWalletBalanceQuery.data && (
         <p className="mt-3 text-muted-foreground text-xs">

apps/dashboard/src/app/api/testnet-faucet/claim/route.ts

@@ -11,12 +11,15 @@ const THIRDWEB_ACCESS_TOKEN = process.env.THIRDWEB_ACCESS_TOKEN;
 interface RequestTestnetFundsPayload {
   chainId: number;
   toAddress: string;
+
+  // Cloudflare Turnstile token received from the client-side
+  turnstileToken: string;
 }
 
 // Note: This handler cannot use "edge" runtime because of Redis usage.
 export const POST = async (req: NextRequest) => {
   const requestBody = (await req.json()) as RequestTestnetFundsPayload;
-  const { chainId, toAddress } = requestBody;
+  const { chainId, toAddress, turnstileToken } = requestBody;
   if (Number.isNaN(chainId)) {
     throw new Error("Invalid chain ID.");
   }
@@ -46,6 +49,42 @@ export const POST = async (req: NextRequest) => {
     );
   }
 
+  if (!turnstileToken) {
+    return NextResponse.json(
+      {
+        error: "Missing Turnstile token.",
+      },
+      { status: 400 },
+    );
+  }
+
+  // https://developers.cloudflare.com/turnstile/get-started/server-side-validation/
+  // Validate the token by calling the "/siteverify" API endpoint.
+  const result = await fetch(
+    "https://challenges.cloudflare.com/turnstile/v0/siteverify",
+    {
+      body: JSON.stringify({
+        secret: process.env.TURNSTILE_SECRET_KEY,
+        response: turnstileToken,
+        remoteip: ipAddress,
+      }),
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+    },
+  );
+
+  const outcome = await result.json();
+  if (!outcome.success) {
+    return NextResponse.json(
+      {
+        error: "Could not validate captcha.",
+      },
+      { status: 400 },
+    );
+  }
+
   const ipCacheKey = `testnet-faucet:${chainId}:${ipAddress}`;
   const addressCacheKey = `testnet-faucet:${chainId}:${toAddress}`;