Bot protection reference
Arcjet bot detection allows you to manage traffic by automated clients and bots.
Configuration
Bot detection is configured by allowing or denying a subset of bots. The allow
and deny lists are mutually-exclusive, such that using allow will result in
a DENY decision for any detected bot that is not specified in the allow list
and using deny will result in an ALLOW decision for any detected bot that is
not specified in the deny list.
You can use only one of the following configuration definitions:
type BotOptionsAllow = { mode?: "LIVE" | "DRY_RUN"; allow: Array<ArcjetWellKnownBot | ArcjetBotCategory>;};type BotOptionsDeny = { mode?: "LIVE" | "DRY_RUN"; deny: Array<ArcjetWellKnownBot | ArcjetBotCategory>;};The arcjet client is configured with one or more detectBot rules which take
one or many BotOptions.
Allowing specific bots
Most applications want to block almost all bots. However, it is common to allow some bots to access your system, such as bots for search indexing or API access from the command line.
This behavior is configured with an allow list from our full list of
bots and/or bot
categories.
import arcjet, { detectBot } from "@arcjet/node";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});import arcjet, { detectBot } from "@arcjet/node";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export async function handle({ event, resolve }) { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import arcjet, { detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // Google has multiple crawlers, each with a different user-agent, so we // allow the entire Google category "CATEGORY:GOOGLE", "CURL", // allows the default user-agent of the `curl` tool "DISCORD_CRAWLER", // allows Discordbot ], }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return NextResponse.json( { error: "You are a bot!", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }, { status: 403 }, ); }
return NextResponse.json({ message: "Hello world", });}Denying specific bots
Some applications may only want to block a small subset of bots, while allowing the majority continued access. This may be due to many reasons, such as misconfigured or high-traffic bots.
This behavior is configured with a deny list from our full list of
bots and/or bot
categories.
import arcjet, { detectBot } from "@arcjet/node";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});import arcjet, { detectBot } from "@arcjet/node";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export async function handle({ event, resolve }) { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req); console.log("Decision", decision);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req); console.log("Decision", decision);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return NextResponse.json( { error: "You are a bot!", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }, { status: 403 }, ); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to deny from // https://arcjet.com/bot-list - all other detected bots will be allowed deny: [ "CATEGORY:AI", // denies all detected AI and LLM scrapers "CURL", // denies the default user-agent of the `curl` tool ], }), ],});
export async function POST(req) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return NextResponse.json( { error: "You are a bot!", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }, { status: 403 }, ); }
return NextResponse.json({ message: "Hello world", });}Per route vs hooks
Bot protection rules can be configured in two ways:
- Per route: The rule is defined in the route handler itself. This allows you to configure the rule alongside the code it is protecting which is useful if you want to use the decision to add context to your own code. However, it means rules are not located in a single place.
- Hooks: The rule is defined as a hook. This allows you to configure rules in a single place or apply them globally to all routes, but it means the rules are not located alongside the code they are protecting.
Per route
This configures bot protection on a single route.
import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, json, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(event: RequestEvent) { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, { message: "Forbidden" }); }
return json({ message: "Hello world" });}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, json } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(event) { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, { message: "Forbidden" }); }
return json({ message: "Hello world" });}Hooks
This will run on every request to your SvelteKit app - see the SvelteKit Hooks docs for details.
import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // Block all bots except search engine crawlers. See the full list of bots // for other options: https://arcjet.com/bot-list allow: ["CATEGORY:SEARCH_ENGINE"], }), ],});
export async function handle({ event, resolve }) { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "Forbidden"); }
return resolve(event);}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // Block all bots except search engine crawlers. See the full list of bots // for other options: https://arcjet.com/bot-list allow: ["CATEGORY:SEARCH_ENGINE"], }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "Forbidden"); }
return resolve(event);}Avoiding double protection with hooks
If you use Arcjet in hooks and individual routes, you need to be careful that Arcjet is not running multiple times per request. This can be avoided by excluding the individual routes before running Arcjet in the hook.
For example, if you already have rules defined in the API route
at /api/arcjet, you can exclude it from the hook like this:
import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { // Ignore routes that extend the Arcjet rules // - they will call `.protect` themselves const filteredRoutes = ["/api/arcjet"]; if (filteredRoutes.includes(event.url.pathname)) { // return - route will handle protecttion return resolve(event); }
const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "Forbidden"); }
return resolve(event);}Per route vs middleware
Bot protection rules can be configured in two ways:
- Per API route: The rule is defined in the API route itself. This allows you to configure the rule alongside the code it is protecting which is useful if you want to use the decision to add context to your own code. However, it means rules are not located in a single place.
- Middleware: The rule is defined in the middleware. This allows you to configure rules in a single place or apply them globally to all routes, but it means the rules are not located alongside the code they are protecting.
Per route
This configures bot protection on a single route.
import arcjet, { sensitiveInfo } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ sensitiveInfo({ deny: ["EMAIL"], mode: "LIVE", }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isSensitiveInfo()) { return res .status(400) .json({ error: "Unexpected sensitive info received" }); // Returning the reason is useful for debugging, but don't return it to the // client in production // .json({ error: "You are suspicious!", reason: decision.reason }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { sensitiveInfo } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ sensitiveInfo({ deny: ["EMAIL"], mode: "LIVE", }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isSensitiveInfo()) { return res .status(400) .json({ error: "Unexpected sensitive info received" }); // Returning the reason is useful for debugging, but don't return it to the // client in production // .json({ error: "You are suspicious!", reason: decision.reason }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { sensitiveInfo } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ sensitiveInfo({ deny: ["EMAIL"], mode: "LIVE", }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isSensitiveInfo()) { return NextResponse.json( { error: "Unexpected sensitive info received", // Useful for debugging, but don't return it to the client in // production //reason: decision.reason, }, { status: 400 }, ); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { sensitiveInfo } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ sensitiveInfo({ deny: ["EMAIL"], mode: "LIVE", }), ],});
export async function POST(req) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isSensitiveInfo()) { return NextResponse.json( { error: "Unexpected sensitive info received", // Useful for debugging, but don't return it to the client in // production //reason: decision.reason, }, { status: 400 }, ); }
return NextResponse.json({ message: "Hello world", });}Middleware
This will run on every request to your Next.js app, except for static assets
(configured in the matcher - see the Next.js
docs
for details).
Create a file called middleware.ts in your project root (at the same level as
pages or app or inside src):
import arcjet, { createMiddleware, detectBot } from "@arcjet/next";export const config = { // matcher tells Next.js which routes to run the middleware on. // This runs the middleware on all routes except for static assets. matcher: ["/((?!_next/static|_next/image|favicon.ico).*)"],};const aj = arcjet({ key: process.env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // Block all bots except search engine crawlers. See the full list of bots // for other options: https://arcjet.com/bot-list allow: ["CATEGORY:SEARCH_ENGINE"], }), ],});// Pass any existing middleware with the optional existingMiddleware propexport default createMiddleware(aj);You can also customize the response depending on the decision. In this case we will return a 403 Forbidden response only if we detect a hosting provider IP address for the bot detection rule result:
import arcjet, { detectBot } from "@arcjet/next";import { NextRequest, NextResponse } from "next/server";
export const config = { // matcher tells Next.js which routes to run the middleware on. // This runs the middleware on all routes except for static assets. matcher: ["/((?!_next/static|_next/image|favicon.ico).*)"],};const aj = arcjet({ key: process.env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only allow: [], // "allow none" will block all detected bots }), ],});
export default async function middleware(request: NextRequest) { const decision = await aj.protect(request);
if ( // If the decision is deny because the request is from a bot and the bot IP // address is from a known hosting provider, then block the request decision.isDenied() && decision.reason.isBot() && decision.ip.isHosting() ) { return NextResponse.json({ error: "Unauthorized" }, { status: 403 }); } else { return NextResponse.next(); }}Create a file called middleware.js in your project root (at the same level as
pages or app or inside src):
import arcjet, { createMiddleware, detectBot } from "@arcjet/next";export const config = { // matcher tells Next.js which routes to run the middleware on. // This runs the middleware on all routes except for static assets. matcher: ["/((?!_next/static|_next/image|favicon.ico).*)"],};const aj = arcjet({ key: process.env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // Block all bots except search engine crawlers. See the full list of bots // for other options: https://arcjet.com/bot-list allow: ["CATEGORY:SEARCH_ENGINE"], }), ],});// Pass any existing middleware with the optional existingMiddleware propexport default createMiddleware(aj);You can also customize the response depending on the decision. In this case we will return a 403 Forbidden response only if we detect a hosting provider IP address for the bot detection rule result:
import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
export const config = { // matcher tells Next.js which routes to run the middleware on. // This runs the middleware on all routes except for static assets. matcher: ["/((?!_next/static|_next/image|favicon.ico).*)"],};const aj = arcjet({ key: process.env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only allow: [], // "allow none" will block all detected bots }), ],});
export default async function middleware(request) { const decision = await aj.protect(request);
if ( // If the decision is deny because the request is from a bot and the bot IP // address is from a known hosting provider, then block the request decision.isDenied() && decision.reason.isBot() && decision.ip.isHosting() ) { return NextResponse.json({ error: "Unauthorized" }, { status: 403 }); } else { return NextResponse.next(); }}Avoiding double protection with middleware
If you use Arcjet in middleware and individual routes, you need to be careful that Arcjet is not running multiple times per request. This can be avoided by excluding the API route from the middleware matcher.
For example, if you already have a bot detection rule defined in the API route
at /api/hello, you can exclude it from the middleware by specifying a matcher
in /middleware.ts:
import arcjet, { createMiddleware, detectBot } from "@arcjet/next";export const config = { // The matcher prevents the middleware executing on static assets and the // /api/hello API route because you already installed Arcjet directly matcher: ["/((?!_next/static|_next/image|favicon.ico|api/hello).*)"],};const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});// Pass any existing middleware with the optional existingMiddleware propexport default createMiddleware(aj);Decision
The quick start example will deny requests that match the bot detection rules, immediately returning a response to the client.
Arcjet also provides a single protect function that is used to execute your
protection rules. This requires a request argument which is the request
context as passed to the request handler.
This function returns a Promise that resolves to an
ArcjetDecision object. This contains the following properties:
id(string) - The unique ID for the request. This can be used to look up the request in the Arcjet dashboard. It is prefixed withreq_for decisions involving the Arcjet cloud API. For decisions taken locally, the prefix islreq_.conclusion(ArcjetConclusion) - The final conclusion based on evaluating each of the configured rules. If you wish to accept Arcjet’s recommended action based on the configured rules then you can use this property.reason(ArcjetReason) - An object containing more detailed information about the conclusion.results(ArcjetRuleResult[]) - An array ofArcjetRuleResultobjects containing the results of each rule that was executed.ip(ArcjetIpDetails) - An object containing Arcjet’s analysis of the client IP address. See the SDK reference for more information.
You check if a deny conclusion has been returned by a bot protection rule by
using decision.isDenied() and decision.reason.isBot() respectively.
You can iterate through the results and check whether a bot protection rule was applied:
for (const result of decision.results) { console.log("Rule Result", result);}This example will log the full result as well as the bot protection rule:
import { env } from "$env/dynamic/private";import arcjet, { detectBot, fixedWindow } from "@arcjet/sveltekit";import { error, json, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(event: RequestEvent) { const decision = await aj.protect(event); console.log("Arcjet decision", decision);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return error(403, "Forbidden"); }
return json({ message: "Hello world" });}import { env } from "$env/dynamic/private";import arcjet, { detectBot, fixedWindow } from "@arcjet/sveltekit";import { error, json } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(event) { const decision = await aj.protect(event); console.log("Arcjet decision", decision);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return error(403, "Forbidden"); }
return json({ message: "Hello world" });}import arcjet, { detectBot, fixedWindow } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req); console.log("Arcjet decision", decision);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot, fixedWindow } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req); console.log("Arcjet decision", decision);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { fixedWindow, detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, // Limiting by ip.src is the default if not specified //characteristics: ["ip.src"], rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return NextResponse.json({ error: "Forbidden" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { fixedWindow, detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, // Limiting by ip.src is the default if not specified //characteristics: ["ip.src"], rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(req) { const decision = await aj.protect(req);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return NextResponse.json({ error: "Forbidden" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { fixedWindow, detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, // Limiting by ip.src is the default if not specified //characteristics: ["ip.src"], rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req); console.log("Decision", decision);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return res .status(403) .json({ error: "Forbidden", reason: decision.reason }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { fixedWindow, detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, // Limiting by ip.src is the default if not specified //characteristics: ["ip.src"], rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req); console.log("Decision", decision);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { return res .status(403) .json({ error: "Forbidden", reason: decision.reason }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { fixedWindow, detectBot } from "@arcjet/node";import http from "node:http";
const aj = arcjet({ key: process.env.ARCJET_KEY, // Get your site key from https://app.arcjet.com characteristics: ["ip.src"], rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
const server = http.createServer(async function (req, res) { const decision = await aj.protect(req);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { if (decision.reason.isRateLimit()) { res.writeHead(429, { "Content-Type": "application/json" }); res.end( JSON.stringify({ error: "Too Many Requests", reason: decision.reason }), ); res.end(JSON.stringify({ error: "Forbidden" })); } else { res.writeHead(403, { "Content-Type": "application/json" }); res.end(JSON.stringify({ error: "Forbidden" })); } } else { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ message: "Hello world" })); }});
server.listen(8000);import arcjet, { fixedWindow, detectBot } from "@arcjet/node";import http from "node:http";
const aj = arcjet({ key: process.env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com characteristics: ["ip.src"], rules: [ fixedWindow({ mode: "LIVE", window: "1h", max: 60, }), detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
const server = http.createServer(async function ( req: http.IncomingMessage, res: http.ServerResponse,) { const decision = await aj.protect(req);
for (const result of decision.results) { console.log("Rule Result", result);
if (result.reason.isRateLimit()) { console.log("Rate limit rule", result); }
if (result.reason.isBot()) { console.log("Bot protection rule", result); } }
if (decision.isDenied()) { if (decision.reason.isRateLimit()) { res.writeHead(429, { "Content-Type": "application/json" }); res.end( JSON.stringify({ error: "Too Many Requests", reason: decision.reason }), ); res.end(JSON.stringify({ error: "Forbidden" })); } else { res.writeHead(403, { "Content-Type": "application/json" }); res.end(JSON.stringify({ error: "Forbidden" })); } } else { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ message: "Hello world" })); }});
server.listen(8000);Identified bots
The decision also contains all of the identified
bots and matched categories detected from the
request. A request may be identified as zero, one, or more bots/categories—all
of which will be available on the decision.allowed and decision.denied
properties.
import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only allow: [], // "allow none" will block all detected bots }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only allow: [], // "allow none" will block all detected bots }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return res.status(403).json({ error: "Forbidden" }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return NextResponse.json({ error: "You are a bot!" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(req) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return NextResponse.json({ error: "You are a bot!" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return res.status(403).json({ error: "Forbidden" }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return res.status(403).json({ error: "Forbidden" }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return NextResponse.json({ error: "You are a bot!" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function POST(req) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return NextResponse.json({ error: "You are a bot!" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return res.status(403).json({ error: "Forbidden" }); }
res.status(200).json({ name: "Hello world" });}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function handle({ event, resolve }) { const decision = await aj.protect(event);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { const decision = await aj.protect(event);
if (decision.reason.isBot()) { console.log("detected + allowed bots", decision.reason.allowed); console.log("detected + denied bots", decision.reason.denied); }
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}Error handling
Arcjet is designed to fail open so that a service issue or misconfiguration does
not block all requests. The SDK will also time out and fail open after 1000ms
when NODE_ENV or ARCJET_ENV is development and 500ms otherwise. However,
in most cases, the response time will be less than 20-30ms.
If there is an error condition, Arcjet will return an
ERROR type and you can check the reason property for more information, like
accessing decision.reason.message.
import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, json, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(event: RequestEvent) { const decision = await aj.protect(event);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return error(503, { message: "Service unavailable" }); }
if (decision.isDenied()) { return error(403, { message: "You are a bot!" }); }
return json({ message: "Hello world" });}import { env } from "$env/dynamic/private";import arcjet, { detectBot } from "@arcjet/sveltekit";import { error, json } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(event) { const decision = await aj.protect(event);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return error(503, { message: "Service unavailable" }); }
if (decision.isDenied()) { return error(403, { message: "You are a bot!" }); }
return json({ message: "Hello world" });}import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return new Response("Service unavailable", { status: 503 }); }
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return new Response("Service unavailable", { status: 503 }); }
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { detectBot } from "@arcjet/node";import http from "node:http";
const aj = arcjet({ key: process.env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only allow: [], // "allow none" will block all detected bots }), ],});
const server = http.createServer(async function (req, res) { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //res.writeHead(503, { "Content-Type": "application/json" }); //res.end(JSON.stringify({ error: "Service unavailable" })); }
if (decision.isDenied()) { res.writeHead(403, { "Content-Type": "application/json" }); res.end(JSON.stringify({ error: "Forbidden" })); } else { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ message: "Hello world" })); }});
server.listen(8000);import arcjet, { detectBot } from "@arcjet/node";import http from "node:http";
const aj = arcjet({ key: process.env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only allow: [], // "allow none" will block all detected bots }), ],});
const server = http.createServer(async function ( req: http.IncomingMessage, res: http.ServerResponse,) { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //res.writeHead(503, { "Content-Type": "application/json" }); //res.end(JSON.stringify({ error: "Service unavailable" })); }
if (decision.isDenied()) { res.writeHead(403, { "Content-Type": "application/json" }); res.end(JSON.stringify({ error: "Forbidden" })); } else { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ message: "Hello world" })); }});
server.listen(8000);import arcjet, { detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return res.status(503).json({ error: "Service unavailable" }); }
if (decision.isDenied()) { return res.status(403).json({ error: "You are a bot!", }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return res.status(503).json({ error: "Service unavailable" }); }
if (decision.isDenied()) { return res.status(403).json({ error: "You are a bot!", }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(req) { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return NextResponse.json({ error: "Service unavailable" }, { status: 503 }); }
if (decision.isDenied()) { return NextResponse.json( { error: "You are a bot!", }, { status: 403 }, ); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(req: Request) { const decision = await aj.protect(req);
// If the request is missing a User-Agent header, the decision will be // marked as an error! You should check for this and make a decision about // the request since requests without a User-Agent could indicate a crafted // request from an automated client. if (decision.isErrored()) { // Fail open by logging the error and continuing console.warn("Arcjet error", decision.reason.message); // You could also fail closed here if the request is missing a User-Agent //return NextResponse.json({ error: "Service unavailable" }, { status: 503 }); }
if (decision.isDenied()) { return NextResponse.json( { error: "You are a bot!", }, { status: 403, }, ); }
return NextResponse.json({ message: "Hello world", });}Filtering categories
All categories are also provided as enumerations, which allows for programmatic
access. For example, you may want to allow most of CATEGORY:GOOGLE except
their “advertising quality” bot.
import arcjet, { botCategories, detectBot } from "@arcjet/node";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});import arcjet, { botCategories, detectBot } from "@arcjet/node";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});import arcjet, { botCategories, detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { botCategories, detectBot } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req);
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import { env } from "$env/dynamic/private";import arcjet, { botCategories, detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import { env } from "$env/dynamic/private";import arcjet, { botCategories, detectBot } from "@arcjet/sveltekit";import { error, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export async function handle({ event, resolve,}: { event: RequestEvent; resolve: (event: RequestEvent) => Response | Promise<Response>;}): Promise<Response> { const decision = await aj.protect(event);
if (decision.isDenied()) { return error(403, "You are a bot!"); }
return resolve(event);}import arcjet, { botCategories, detectBot } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { botCategories, detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return res.status(403).json({ error: "Forbidden", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { botCategories, detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return NextResponse.json( { error: "You are a bot!", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }, { status: 403 }, ); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { botCategories, detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", // configured with a list of bots to allow from // https://arcjet.com/bot-list - all other detected bots will be blocked allow: [ // filter a category to remove individual bots from our provided lists ...botCategories["CATEGORY:GOOGLE"].filter( (bot) => bot !== "GOOGLE_ADSBOT" && bot !== "GOOGLE_ADSBOT_MOBILE", ), ], }), ],});
export async function POST(req) { const decision = await aj.protect(req);
if (decision.isDenied() && decision.reason.isBot()) { return NextResponse.json( { error: "You are a bot!", // Useful for debugging, but don't return these to the client in // production denied: decision.reason.denied, }, { status: 403 }, ); }
return NextResponse.json({ message: "Hello world", });}Testing
Arcjet runs the same in any environment, including locally and in CI. You can
use the mode set to DRY_RUN to log the results of rule execution without
blocking any requests.
We have an example test framework you can use to automatically test your rules. Arcjet can also be triggered based using a sample of your traffic.
See the Testing section of the docs for details.
Examples
Protecting a page
You can protect a Next.js page from bots by calling the Arcjet SDK from within the page loader:
Protecting an app router page within the handler itself is not currently supported, but you can set up a matcher on the middleware instead:
import arcjet, { createMiddleware, detectBot } from "@arcjet/next";export const config = { // The matcher runs just on the /hello pages route matcher: ["/hello"],};const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});// Pass any existing middleware with the optional existingMiddleware propexport default createMiddleware(aj);Protecting an app router page within the handler itself is not currently supported, but you can set up a matcher on the middleware instead:
import arcjet, { createMiddleware, detectBot } from "@arcjet/next";export const config = { // The matcher runs just on the /hello pages route matcher: ["/hello"],};const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});// Pass any existing middleware with the optional existingMiddleware propexport default createMiddleware(aj);import arcjet, { detectBot } from "@arcjet/next";import Error from "next/error";import Head from "next/head";import React from "react";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "DRY_RUN", allow: [], // "allow none" will block all detected bots }), ],});
// getServerSideProps is called on the server before rendering the pageexport const getServerSideProps = async (context) => { const decision = await aj.protect(context.req); console.log("decision", decision);
if (decision.isDenied()) { return { props: { pageProps: { errorCode: 403, errorText: "Access denied" } }, }; }
return { props: { pageProps: { errorCode: false, errorText: "" } } };};
export default function Page({ pageProps }) { // If there is an error, render the Next.js error page if (pageProps.errorCode) { return ( <Error statusCode={pageProps.errorCode} title={pageProps.errorText} /> ); } return ( <> <Head> <title>Page</title> <meta name="viewport" content="width=device-width, initial-scale=1" /> </Head> <main> <div> <h2>Hello</h2> </div> </main> </> );}import arcjet, { detectBot } from "@arcjet/next";import type { GetServerSideProps, InferGetServerSidePropsType } from "next";import Error from "next/error";import Head from "next/head";import React from "react";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "DRY_RUN", allow: [], // "allow none" will block all detected bots }), ],});
type pageProps = { errorCode: number | false; errorText: string;};
// getServerSideProps is called on the server before rendering the pageexport const getServerSideProps = (async (context) => { const decision = await aj.protect(context.req); console.log("decision", decision);
if (decision.isDenied()) { return { props: { pageProps: { errorCode: 403, errorText: "Access denied" } }, }; }
return { props: { pageProps: { errorCode: false, errorText: "" } } };}) satisfies GetServerSideProps<{ pageProps: pageProps;}>;
export default function Page({ pageProps,}: InferGetServerSidePropsType<typeof getServerSideProps>) { // If there is an error, render the Next.js error page if (pageProps.errorCode) { return ( <Error statusCode={pageProps.errorCode} title={pageProps.errorText} /> ); } return ( <> <Head> <title>Page</title> <meta name="viewport" content="width=device-width, initial-scale=1" /> </Head> <main> <div> <h2>Hello</h2> </div> </main> </> );}Wrap existing handler
All the examples on this page show how you can inspect the decision to control
what to do next. However, if you just wish to send a generic 403 Forbidden
response you can delegate this to Arcjet by wrapping your handler withArcjet.
For both the Node or Edge runtime:
import arcjet, { detectBot, withArcjet } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export const GET = withArcjet(aj, async (req: Request) => { return NextResponse.json({ message: "Hello world", });});For both the Node or Edge runtime:
import arcjet, { detectBot, withArcjet } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export const GET = withArcjet(aj, async (req) => { return NextResponse.json({ message: "Hello world", });});For the Node (default) runtime:
import arcjet, { detectBot, withArcjet } from "@arcjet/next";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default withArcjet(aj, async (req, res) => { res.status(200).json({ name: "Hello world" });});For the Edge runtime:
import arcjet, { detectBot, withArcjet } from "@arcjet/next";import { NextResponse } from "next/server";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default withArcjet(aj, async (req) => { return NextResponse.json({ message: "Hello world", });});For the Node (default) runtime:
import arcjet, { detectBot, withArcjet } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default withArcjet( aj, async (req: NextApiRequest, res: NextApiResponse) => { res.status(200).json({ name: "Hello world" }); },);For the Edge runtime:
import arcjet, { detectBot, withArcjet } from "@arcjet/next";import { NextRequest, NextResponse } from "next/server";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default withArcjet(aj, async (req: NextRequest) => { return NextResponse.json({ message: "Hello world", });});Edge Functions
Arcjet works in Edge Functions and with the Edge Runtime.
import arcjet, { detectBot } from "@arcjet/next";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req);
if (decision.isDenied()) { return res.status(403).json({ error: "You are a bot!" }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req);
if (decision.isDenied()) { return res.status(403).json({ error: "You are a bot!" }); }
res.status(200).json({ name: "Hello world" });}import arcjet, { detectBot } from "@arcjet/next";import { NextRequest, NextResponse } from "next/server";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY!, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export default async function handler(req: NextRequest, res: NextResponse) { const decision = await aj.protect(req);
if (decision.isDenied()) { return NextResponse.json( { error: "You are a bot!", }, { status: 403, }, ); }
return NextResponse.json({ message: "Hello world", });}import arcjet, { detectBot } from "@arcjet/next";import { NextResponse } from "next/server";
export const config = { runtime: "edge",};
const aj = arcjet({ key: process.env.ARCJET_KEY, rules: [ detectBot({ mode: "LIVE", allow: [], // "allow none" will block all detected bots }), ],});
export async function GET(req) { const decision = await aj.protect(req);
if (decision.isDenied()) { return NextResponse.json( { error: "You are a bot!", }, { status: 403, }, ); }
return NextResponse.json({ message: "Hello world", });}