koa.md

Koa

At the very beginning of your app.js file, add the following line:

require('@aikidosec/firewall'); // <-- Include this before any other code or imports

const Koa = require("koa");

const app = Koa();

app.use(...);

// ...

or ESM import style:

import "@aikidosec/firewall";

// ...

Zen also supports @koa/router or koa-router.

Blocking mode

By default, the firewall will run in non-blocking mode. When it detects an attack, the attack will be reported to Aikido if the environment variable AIKIDO_TOKEN is set and continue executing the call.

You can enable blocking mode by setting the environment variable AIKIDO_BLOCK to true:

AIKIDO_BLOCK=true node app.js

It's recommended to enable this on your staging environment for a considerable amount of time before enabling it on your production environment (e.g. one week).

Rate limiting and user blocking

If you want to add the rate limiting feature to your app, modify your code like this:

const Zen = require("@aikidosec/firewall");

const app = Koa();

// Optional, if you want to use user based rate limiting or block specific users
app.use(async (ctx, next) => {
  // Get the user from your authentication middleware
  // or wherever you store the user
  Zen.setUser({
    id: "123",
    name: "John Doe", // Optional
  });

  await next();
});

// Place this middleware after your authentication middleware
// As early as possible in the middleware chain
Zen.addKoaMiddleware(app);

app.get(...);

If you are using @koa/router or koa-router, please make sure to place the .use(router.routes()) middleware after the Zen middleware:

Debug mode

If you need to debug the firewall, you can run your express app with the environment variable AIKIDO_DEBUG set to true:

AIKIDO_DEBUG=true node app.js

This will output debug information to the console (e.g. if the agent failed to start, no token was found, unsupported packages, ...).

Preventing prototype pollution

Zen can also protect your application against prototype pollution attacks.

Read Protect against prototype pollution to learn how to set it up.

That's it! Your app is now protected by Zen.
If you want to see a full example, check our koa sample app.