withCroct

This higher-order function wraps a Next.js API route handler with the Croct middleware.

If your project already has a Next.js API route handler, you can use this function to configure the Croct middleware while preserving the current handler logic.

It also provides a way to identify and anonymize users for request-based authentication via headers or cookie.

Signature

You can use this function without arguments, which is equivalent to using the middleware function:

function withCroct(): NextApiHandler

Alternatively, you can pass a handler function as the first argument and optionally a user ID resolver function as the second argument:

export function withCroct(next: NextMiddleware, userIdResolver?: UserIdResolver): NextMiddleware;

And lastly, you can pass an options object as a single argument:

export function withCroct(props: CroctMiddlewareOptions): NextMiddleware;

Example

Here is an example of how to use this function:

import {NextResponse} from 'next/server';
import {withCroct} from '@croct/plug-next/middleware';

function log(request) {
  console.log(request.headers.get('user-agent'));

  return NextResponse.next({headers: request.headers});
}

export const middleware = withCroct(log);`

Parameters

The following list describes the supported parameters:

options(optional)

object

The middleware options.

next(optional)

NextMiddleware

The handler function to execute after the Croct middleware.

The function receives the request object and returns a response object.

userIdResolver(optional)

(request: NextRequest)=>Promise<string|null>

A function that resolves the user ID for the current request.

The function receives the request object and returns the user ID as a string or null if the user is anonymous.