redirect-path

Utility functions for working with URL paths. Primarily used to extract the portion of a callback URL that comes after a given base path—useful in authentication flows, redirects, and multi-tenant routing.

Installation

npm install redirect-path

Usage

import { extractRedirectPath, prependBasePath } from "redirect-path";

const redirectedPath = extractRedirectPath(
  "http://localhost/my/app/tasks/42",
  "/my/app"
);

console.log(redirectedPath);
// "/tasks/42"

const fullPath = prependBasePath("tasks/42", "/my/app");
console.log(fullPath);
// "/my/app/tasks/42"

API Reference

extractRedirectPath(callbackUrl: string, basePath?: string): string

Extracts the portion of the URL path that comes after the base path.

Parameters

| Name | Type | Description | | ------------- | -------- | --------------------------------------------------------------------------------- | | callbackUrl | string | The full URL containing the path you want to extract from. | | basePath | string | Optional base path prefix. If omitted, the function uses NEXT_PUBLIC_BASE_PATH. |

Returns

• A string beginning with / representing the remaining path.
• Returns "" if the base path does not match.

Example

extractRedirectPath("http://localhost/app/users/profile", "/app");
// "/users/profile"

prependBasePath(filePath: string, basePath?: string): string

Safely prefixes a base path to any file or route path.

Parameters

| Name | Type | Description | | ---------- | -------- | ---------------------------------------------- | | filePath | string | Route or file path to append to the base path. | | basePath | string | Optional prefix path. |

Returns

• A normalized path starting with /.

Example

prependBasePath("users/profile", "/app");
// "/app/users/profile"

Why Use This?

• Works with multi-segment base paths
• Handles all slash normalization cases
• Framework-agnostic (Next.js, Express, Node, etc.)
• Reliable for auth flows (callbackUrl), redirects, and rewrites