cookies-next

Getting, setting and removing cookies with NEXT.JS

• can be used on the client side, anywhere
• can be used for server side rendering in getServerSideProps
• can be used in API handlers

Installation

npm install --save cookies-next

If you are using next.js version greater than 12.2.0 you need to use cookies-next version 2.1.0 or later

Usage

Create a cookie:

import { setCookie } from 'cookies-next';

setCookie('key', 'value', options);

Read a cookie:

import { getCookie } from 'cookies-next';

getCookie('key', options); // => 'value'
getCookie('nothing', options); // => undefined

Read all cookies:

import { getCookies } from 'cookies-next';

getCookies(options); // => { 'name1': 'value1', name2: 'value2' }

Check if a cookie exists:

import { hasCookie } from 'cookies-next';

hasCookie('name', options); // => true
hasCookie('nothing', options); // => false

Delete a cookie:

import { deleteCookie } from 'cookies-next';

deleteCookie(name, options);

IMPORTANT! When deleting a cookie and you're not relying on the default attributes, you must pass the exact same path and domain attributes that were used to set the cookie:

import { deleteCookie } from 'cookies-next';

deleteCookie(name, { path: '/path', domain: '.yourdomain.com' });

Performance

The time complexity of all operations is linear with the number of cookies. For example, under the hood, getCookie calls getCookies. When working reading multiple cookies, it is fastest to use getCookies and inspect the returned object.

Client and Server

If you pass ctx (Next.js context) in function, then this function will be done on both client and server

If the function should be done only on client or can't get ctx, pass null or {} as the first argument to the function and when server side rendering, this function return undefined;

Client Example

import { getCookies, setCookie, deleteCookie } from 'cookies-next';

// we can use it anywhere
getCookies();
getCookie('key');
setCookie('key', 'value');
deleteCookie('key');

SSR Example

/page/index.js

import React from 'react';
import { getCookies, getCookie, setCookie, deleteCookie } from 'cookies-next';

const Home = () => {
  return <div>page content</div>;
};

export const getServerSideProps = ({ req, res }) => {
  setCookie('test', 'value', { req, res, maxAge: 60 * 6 * 24 });
  getCookie('test', { req, res });
  getCookies({ req, res });
  deleteCookie('test', { req, res });

  return { props: {} };
};

export default Home;

API Example

/page/api/example.js

import type { NextApiRequest, NextApiResponse } from 'next';
import { getCookies, getCookie, setCookie, deleteCookie } from 'cookies-next';

export default async function handler(req, res) {
  setCookie('server-key', 'value', { req, res, maxAge: 60 * 60 * 24 });
  getCookie('key', { req, res });
  getCookies({ req, res });
  deleteCookie('key', { req, res });

  return res.status(200).json({ message: 'ok' });
}

API

setCookie(key, value, options);

setCookie('key', 'value', options);

setCookie('key', 'value'); // - client side
setCookie('key', 'value', { req, res }); // - server side

getCookies(options);

getCookies(); // - client side
getCookies({ req, res }); // - server side

getCookie(key, options);

getCookie('key'); - client side
getCookie('key', { req, res }); - server side

hasCookie(key, options);

hasCookie('key'); // - client side
hasCookie('key', { req, res }); // - server side

deleteCookie(key, options);

deleteCookie('key'); // - client side
deleteCookie('key', { req, res }); // - server side

IMPORTANT! When deleting a cookie and you're not relying on the default attributes, you must pass the exact same path and domain attributes that were used to set the cookie:

deleteCookie(ctx, name, { path: '/path', domain: '.yourdomain.com' });  - client side
deleteCookie(ctx, name, { req, res, path: '/path', domain: '.yourdomain.com' }); - server side

key

cookie's name

value

cookie's value

options:

req

required for server side cookies (API and getServerSideProps)

res

required for server side cookies (API and getServerSideProps)

domain

Specifies the value for the Domain Set-Cookie attribute. By default, no domain is set, and most clients will consider the cookie to apply to only the current domain.

encode

Specifies a function that will be used to encode a cookie's value. Since value of a cookie has a limited character set (and must be a simple string), this function can be used to encode a value into a string suited for a cookie's value.

The default function is the global encodeURIComponent, which will encode a JavaScript string into UTF-8 byte sequences and then URL-encode any that fall outside of the cookie range.

expires

A Date object indicating the cookie's expiration date

By default, no expiration is set, and most clients will consider this a "non-persistent cookie" and will delete it on a condition like exiting a web browser application.

note the cookie storage model specification states that if both expires and maxAge are set, then maxAge takes precedence, but it is possible not all clients by obey this, so if both are set, they should point to the same date and time.

httpOnly

Specifies the boolean value for the HttpOnly Set-Cookie attribute. When truthy, the HttpOnly attribute is set, otherwise it is not. By default, the HttpOnly attribute is not set.

note be careful when setting this to true, as compliant clients will not allow client-side JavaScript to see the cookie in document.cookie.

maxAge

Specifies the number (in seconds) to be the value for the Max-Age Set-Cookie attribute. The given number will be converted to an integer by rounding down. By default, no maximum age is set.

note the cookie storage model specification states that if both expires and maxAge are set, then maxAge takes precedence, but it is possible not all clients by obey this, so if both are set, they should point to the same date and time.

path

Specifies the value for the Path Set-Cookie attribute. By default, the path is considered the "default path".

sameSite

Specifies the boolean or string to be the value for the SameSite Set-Cookie attribute.

• true will set the SameSite attribute to Strict for strict same site enforcement.
• false will not set the SameSite attribute.
• 'lax' will set the SameSite attribute to Lax for lax same site enforcement.
• 'none' will set the SameSite attribute to None for an explicit cross-site cookie.
• 'strict' will set the SameSite attribute to Strict for strict same site enforcement.

More information about the different enforcement levels can be found in the specification.

note This is an attribute that has not yet been fully standardized, and may change in the future. This also means many clients may ignore this attribute until they understand it.

secure

Specifies the boolean value for the Secure Set-Cookie attribute. When truthy, the Secure attribute is set, otherwise it is not. By default, the Secure attribute is not set.

note be careful when setting this to true, as compliant clients will not send the cookie back to the server in the future if the browser does not have an HTTPS connection.

License

MIT