/Falcon 2.0


Getting Cookies

Cookies can be read from a request either via the get_cookie_values() method or the cookies attribute on the Request object. Generally speaking, the get_cookie_values() method should be used unless you need a collection of all the cookies in the request.

class Resource(object):
    def on_get(self, req, resp):

        cookies = req.cookies

        my_cookie_values = req.get_cookie_values('my_cookie')
        if my_cookie_values:
            # NOTE: If there are multiple values set for the cookie, you
            # will need to choose how to handle the additional values.
            v = my_cookie_values[0]

            # ...

Setting Cookies

Setting cookies on a response may be done either via set_cookie() or append_header().

One of these methods should be used instead of set_header(). With set_header() you cannot set multiple headers with the same name (which is how multiple cookies are sent to the client).

Simple example:

class Resource(object):
    def on_get(self, req, resp):

        # Set the cookie 'my_cookie' to the value 'my cookie value'
        resp.set_cookie('my_cookie', 'my cookie value')

You can of course also set the domain, path and lifetime of the cookie.

class Resource(object):
    def on_get(self, req, resp):
        # Set the maximum age of the cookie to 10 minutes (600 seconds)
        # and the cookie's domain to 'example.com'
        resp.set_cookie('my_cookie', 'my cookie value',
                        max_age=600, domain='example.com')

You can also instruct the client to remove a cookie with the unset_cookie() method:

class Resource(object):
    def on_get(self, req, resp):
        resp.set_cookie('bad_cookie', ':(')

        # Clear the bad cookie

By default, Falcon sets the secure attribute for cookies. This instructs the client to never transmit the cookie in the clear over HTTP, in order to protect any sensitive data that cookie might contain. If a cookie is set, and a subsequent request is made over HTTP (rather than HTTPS), the client will not include that cookie in the request.


For this attribute to be effective, your web server or load balancer will need to enforce HTTPS when setting the cookie, as well as in all subsequent requests that require the cookie to be sent back from the client.

When running your application in a development environment, you can disable this default behavior by setting secure_cookies_by_default to False via API.resp_options. This lets you test your app locally without having to set up TLS. You can make this option configurable to easily switch between development and production environments.

See also: RFC 6265, Section

© 2019 by Falcon contributors
Licensed under the Apache License, Version 2.0.