flippercloud/flipper · error · ArgumentError

Flipper::Cloud url must use https but was #{value.inspect}.

Error message

Flipper::Cloud url must use https but was #{value.inspect}. https is required so your token is never sent in cleartext.

What it means

Error "Flipper::Cloud url must use https but was #{value.inspect}. https is required so your token is never sent in cleartext." thrown in flippercloud/flipper.

Source

Thrown at lib/flipper/cloud/url_validator.rb:18

require "uri"

module Flipper
  module Cloud
    module UrlValidator
      def self.validate(value)
        url = value.to_s.dup
        uri = URI(url)

        return url.freeze if uri.is_a?(URI::HTTPS) && !uri.host.to_s.empty?

        raise_invalid_url(value)
      rescue URI::InvalidURIError
        raise_invalid_url(value)
      end

      def self.raise_invalid_url(value)
        raise ArgumentError,
          "Flipper::Cloud url must use https but was #{value.inspect}. " \
          "https is required so your token is never sent in cleartext."
      end
      private_class_method :raise_invalid_url
    end
    private_constant :UrlValidator
  end
end

View on GitHub (pinned to 1f86de3ec9)

Solutions

1. Change the Flipper Cloud URL to use https:// instead of http://
2. Remove the custom URL override to use the default https endpoint
3. If testing against a local mock, do so only in test config, never production

When it happens

Trigger: Thrown at lib/flipper/cloud/url_validator.rb:18 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of flippercloud/flipper@1f86de3ec9 (2026-08-23). Data as JSON: /api/errors/ce8eea847a660353. Report an issue: GitHub.