flippercloud/flipper · error · ArgumentError

version should be a string

Error message

version should be a string

What it means

Error "version should be a string" thrown in flippercloud/flipper.

Source

Thrown at lib/flipper/cloud/message_verifier.rb:23

  module Cloud
    class MessageVerifier
      class InvalidSignature < StandardError; end

      DEFAULT_VERSION = "v1"

      def self.header(signature, timestamp, version = DEFAULT_VERSION)
        raise ArgumentError, "timestamp should be an instance of Time" unless timestamp.is_a?(Time)
        raise ArgumentError, "signature should be a string" unless signature.is_a?(String)
        "t=#{timestamp.to_i},#{version}=#{signature}"
      end

      def initialize(secret:, version: DEFAULT_VERSION)
        @secret = secret
        @version = version || DEFAULT_VERSION

        raise ArgumentError, "secret should be a string" unless @secret.is_a?(String)
        raise ArgumentError, "secret should not be empty" if @secret.empty?
        raise ArgumentError, "version should be a string" unless @version.is_a?(String)
      end

      def generate(payload, timestamp)
        raise ArgumentError, "timestamp should be an instance of Time" unless timestamp.is_a?(Time)
        raise ArgumentError, "payload should be a string" unless payload.is_a?(String)

        OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new("sha256"), @secret, "#{timestamp.to_i}.#{payload}")
      end

      def header(signature, timestamp)
        self.class.header(signature, timestamp, @version)
      end

      # Public: Verifies the signature header for a given payload.
      #
      # Raises a InvalidSignature in the following cases:
      # - the header does not match the expected format
      # - no signatures found with the expected scheme

View on GitHub (pinned to 1f86de3ec9)

Solutions

1. Pass the signature version as a String (e.g. 'v1'), matching the version prefix in the signature header
2. Use the default version by not overriding it, or set it to the string documented for your Flipper Cloud webhooks
3. Do not pass a Symbol or Integer for the version option

When it happens

Trigger: Thrown at lib/flipper/cloud/message_verifier.rb:23 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/6b2841768d4f5752. Report an issue: GitHub.