How to use ruby_llm with Cloudflare AI Gateway?

[bubiche]

I plan to use ruby_llm with Cloudflare AI Gateway's OpenAI compatible endpoint with authentication. Can you help me with a few questions please:

1/ I need to set the header cf-aig-authorization with all requests. Looks like I can do it using chat.with_headers but is there a way to do it with RubyLLM.configure in my initializer so I don't have to add the extra header all the time?
2/ If I don't set any API key I get this error: Missing configuration for OpenAI: openai_api_key (RubyLLM::ConfigurationError) so I just set config.openai_api_key = "dummy_key" in my initializer now, is this the recommended way to do this?
3/ I get the Unknown model error when using with_model (openai/gpt-4o-mini, google-ai-studio/gemini-2.0-flash, ... doesn't work). How can I pick my model like with Cloudflare's example: https://developers.cloudflare.com/ai-gateway/usage/chat-completion/
4/ All of this makes me think maybe I should create a new custom provider. How can I do that with ruby-llm?

Thank you for your help.

[nebel95]

I monkeypatched RubyLLM to use it with Cloudflare AI Gateway with RubyLLM. I also use their Bring your own keys (BYOK) feature to manage API keys so I only need to set cf-aig-authorization.

module RubyLLM
  module Providers
    class OpenAI < Provider
      def headers
        {
          "cf-aig-authorization" => "Bearer #{cloudflare_api_token_from_somewhere}",
        }
      end

      class << self
        def configuration_requirements
          []
        end
      end
    end
  end
end

RubyLLM.configure do |config|
  config.openai_api_base = "https://gateway.ai.cloudflare.com/v1/#{account_id}/#{gateway_id}/compat"
  # For Cloudflare AI Gateway to work. Reference: https://github.com/crmne/ruby_llm/pull/381
  config.openai_use_system_role = true
end

[crmne]

you can use .with_headers to remove the need for the monkey patch!