configs on instance levels might be nicer?

[getand]

Would it make sense to allow to inject configurations into clients as having it on the class level is not so cool for mocking since you cannot use dependency injection?

[johannesengl]

This would be possible by overriding the Client#build_request(url, **opts) method.
It would be possible to do something like this:

    def build_request(url, **opts)
      url = "#{config[:api_url]}/#{url}"
      opts = opts.deep_merge!({ "headers" => {"Authorization" => "Bearer #{config[:api_token]}"}}) # Add a header to all requests
      opts = opts.deep_merge({"params" => {"token" => config[:project_token]}}) # Add a query param to all requests

      Typhoeus::Request.new(url, **opts.symbolize_keys)
    end

What do you think?