diff --git a/app/jobs/magellan_rag_query_job.rb b/app/jobs/magellan_rag_query_job.rb
new file mode 100644
index 0000000..5223f80
--- /dev/null
+++ b/app/jobs/magellan_rag_query_job.rb
@@ -0,0 +1,71 @@
+class MagellanRagQueryJob < SlackResponseJob
+  queue_as :default
+
+  VALID_MODELS = [
+    # OpenAI API
+    "gpt-4o".freeze,
+  ]
+
+  DEFAULT_MODEL = ENV.fetch("DEFAULT_MODEL", VALID_MODELS[0])
+
+  class InvalidOptionError < StandardError; end
+
+  Options = Struct.new(
+    :model,
+    keyword_init: true
+  ) do
+    def validate!
+      validate_model! unless model.nil?
+    end
+
+    def validate_model!
+      MagellanRagQueryJob::VALID_MODELS.each do |valid_model|
+        case valid_model
+        when Regexp
+          return if valid_model.match?(model)
+        else
+          return if model == valid_model
+        end
+      end
+      raise InvalidOptionError, "Invalid model is specified: #{model}"
+    end
+  end
+
+  def model_for_message(message)
+    message.conversation.model || DEFAULT_MODEL
+  end
+
+  def perform(params)
+    if params["message_id"].blank?
+      logger.warn "Empty message_id is given"
+      return
+    end
+
+    message = Message.find(params["message_id"])
+    if message.blank?
+      logger.warn "Unable to find Message with id=#{message_id}"
+      return
+    end
+
+    if message.query.present?
+      logger.warn "Message with id=#{message.id} already has its query and response"
+      return
+    end
+
+    options = Options.new(**params.fetch("options", {}))
+
+    begin
+      start_response(message)
+      process_query(message, options)
+    ensure
+      finish_response(message)
+    end
+  rescue Exception => error
+    logger.error "ERROR: #{error.message}"
+    raise unless Rails.env.production?
+  end
+
+  private def process_query(message, options)
+    # TODO: MAGELLAN RAG
+  end
+end
diff --git a/lib/slack_bot/app.rb b/lib/slack_bot/app.rb
index d886765..65cd29c 100644
--- a/lib/slack_bot/app.rb
+++ b/lib/slack_bot/app.rb
@@ -27,6 +27,8 @@ class Application < Sinatra::Base
     end
 
     ALLOW_CHANNEL_IDS = ENV.fetch("ALLOW_CHANNEL_IDS", "").split(/\s+|,\s*/)
+    MAGELLAN_RAG_CHANNEL_IDS = ENV.fetch("MAGELLAN_RAG_CHANNEL_IDS", "").split(/\s+|,\s*/)
+    MAGELLAN_RAG_ENDPOINT = ENV.fetch("MAGELLAN_RAG_ENDPOINT", "localhost:12345")
 
     private def allowed_channel?(channel)
       if ALLOW_CHANNEL_IDS.empty?
@@ -36,6 +38,14 @@ class Application < Sinatra::Base
       end
     end
 
+    private def magellan_rag_channel?(channel)
+      if MAGELLAN_RAG_CHANNEL_IDS.empty?
+        false
+      else
+        MAGELLAN_RAG_CHANNEL_IDS.include?(channel.slack_id)
+      end
+    end
+
     private def thread_allowed_channel?(channel)
       true # channel.thread_allowed?
     end
@@ -61,6 +71,14 @@ class Application < Sinatra::Base
       status 400
     end
 
+    def mention?(event)
+      event["type"] == "app_mention"
+    end
+
+    def direct_message?(event)
+      event["type"] == "message" && event["channel_type"] == "im"
+    end
+
     post "/events" do
       request_data = JSON.parse(request.body.read)
 
@@ -112,14 +130,23 @@ class Application < Sinatra::Base
         #  "event_ts"=>"1679644228.326869"}
         # }}}
 
-        if event["type"] == "app_mention" || (event["type"] == "message" && event["channel_type"] == "im")
+        if mention?(event) || direct_message?(event)
           channel = ensure_conversation(event["channel"])
           user = ensure_user(event["user"], channel)
           ts = event["ts"]
           thread_ts = event["thread_ts"]
           text = event["text"]
 
-          if allowed_channel?(channel)
+          case
+          when magellan_rag_channel?(channel)
+            logger.info "Event:\n" + event.pretty_inspect.each_line.map {|l| "> #{l}" }.join("")
+            logger.info "#{channel.slack_id}: #{text}"
+            if thread_ts and not thread_allowed_channel?(channel)
+              notify_do_not_allowed_thread_context(channel, user, ts)
+            else
+              process_magellan_rag_message(channel, user, ts, thread_ts, text)
+            end
+          when allowed_channel?(channel)
             logger.info "Event:\n" + event.pretty_inspect.each_line.map {|l| "> #{l}" }.join("")
             logger.info "#{channel.slack_id}: #{text}"
 
@@ -322,6 +349,7 @@ class Application < Sinatra::Base
       return unless text =~ /^<@#{bot_id}>\s+/
 
       message_body = Regexp.last_match.post_match
+
       options = process_options(message_body)
       return if options.nil?
 
@@ -376,6 +404,35 @@ class Application < Sinatra::Base
       options
     end
 
+    private def process_magellan_rag_message(channel, user, ts, thread_ts, text)
+      return unless text =~ /^<@#{bot_id}>\s+/
+
+      message_body = Regexp.last_match.post_match
+      options = process_magellan_rag_options(message_body)
+      return if options.nil?
+
+      begin
+        options.validate!
+      rescue MagellanRagQeuryJob::InvalidOptionError => error
+        reply_as_ephemeral(channel, user, ts, error.message)
+        return
+      end
+
+      message = Message.create!(
+        conversation: channel,
+        user: user,
+        text: message_body,
+        slack_ts: ts,
+        slack_thread_ts: thread_ts || ts
+      )
+      MagellanRagQeuryJob.perform_later("message_id" => message.id, "options" => options.to_h)
+    end
+
+    private def process_magellan_rag_options(message_body)
+      # TODO: implement options
+      MagellanRagQeuryJob::Options.new
+    end
+
     private def check_command_permission!(channel, user)
       # TODO
     end