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Using Cloud Firestore in Datastore Mode

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Firestore is a NoSQL document database built for automatic scaling, high performance, and ease of application development. It is the newest version of Datastore and introduces several improvements over Datastore.

Because Firestore in Datastore mode is optimized for server use cases and for App Engine, we recommend using Firestore in Datastore mode for databases that will be used primarily by App Engine apps. Firestore in Native mode is most useful for mobile and real-time notification use cases. For more information about Firestore modes, see Choosing between Native Mode and Datastore mode.

This document describes how to use the Google Cloud Client Library to store and retrieve data in a Datastore mode database.

Prerequisites and setup

Follow the instructions in "Hello, World!" for Ruby on App Engine to set up your environment and project, and to understand how Ruby apps are structured in App Engine. Write down and save your project ID, because you will need it to run the sample application described in this document.

Clone the repository

Download (clone) the sample:

git clone
cd ruby-docs-samples/appengine/datastore

Edit project configuration and set dependencies

In Gemfile, include the google-cloud library, which has the functions for Datastore mode.

source ""

gem "google-cloud-datastore"
gem "sinatra"

Application code

The sample application logs, retrieves, and displays visitor IPs. You can see that a log entry is a simple two-field class that is given the type visit, and is saved to Datastore mode using the save command. Then, the ten most recent visits are retrieved in descending order using the Dataset run command.

require "digest/sha2"
require "sinatra"
require "google/cloud/datastore"

get "/" do
  datastore =

  # Save visit in Datastore
  visit = datastore.entity "Visit" do |v|
    v["user_ip"]   = Digest::SHA256.hexdigest request.ip
    v["timestamp"] =
  end visit

  # Query the last 10 visits from the Datastore
  query     = datastore.query("Visit").order("timestamp", :desc).limit(10)
  visits    = query

  response.write "Last 10 visits:\n"

  visits.each do |visit|
    response.write "Time: #{visit['timestamp']} Addr: #{visit['user_ip']}\n"

  content_type "text/plain"
  status 200

Using index.yaml files

The sample app performs simple queries. More elaborate Datastore mode queries require one or more indexes, which you must specify in an index.yaml file that you upload along with your app. This file may be created manually, or generated automatically while testing your app locally.

Local testing

If you need to develop and test your application locally, you can use the Datastore mode emulator.

For more information

For complete information on Datastore mode, including optimizations and concepts, see the Firestore in Datastore mode documentation.