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Astra DB Loom

Loom is a thread based chat server, where users can send messages to one or more threads via hashtags (ex. I'm heading to the park at noon #family #friends #frisbee_club ).

60 minutesAdvanced


Astra DB Loom

60 minutes, Advanced, Start Building


Loom is a thread based chat server, where users can send messages to one or more threads via hashtags (ex. "I'm heading to the park at noon #family #friends #frisbee_club" ). Users can subscribe to new threads they see by clicking them and start new threads but just adding a new hashtag to a message.

How this works

The app demonstrates working with DataStax Astra DB, Elixir, and Phoenix Liveviews together. The project attempts to make the best use of this stack. Messages histories are saved and loaded in Astra DB, while new messages are shared via Phoenix channels between all active users in a "thread". The goal is a fast, scalable, and durable chat/messaging application.

Get Started

To build and play with this app, follow the build instructions that are located here:

Running Astra DB Loom

Follow the instructions below to get started.


Let's do some initial setup by creating a serverless(!) database.

DataStax Astra

  1. Create a DataStax Astra account if you don't already have one:


  1. On the home page. Locate the button Create Database


  1. Locate the Get Started button to continue


  1. Define a database name, keyspace name and select a database region, then click create database.


  1. Your Astra DB will be ready when the status will change from Pending to Active 💥💥💥


  1. After your database is provisioned, we need to generate an Application Token for our App. Go to the Settings tab in the database home screen.


  1. Select Admin User for the role for this Sample App and then generate the token. Download the CSV so that we can use the credentials we need later.


  1. After you have your Application Token, head to the database connect screen and copy the connection information that we'll need later. We'll replace ASTRA_DB_APPLICATION_TOKEN with the Token value that is part of your Application Token.



  1. Click Use this template at the top of the GitHub Repository:


  1. Enter a repository name and click 'Create repository from template':


  1. Clone the repository:


🚀 Getting Started Paths:

Make sure you've completed the prerequisites before starting this step

Running on your local machine (Docker)

  1. See for information about launching the astra-loom docker container.

  2. Copy example.env to .env and update it with your Astra DB and Google credentials.

  3. Run the following to setup your environment:

source .env
mix deps.get
cd assets && npm install
mix loom.init
  1. To start the server
source .env
mix phx.server

Running on Gitpod

NOTE: You can skip any Google auth setup on, setting up Google auth on gitpod is beyond the scope of this document.

  1. Click the 'Open in Gitpod' link:

Open in IDE

  1. You will be prompted for the following:
  • "ASTRA_ID" - This is your Astra DB ID, you can find this on the Astra DB web dashboard
  • "ASTRA_REGION" - The region where your Astra DB is hosted, this is also on the Astra DB web dashboard
  • "ASTRA_USERNAME" - The username for you Astra DB
  • "ASTRA_PASSWORD" - The password for your Astra DB username
  1. The webserver should start automatically in a new window or tab of your browser.

  2. Open a terminal and initialize your Astra DB schema with the following command:

mix loom.init
  1. Click "Random Dev User" to login with a random identity and look around.

Datastax contributors

Create your Account and get started!

Let's Go!
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