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Development Guide

Flowser application stack consist of frontend Nestjs backend API server, frontend React SPA application and Mongo database.

Environment setup


1. Clone the repo

git clone

2. Install required dependencies

To leverage the power of your favourite IDEs code completion & indexing features, as well as static code analysis with eslint, install required dependencies with bootstrap command (must be run from project root).

cd flowser && npm run bootstrap

3. Configuration

There is no need to configure development environment to get started, as Flowser uses default configuration defined in

However, if you want to use custom configuration, you can do so by defining a separate environment file (e.g. .env.local) and use .env.sample as a template.

4. Run in development

To start the Flowser app in development mode, run dev:start command from project root. This will pull all 3rd party docker images to your local machine, build flowser images and start all application containers.

npm run dev:start

5. View flowser app

Good job! This is the last step, before we can actually start making code changes. Now the app should be running, you can test that by visiting http://localhost:3000.


If something isn't working as expected, try running npm run dev:logs to view logs from all containers or submit a bug report.

Important notes

After installing new NPM library you have to stop docker-compose, remove Docker image, and run docker-compose up again. Below example for frontend:

  1. Stop flowser containers: npm run dev:stop
  2. Remove frontend image: docker rmi frontend:latest
  3. Start flowser containers: npm run dev:start


MongoDB Error: Authentication Failed

You may encounter a bellow MongoDB Authentication error in backend logs. Common root cause of this issue is incorrectly initialised MongoDB database service.

If you started flowser in development or production environment, you can easily solve this issue, by just removing the database/db directory. This will delete all database related files, which will force MongoDB to reinitialise on next container start.

[Nest] 19  - 01/11/2022, 1:48:44 PM   ERROR [TypeOrmModule] Unable to connect to the database. Retrying (7)...
backend-prod | MongoNetworkError: failed to connect to server [database:27017] on first connect [MongoError: Authentication failed.
backend-prod | at Connection.messageHandler (/app/node_modules/mongodb/lib/core/connection/connection.js:364:19)
backend-prod | at Connection.emit (events.js:400:28)
backend-prod | at processMessage (/app/node_modules/mongodb/lib/core/connection/connection.js:456:10)
backend-prod | at Socket.<anonymous> (/app/node_modules/mongodb/lib/core/connection/connection.js:625:15)
backend-prod | at Socket.emit (events.js:400:28)
backend-prod | at addChunk (internal/streams/readable.js:293:12)
backend-prod | at readableAddChunk (internal/streams/readable.js:267:9)
backend-prod | at Socket.Readable.push (internal/streams/readable.js:206:10)
backend-prod | at TCP.onStreamRead (internal/stream_base_commons.js:188:23) {
backend-prod | ok: 0,
backend-prod | code: 18,
backend-prod | codeName: 'AuthenticationFailed'

Development Tools

If you're developing Flowser, bellow tools may come in handy.

MongoDB client

You can use Robo 3T mongodb client app to inspect, debug and edit flowser database.

Connect to Mongo Docker instance with your local machine client using settings in .env.* file that was used for startup - use variables in if you used dev:start command.

Keep in mind that in docker-compose.yml we mapped port 27017 to 27016, use localhost instead of database docker-compose internal host name:



REST API client

You can use Postman or Insomnia API clients to debug and test Flowser REST APIs.

Check out to learn how to import OpenAPI API specification to your client of choice.