# Project setup complete · A simple Chromia app with Rell and React · Learn Chromia

> Make sure the following are set up before you begin:

Source: https://chromia.com/learn/my-news-feed/setup/

A simple Chromia app with Rell and ReactLesson 2 of 27

1. [01Building a simple Chromia app with Rell, React and FT4](https://chromia.com/learn/my-news-feed/introduction/)
2. [02Project setup complete](https://chromia.com/learn/my-news-feed/setup/)

Module 1: A Rell backend with FT accounts

1. [03Overview](https://chromia.com/learn/my-news-feed/module-one/)
2. [04Part 1: Designing the database schema](https://chromia.com/learn/my-news-feed/module-one/data-modeling/)
3. [05The data model](https://chromia.com/learn/my-news-feed/module-one/data-modeling/tables/)
4. [06Code the model in Rell](https://chromia.com/learn/my-news-feed/module-one/data-modeling/model/)
5. [07Part 2: Set up accounts](https://chromia.com/learn/my-news-feed/module-one/create-accounts/)
6. [08FT4 accounts configuration](https://chromia.com/learn/my-news-feed/module-one/create-accounts/install-configure-ft4/)
7. [09Authentication with FT4 accounts](https://chromia.com/learn/my-news-feed/module-one/create-accounts/authentication/)
8. [10Part 3: A closer look at operations and queries](https://chromia.com/learn/my-news-feed/module-one/operations-queries/)
9. [11Basic operations](https://chromia.com/learn/my-news-feed/module-one/operations-queries/basic-operations/)
10. [12Basic queries](https://chromia.com/learn/my-news-feed/module-one/operations-queries/write-queries/)
11. [13Part 4: Validating and verifying input](https://chromia.com/learn/my-news-feed/module-one/input-verification/)
12. [14Verify inputs](https://chromia.com/learn/my-news-feed/module-one/input-verification/input-verification/)
13. [15Run unit tests](https://chromia.com/learn/my-news-feed/module-one/input-verification/tests/)
14. [16Part 5: How the dapp project is organized](https://chromia.com/learn/my-news-feed/module-one/project-structure/)
15. [17Work with Rell modules](https://chromia.com/learn/my-news-feed/module-one/project-structure/modules/)
16. [18Add modules to your dapp](https://chromia.com/learn/my-news-feed/module-one/project-structure/incorporate-modules/)
17. [19Part 6: Sign up users with an EVM wallet](https://chromia.com/learn/my-news-feed/module-one/register-evm-accounts/)
18. [20Sign up accounts with EVM wallets](https://chromia.com/learn/my-news-feed/module-one/register-evm-accounts/register-evm-accounts/)
19. [21Test the registration](https://chromia.com/learn/my-news-feed/module-one/register-evm-accounts/test-registration/)

Module 2: The React project

1. [22Overview](https://chromia.com/learn/my-news-feed/module-two/)
2. [23Set up the project](https://chromia.com/learn/my-news-feed/module-two/setup/)
3. [24Project scaffold](https://chromia.com/learn/my-news-feed/module-two/scaffold/)
4. [25Connect the client](https://chromia.com/learn/my-news-feed/module-two/connecting-the-client/)
5. [26Summary and manual testing](https://chromia.com/learn/my-news-feed/module-two/summary-and-tests/)

1. [27What is next?](https://chromia.com/learn/my-news-feed/what-next/)

[Learn](https://chromia.com/learn/)[A simple Chromia app with Rell and React](https://chromia.com/learn/my-news-feed/)

02 / 27Beginner

# Project setup complete

Make sure the following are set up before you begin:

PostgreSQL database setup

## Set up PostgreSQL database

Rell needs PostgreSQL 16.3. Without a database, the IDE still works but cannot run a node. You don't need a database to run a console or a remote postchain app.

Rell expects these database settings by default:

* database: `postchain`
* user: `postchain`
* password: `postchain`

## Install

1. Install Homebrew by following the [Homebrew installation guide](https://brew.sh/).
2. Install PostgreSQL:

   shell

   ```
   brew install postgresql@16
   brew services start postgresql@16
   createuser -s postgres
   ```
3. Create and configure the database:

   plsql

   ```nolines
   psql -U postgres -c "CREATE DATABASE postchain WITH TEMPLATE = template0 LC_COLLATE = 'C.UTF-8' LC_CTYPE = 'C.UTF-8' ENCODING 'UTF-8';" -c "CREATE ROLE postchain LOGIN ENCRYPTED PASSWORD 'postchain'; GRANT ALL ON DATABASE postchain TO postchain;"
   ```

   note

   A "peer authentication failed" error means you need to switch the authentication method from `peer` to `md5`. Make this change in the `pg_hba.conf` file of your `psql` database.

1. Install PostgreSQL:

   bash

   ```nolines
   sudo apt install postgresql-16
   ```
2. Create and configure the database:

   bash

   ```nolines
   sudo -u postgres psql -c "CREATE DATABASE postchain WITH TEMPLATE = template0 LC_COLLATE = 'C.UTF-8' LC_CTYPE = 'C.UTF-8' ENCODING 'UTF-8';" -c "CREATE ROLE postchain LOGIN ENCRYPTED PASSWORD 'postchain'; GRANT ALL ON DATABASE postchain TO postchain;"
   ```

1. Install Docker by following the [Docker installation guide](https://docs.docker.com/engine/install/).
2. Create and configure the database:

   dockerfile

   ```nolines
   docker run --name postgres -e POSTGRES_USER=postchain -e POSTGRES_PASSWORD=postchain -p 5432:5432 -d postgres:16.3-alpine3.20
   ```

   note

   The Alpine image of PostgreSQL is used here because its default collation settings are the correct ones. You can also set the collation explicitly through an environment variable:

   bash

   ```nolines
   POSTGRES_INITDB_ARGS="--lc-collate=C.UTF-8 --lc-ctype=C.UTF-8 --encoding=UTF-8"
   ```

1. Get the PostgreSQL installer from the [PostgreSQL download page](https://www.postgresql.org/download/windows/).
2. Run the installer, then add the PostgreSQL folder that holds the binaries to your environment variables. In the Command Prompt (CMD), run the command below. Check that the path points to your binaries and substitute the real version number for the `<version>` placeholder:

   shell

   ```nolines
   setx POSTGRESQL "C:\Program Files\PostgreSQL\<version>\bin"
   ```
3. Close and reopen the Command Prompt (CMD) so the new environment variables take effect. Then run these two commands, one after the other, to create and configure the database:

   plsql

   ```nolines
   psql -U postgres -c "CREATE DATABASE postchain WITH TEMPLATE = template0 LC_COLLATE = 'en_US.UTF-8' LC_CTYPE = 'en_US.UTF-8' ENCODING 'UTF-8';"
   psql -U postgres -c "CREATE ROLE postchain LOGIN ENCRYPTED PASSWORD 'postchain'; GRANT ALL ON DATABASE postchain TO postchain;"
   ```

   note

   Some Windows versions produce permission errors or problems caused by a faulty PostgreSQL installation. If you run into these, install Docker and run PostgreSQL in a container instead.

Install Chromia CLI

## Install Chromia CLI

Follow these steps to install and update the [Chromia CLI](https://gitlab.com/chromaway/core-tools/chromia-cli).

## Prerequisite

You need the following before you start:

* **PostgreSQL database**: Follow [Set up PostgreSQL database](https://docs.chromia.com/get-started/installation/#set-up-postgresql-database).
* **RELL\_JAVA environment**: Chromia CLI runs on a Java runtime, version 21 or later. The package managers handle this dependency for you, so no manual setup is needed. To choose a specific Java runtime for Chromia CLI, set the RELL\_JAVA environment variable to the path of a valid Java installation.

## Installation

Install Chromia CLI through a package manager, or download it directly from [Chromia CLI Packages](https://gitlab.com/chromaway/core-tools/chromia-cli/-/packages).

On macOS, install Chromia CLI (`chr`) as follows:

1. Install Homebrew if you don't already have it:

   bash

   ```nolines
   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   ```
2. Register the Chromia repository with Homebrew:

   bash

   ```nolines
   brew tap chromia/core https://gitlab.com/chromaway/core-tools/homebrew-chromia.git
   ```
3. Install Chromia CLI:

   bash

   ```nolines
   brew install chromia/core/chr
   ```

   info

   To pin a particular version of Chromia CLI, run:

   shell

   ```
   brew install chromia/core/chr@<version>
   brew unlink chr
   brew link chr@<version>
   ```

   Run `brew search chr` to see which versions are available.
4. Confirm the installation by printing the version:

   bash

   ```nolines
   chr --version
   ```

On Linux or WSL (Windows Subsystem for Linux), install Chromia CLI (`chr`) as follows:

1. Fetch Chromia's `apt-repo` public key and add it to your trusted keyrings:

   bash

   ```nolines
   curl -fsSL https://apt.chromia.com/chromia.gpg | sudo tee /usr/share/keyrings/chromia.gpg
   ```
2. Add the Chromia repository to your package sources:

   bash

   ```nolines
   echo "deb [arch=amd64 signed-by=/usr/share/keyrings/chromia.gpg] https://apt.chromia.com stable main" | sudo tee /etc/apt/sources.list.d/chromia.list
   ```
3. Refresh your package sources:

   bash

   ```nolines
   sudo apt-get update
   ```

   info

   If you added `apt.chromia.com` before Chromia CLI version `0.16.0`, run this command so the repository can be updated:

   bash

   ```nolines
   sudo apt-get --allow-releaseinfo-change update
   ```
4. After the update completes, install Chromia CLI:

   bash

   ```nolines
   sudo apt-get install chr
   ```
5. Confirm the installation by printing the version:

   bash

   ```nolines
   chr --version
   ```

On Windows, install Chromia CLI (`chr`) with [Scoop](https://scoop.sh/) as follows:

1. Install Scoop if you don't already have it. Run this in PowerShell as Administrator:

   powershell

   ```nolines
   iwr -useb get.scoop.sh | iex
   ```
2. Add the Chromia bucket to Scoop:

   powershell

   ```nolines
   scoop bucket add chromia https://gitlab.com/chromaway/core-tools/scoop-chromia/
   ```
3. Add the Java bucket to Scoop:

   powershell

   ```nolines
   scoop bucket add java
   ```

   Scoop needs this bucket to fetch openjdk21, which chromia-cli depends on during installation.
4. Install Chromia CLI:

   powershell

   ```nolines
   scoop install chr
   ```
5. Confirm the installation by printing the version:

   powershell

   ```nolines
   chr --version
   ```

## Updating Chromia CLI

Get the newest Chromia CLI from the [package registry](https://gitlab.com/chromaway/core-tools/chromia-cli/-/packages). If you installed it with a package manager, update it with the matching command:

shell

```nolines
brew update
brew upgrade chr
```

shell

```nolines
sudo apt-get update
sudo apt-get install chr
```

shell

```nolines
scoop update
scoop update chr
```

## Docker

You can use Docker to run a standalone Linux container that already includes the Chromia CLI. Set up the [PostgreSQL database](https://docs.chromia.com/get-started/installation/#set-up-postgresql-database) first.

The published images require Docker to be installed and configured on your host. For Windows, Mac, and Linux instructions, see [install Docker](https://docs.docker.com/get-docker/) in the Docker documentation.

### Start the Docker container with Chromia CLI pre-installed

To run the latest Chromia CLI, pass the CLI image name and `chr` to `docker run`:

shell

```nolines
docker run --rm -v $(pwd):/usr/app registry.gitlab.com/chromaway/core-tools/chromia-cli/chr:<latest version> chr
```

Windows Command Prompt Users

The `$(pwd)` syntax doesn't work in Windows Command Prompt (cmd). Use one of the following instead:

* **PowerShell**: `$(Get-Location)` or `$(pwd)`
* **Command Prompt**: `%CD%`

**Command Prompt example:**

cmd

```nolines
docker run --rm -v %CD%:/usr/app registry.gitlab.com/chromaway/core-tools/chromia-cli/chr:<latest version> chr
```

note

Set up your `chromia.yml` file for your platform:

* **Mac**: Set `database:host` to `host.docker.internal`.
* **Windows**: Set `database:host` to `host.docker.internal` (Docker Desktop). If the node still cannot reach your database, try `172.17.0.1`, the default Docker bridge address on Linux.
* **Linux**: Add the `--network=host` argument to your Docker commands.

Without these settings, Chromia CLI cannot connect to the PostgreSQL instance.

To update or remove the Docker image, consult the [Docker command line reference](https://docs.docker.com/engine/reference/commandline/docker/).

bash

```
#!/bin/bash

# Allocate a pseudo-TTY one when run in interactive mode
if [ -t 0 ] && [ -t 1 ] ; then TTY="--tty"; else TTY=""; fi

docker run \
  # Sets the network to host to not need to change the database hostname (linux only)
  --network=host \
  # Set timezone based on system settings (linux only)
  -e TZ=$(cat /etc/timezone) \
  # Sets process ownership to current user
  --user $(id -u):$(id -g) \
  --mount type=bind,source="/etc/passwd",target=/etc/passwd,readonly \
  --mount type=bind,source="/etc/group",target=/etc/group,readonly \
  # Configures ssh-agent (only needed if chr install is called on non-public repositores)
  -e SSH_AUTH_SOCK=$SSH_AUTH_SOCK \
  --volume "$SSH_AUTH_SOCK:$SSH_AUTH_SOCK" \
  --mount type=bind,source="${HOME}/.ssh",target=${HOME}/.ssh,readonly \
  --mount type=bind,source="${HOME}/.config/jgit",target=${HOME}/.config/jgit \
  # Mounts current folder into the container (Use `Get-Location` on PowerShell)
  --mount type=bind,source="$(pwd)",target=/usr/app \
  --interactive ${TTY} \
  --rm \
  registry.gitlab.com/chromaway/core-tools/chromia-cli/chr:${CHR_VERSION:-latest} chr "$@"
```

Windows Command Prompt Users

The bash script above relies on `$(pwd)`, which Windows Command Prompt doesn't support. On Windows:

* **PowerShell**: run the command unchanged; PowerShell also understands `$(pwd)`
* **Command Prompt**: Change `$(pwd)` to `%CD%` in the mount command

**Mount line adjusted for Command Prompt:**

cmd

```nolines
--mount type=bind,source="%CD%",target=/usr/app \
```

## Clone the repository

Get a local copy of the course repository:

shell

```nolines
git clone git@bitbucket.org:chromawallet/news-course.git
```

## Navigate to the project directory

Move into the project folder:

shell

```nolines
cd news-course/rell
```

## Install dependencies

Install the project's dependencies:

shell

```nolines
chr install
```

Written for this site from Chromia’s public course. Code samples are the course’s own.

[← Previous**Building a simple Chromia app with Rell, React and FT4**](https://chromia.com/learn/my-news-feed/introduction/)[Next →**Module 1: A Rell backend with FT accounts**](https://chromia.com/learn/my-news-feed/module-one/)

On this page

* [Install](#install)
* [Prerequisite](#prerequisite)
* [Installation](#installation)
* [Updating Chromia CLI](#updating-chromia-cli)
* [Docker](#docker)
* [Clone the repository](#clone-the-repository)
* [Navigate to the project directory](#navigate-to-the-project-directory)
* [Install dependencies](#install-dependencies)