1. Quick Guide to Setting Up PostgreSQL on Mac via CLI with Homebrew

Hey, I'm excited to do a series of short articles to set up Free AI tools such as n8n and Ollama on your local machine, or to setup the environment for your personal projects.

One of the first issues you may encounter is that you may not have postgres running on local.

To solve that with the minimal setup follow these exact steps.

Step 1: Install and Start the Service

Open your Mac Terminal and run these commands to install Postgres and keep it running in the background

brew install postgresql # Installs the latest version

brew services start postgresql # Keeps it running in the background

(Optional) You can check if it is running or stop it later using these commands:

brew services list

brew services stop postgresql

Step 2: Connect for the First Time

Homebrew automatically creates a default superuser matching your Mac username with a blank password. You do not need a password yet. Connect directly to the default postgres template database by running:

psql -U $(whoami) -d postgres

Your terminal prompt will change to postgres=#. You are now inside the database engine.

Step 3: Useful Navigation Shortcuts

Inside the Postgres prompt, use these quick slash commands to inspect your setup:
\du -> View all database users.
\l -> View all existing databases (including the default postgres).
\q -> Exit Postgres and return to your regular terminal.

Step 4: Create Your Project Database and User

It is best practice not to use your superuser account for applications. Instead, run these SQL commands inside the prompt to set up a clean environment. Remember the semicolons at the end of each line:

CREATE USER my_project_user WITH PASSWORD 'my_secure_password';

CREATE DATABASE my_project_db;

GRANT ALL PRIVILEGES ON DATABASE my_project_db TO my_project_user;

Note: If you are on Postgres 15 or higher, you might also need to grant schema permissions after connecting to the new DB:
GRANT ALL ON SCHEMA public TO my_project_user;

That’s it! Type \q to exit. You can now connect your application to localhost using your new database, username, and password.