Environment variables: where settings and secrets live
Create your first .env.local file, use a harmless public value from it on your site, prove which values reach the browser and which stay on the server, and find the screen where Vercel keeps the same values.
Why this matters
In Module 7, your kitchen gets its first keys: the address of Adjoa's database and a key that lets the website talk to it. Later you'll add a key for sending emails. Those keys have to live somewhere. Not in your code, because your code goes to GitHub. Not in an AI chat. Not on a sticky note.
They live in environment variables: named settings that sit next to your project instead of inside it. Every professional project uses them, and every hosting service, Vercel included, has a screen for them.
Today you'll practise with a value that isn't secret at all: Adjoa's (placeholder) WhatsApp number. That way, if you make a mistake, nothing bad can happen. You'll also run a small experiment that shows, with your own eyes, the single most important rule about these values: anything starting with NEXT_PUBLIC_ is visible to every visitor. Get that rule into your bones now, and you'll never accidentally publish a key.
In the full lesson
- The idea in plain English
- Do it
- Check it worked
- Understand what AI wrote
- Quick check
- What you can do now
The step-by-step, the prompt to copy, the video and the check-it-worked list, for every lesson in all 15 modules. GHS 399 ($40), paid once by mobile money or card, yours to keep.