How-To Guide

How to Set Up Railway Environment Variables

Manage secrets and configuration in Railway

TL;DR

TL;DR: Click your service in Railway, go to the Variables tab, and add key-value pairs. Railway automatically redeploys when you save. Use variable references ( $ ) to share values between services. Use Shared Variables for project-wide secrets.

Step-by-Step Setup

Open your project

Go to railway.app/dashboard and click on your project.

Select your service

Click on the service you want to configure (e.g., your web app, API, or database).

Navigate to Variables

Click the Variables tab in the service panel.

Add variables

You have two options:

Add individually: Click "New Variable" and enter key/value
Raw Editor: Click "RAW Editor" to paste multiple variables at once

# In Raw Editor, paste like a .env file:
DATABASE_URL=postgresql://...
STRIPE_SECRET_KEY=sk_test_xxxxx
OPENAI_API_KEY=sk-xxxxx

Save and deploy

Railway automatically triggers a redeploy when you save variables. You'll see the deployment start in the Deployments tab.

Railway-Specific Features

Variable References

Railway lets you reference variables from other services using the ${{SERVICE.VAR}} syntax:

# Reference the database URL from your Postgres service
DATABASE_URL=${{Postgres.DATABASE_URL}}

# Reference another service's variable
API_URL=${{api.RAILWAY_PUBLIC_DOMAIN}}

Built-in Railway Variables

Railway provides several built-in variables automatically:

# Available in every service
RAILWAY_ENVIRONMENT=production
RAILWAY_PUBLIC_DOMAIN=your-app.up.railway.app
RAILWAY_PRIVATE_DOMAIN=your-app.railway.internal
RAILWAY_PROJECT_ID=xxx
RAILWAY_SERVICE_ID=xxx

Shared Variables

For variables needed across multiple services:

Click on "Shared Variables" at the project level
Add your variable (e.g., STRIPE_SECRET_KEY)
In each service, reference it: STRIPE_SECRET_KEY=${{shared.STRIPE_SECRET_KEY}}

Pro tip: Use Shared Variables for API keys that multiple services need. This way you only update the key in one place when rotating.

Using the Railway CLI

# Link to your project
railway link

# List variables for current service
railway variables

# Add a variable
railway variables set STRIPE_SECRET_KEY=sk_test_xxxxx

# Get a specific variable
railway variables get DATABASE_URL

# Delete a variable
railway variables delete OLD_KEY

# Run local dev with Railway variables
railway run npm run dev

Common Variable Patterns

# Database (auto-populated when adding Railway Postgres)
DATABASE_URL=${{Postgres.DATABASE_URL}}

# Redis (auto-populated when adding Railway Redis)
REDIS_URL=${{Redis.REDIS_URL}}

# Internal service communication
API_INTERNAL_URL=http://${{api.RAILWAY_PRIVATE_DOMAIN}}:3000

# External URL for webhooks
WEBHOOK_URL=https://${{RAILWAY_PUBLIC_DOMAIN}}/api/webhook

# Secrets (use Shared Variables)
STRIPE_SECRET_KEY=${{shared.STRIPE_SECRET_KEY}}
OPENAI_API_KEY=${{shared.OPENAI_API_KEY}}

Private vs Public Domains

RAILWAY_PRIVATE_DOMAIN is for internal service-to-service communication (faster, no internet). RAILWAY_PUBLIC_DOMAIN is your public URL. Use private domains when services talk to each other within Railway.

Do I need to restart after changing variables?

No, Railway automatically triggers a new deployment when you save variable changes. The new deployment will have the updated values.

How do I use Railway variables locally?

Use railway run to run commands with your Railway environment variables. For example: railway run npm run dev. This injects all your service's variables into the local process.

Can I have different variables for staging and production?

Yes, Railway supports environments. You can create a "staging" environment and set different variable values for each environment. Click on "Environments" in your project to manage them.