Environment Variables

Environment variables allow you to configure your applications without hardcoding values in your code.

Overview

Environment variables in Mist are:

• Secure: Values are masked in the UI
• Flexible: Support both build-time and runtime variables
• Easy to Manage: Single and bulk import modes

Adding Environment Variables

Single Variable

1. Navigate to your application
2. Go to Environment tab
3. Click "Add Variable"
4. Select "Single" mode
5. Enter Key and Value
6. Click "Add"

Bulk Import New

Add multiple variables at once by pasting them in KEY=VALUE format:

1. Click "Add Variable"
2. Select "Bulk Paste" mode
3. Paste your environment variables:

NODE_ENV=production
DATABASE_URL=postgresql://user:pass@host:5432/db
API_KEY=your-api-key-here
REDIS_URL=redis://localhost:6379
PORT=3000

4. Preview detected variables
5. Click "Add X Variables"

Supported Formats

The parser supports:

# Standard format
KEY=value

# With quotes
KEY="value with spaces"
KEY='single quoted value'

# Comments (ignored)
# This is a comment
DATABASE_URL=postgres://localhost

# Empty lines (ignored)

NEXT_PUBLIC_API=https://api.example.com

Variable Types

Runtime Variables

Available when your container runs:

// Node.js
const apiKey = process.env.API_KEY;

// Python
import os
api_key = os.environ.get('API_KEY')

Build-time Variables

Available during the build process:

ARG NODE_ENV
RUN npm run build

Editing Variables

1. Find the variable in the list
2. Click the Edit icon (pencil)
3. Modify key or value
4. Click "Save"

Deleting Variables

1. Find the variable in the list
2. Click the Delete icon (trash)
3. Confirm deletion

WARNING

Changes to environment variables require redeployment to take effect.

Common Use Cases

Database Connection

DATABASE_URL=postgresql://user:password@host:5432/dbname
DB_HOST=localhost
DB_PORT=5432
DB_NAME=myapp
DB_USER=appuser
DB_PASSWORD=secret123

API Keys

STRIPE_API_KEY=sk_test_xxxxx
SENDGRID_API_KEY=SG.xxxxx
AWS_ACCESS_KEY_ID=AKIAXXXXX
AWS_SECRET_ACCESS_KEY=xxxxx

Application Configuration

NODE_ENV=production
PORT=3000
LOG_LEVEL=info
SESSION_SECRET=random-secret-string

Feature Flags

ENABLE_ANALYTICS=true
ENABLE_BETA_FEATURES=false
MAINTENANCE_MODE=false

Best Practices

Security

• ✅ Never commit secrets to Git
• ✅ Use environment variables for all sensitive data
• ✅ Rotate API keys regularly
• ✅ Use different values for staging and production

Naming Conventions

# Use UPPER_SNAKE_CASE
DATABASE_URL=...

# Prefix public variables (Next.js, Vite, etc.)
NEXT_PUBLIC_API_URL=...
VITE_API_URL=...

# Group related variables
AWS_REGION=us-east-1
AWS_BUCKET=my-bucket
AWS_ACCESS_KEY_ID=...

Organization

# Database
DATABASE_URL=...
DATABASE_POOL_SIZE=10

# Redis
REDIS_URL=...
REDIS_TTL=3600

# External Services
STRIPE_KEY=...
SENDGRID_KEY=...

# App Config
NODE_ENV=production
PORT=3000

Coming Soon

🚧 Planned Features

Future enhancements for environment variables:

• Encryption at Rest - Encrypted storage for sensitive values
• Variable Groups - Organize variables into reusable groups
• Templates - Pre-defined variable sets for common stacks
• Version History - Track changes to variables over time
• Import/Export - Download as .env file
• Secrets Management - Integration with Vault or similar
• Variable Validation - Ensure required variables are set

Troubleshooting

Variables Not Available

Problem: Environment variables not accessible in application

Solutions:

• Redeploy the application after adding variables
• Check variable names (case-sensitive)
• Verify the variable is not overridden elsewhere

Build Failing

Problem: Build fails after adding variables

Solutions:

• Check for special characters in values
• Use quotes for values with spaces
• Ensure variables don't conflict with system variables

Parsing Errors (Bulk Import)

Problem: Some variables not detected

Solutions:

• Ensure format is KEY=VALUE
• Keys must start with letter or underscore
• Keys can only contain letters, numbers, and underscores
• Remove invalid characters

Examples by Framework

Node.js / Express

NODE_ENV=production
PORT=3000
DATABASE_URL=postgresql://localhost/myapp
SESSION_SECRET=your-secret-key

Next.js

# Server-side
DATABASE_URL=postgresql://localhost/myapp

# Client-side (must be prefixed)
NEXT_PUBLIC_API_URL=https://api.example.com

Python / Django

DJANGO_SECRET_KEY=your-secret-key
DEBUG=False
DATABASE_URL=postgresql://localhost/myapp
ALLOWED_HOSTS=example.com,www.example.com

Go

PORT=8080
DATABASE_URL=postgresql://localhost/myapp
JWT_SECRET=your-jwt-secret

API Reference

Manage environment variables programmatically via the API:

• Create Variable
• List Variables
• Update Variable
• Delete Variable