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Environment Variables Guide

Learn how to use environment variables in your Invoke functions.

Accessing Environment Variables​

module.exports = function(req, res) {
    const apiKey = process.env.API_KEY;
    const debug = process.env.DEBUG === 'true';
    const port = parseInt(process.env.PORT) || 3000;
    
    res.json({ apiKey, debug, port });
};

Setting via Admin Panel​

  1. Navigate to your function in the admin panel
  2. Click "Environment Variables"
  3. Add key-value pairs:
    • API_KEY = your-secret-key
    • DEBUG = true
    • DATABASE_URL = postgresql://...
  4. Click "Save"

Setting via CLI​

node index.js function:deploy \
  --project my-project \
  --name my-function \
  --file function.zip \
  --env API_KEY=secret123 \
  --env DEBUG=true \
  --env MAX_RETRIES=3

Common Patterns​

API Configuration​

module.exports = async function(req, res) {
    const apiUrl = process.env.API_URL || 'https://api.example.com';
    const apiKey = process.env.API_KEY;
    
    if (!apiKey) {
        return res.status(500).json({ error: 'API_KEY not configured' });
    }
    
    const response = await fetch(`${apiUrl}/data`, {
        headers: {
            'Authorization': `Bearer ${apiKey}`
        }
    });
    
    const data = await response.json();
    res.json(data);
};

Database Connection​

module.exports = function(req, res) {
    const dbConfig = {
        host: process.env.DB_HOST || 'localhost',
        port: parseInt(process.env.DB_PORT) || 5432,
        database: process.env.DB_NAME,
        user: process.env.DB_USER,
        password: process.env.DB_PASSWORD
    };
    
    // Connect to database...
    res.json({ configured: true });
};

Feature Flags​

module.exports = function(req, res) {
    const features = {
        newUI: process.env.FEATURE_NEW_UI === 'true',
        betaFeatures: process.env.FEATURE_BETA === 'true',
        maintenance: process.env.MAINTENANCE_MODE === 'true'
    };
    
    if (features.maintenance) {
        return res.status(503).json({ error: 'Under maintenance' });
    }
    
    res.json({ features });
};

Environment-Specific Behavior​

module.exports = function(req, res) {
    const env = process.env.NODE_ENV || 'development';
    
    const config = {
        production: {
            apiUrl: 'https://api.production.com',
            debug: false,
            cacheTimeout: 3600000
        },
        development: {
            apiUrl: 'http://localhost:3000',
            debug: true,
            cacheTimeout: 0
        }
    };
    
    const settings = config[env];
    res.json(settings);
};

Type Conversion​

Strings (default)​

const apiKey = process.env.API_KEY; // string

Numbers​

const port = parseInt(process.env.PORT) || 3000;
const timeout = parseFloat(process.env.TIMEOUT) || 5.5;

Booleans​

const debug = process.env.DEBUG === 'true';
const enabled = process.env.FEATURE_ENABLED !== 'false'; // true by default

Arrays​

// ENV: ALLOWED_ORIGINS=http://localhost:3000,http://example.com
const origins = process.env.ALLOWED_ORIGINS?.split(',') || [];

JSON​

// ENV: CONFIG={"key":"value","enabled":true}
const config = JSON.parse(process.env.CONFIG || '{}');

Validation​

const requiredEnvVars = ['API_KEY', 'API_URL', 'DATABASE_URL'];

module.exports = function(req, res) {
    const missing = requiredEnvVars.filter(key => !process.env[key]);
    
    if (missing.length > 0) {
        return res.status(500).json({
            error: 'Missing required environment variables',
            missing
        });
    }
    
    // Proceed with function logic...
    res.json({ configured: true });
};

Best Practices​

1. Never Hardcode Secrets​

// ❌ DON'T
const apiKey = 'sk_live_abc123xyz';

// ✅ DO
const apiKey = process.env.API_KEY;

2. Provide Defaults​

const timeout = parseInt(process.env.TIMEOUT) || 30000;
const maxRetries = parseInt(process.env.MAX_RETRIES) || 3;

3. Validate Critical Variables​

if (!process.env.API_KEY) {
    return res.status(500).json({ error: 'API_KEY required' });
}

4. Use Descriptive Names​

// ❌ Unclear
process.env.KEY
process.env.URL

// ✅ Clear
process.env.STRIPE_API_KEY
process.env.DATABASE_URL

5. Document Required Variables​

Create a .env.example file:

# API Configuration
API_KEY=your-api-key-here
API_URL=https://api.example.com

# Database
DATABASE_URL=postgresql://user:pass@host:5432/db

# Features (true/false)
DEBUG=false
FEATURE_NEW_UI=true

Security Considerations​

Don't Log Sensitive Data​

// ❌ DON'T
console.log('API Key:', process.env.API_KEY);

// ✅ DO
console.log('API Key configured:', !!process.env.API_KEY);

Don't Return Secrets in Responses​

// ❌ DON'T
res.json({ env: process.env });

// ✅ DO
res.json({ configured: !!process.env.API_KEY });

Next Steps​