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Environment Variables Guide

Learn how to use environment variables in your Invoke functions.

Accessing Environment Variables​

export default function handler(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​

invoke function:deploy \
  --project my-project \
  --name my-function \
  --env API_KEY=secret123 \
  --env DEBUG=true \
  --env MAX_RETRIES=3

Common Patterns​

API Configuration​

export default async function handler(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​

export default function handler(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
  }

  res.json({ configured: true })
}

Feature Flags​

export default function handler(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​

export default function handler(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 }
  }

  res.json(config[env] || config.development)
}

Type Conversion​

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']

export default function handler(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
    })
  }

  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
KEY=...
URL=...

# ✅ Clear
STRIPE_API_KEY=...
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​