Environment Variables

Overview

AI Studio uses environment variables to configure database connections, authentication, AI services, and third-party integrations. This guide documents all required and optional environment variables.

Never commit .env.local or any file containing secrets to version control. These files are already included in .gitignore.

Setup Process

Copy the example file

cp .env.example .env.local

Fill in your values

Update each variable with your actual credentials. See sections below for where to obtain each value.

Verify configuration

Start the development server to ensure all variables are correctly configured:

pnpm dev

Required Variables

These variables must be configured for AI Studio to function properly.

Database (Supabase)

DATABASE_URL=postgresql://postgres.xxxx:[email protected]:6543/postgres

Where to get it:

Go to Supabase Dashboard
Select your project → Settings → Database
Copy the Transaction pooler connection string (port 6543)
Use the Transaction mode connection string for serverless compatibility

AI Studio uses Supabase Transaction pooler (port 6543) with prepare: false for compatibility with serverless functions. See lib/db/index.ts:5-6.

Format breakdown:

postgresql://[user]:[password]@[host]:[port]/[database]

Supabase Storage & Authentication

NEXT_PUBLIC_SUPABASE_URL=https://your-project.supabase.co
SUPABASE_SECRET_KEY=sb_secret_your_supabase_secret_key_here

Where to get them:

Supabase Dashboard → Settings → API
Project URL: Copy the URL from “Configuration”
Secret Key: Copy the service_role key under “Project API keys”

The SUPABASE_SECRET_KEY bypasses Row Level Security (RLS). Only use it in server-side code, never expose it to the client.

Authentication (Better Auth)

BETTER_AUTH_SECRET=your_secret_key_here_min_32_characters
BETTER_AUTH_URL=http://localhost:3000
NEXT_PUBLIC_APP_URL=http://localhost:3000

BETTER_AUTH_SECRET:

Used for signing authentication tokens
Must be at least 32 characters long
Generate securely:

openssl rand -base64 32

BETTER_AUTH_URL:

Base URL where your application runs
Local: http://localhost:3000
Production: https://yourdomain.com (no trailing slash)

NEXT_PUBLIC_APP_URL:

Public URL of your application
Used for redirects, emails, and OAuth callbacks
Must match your actual domain

AI Services (Fal.ai)

FAL_API_KEY=your_fal_api_key_here

Where to get it:

Sign up at fal.ai
Go to Dashboard → API Keys
Create a new API key

Pricing: ~$0.039 per image edit (as of 2026) What it’s used for:

AI-powered image generation and editing
Real estate photo enhancement
Style template applications

Email (Resend)

RESEND_API_KEY=re_your_resend_api_key_here

Where to get it:

Sign up at resend.com
Go to API Keys
Create a new API key

What it’s used for:

Team member invitation emails
Password reset emails
Notification emails
Transaction confirmations

Background Jobs (Trigger.dev)

TRIGGER_SECRET_KEY=tr_dev_your_trigger_secret_key

Where to get it:

Sign up at cloud.trigger.dev
Create a new project
Go to Settings → API Keys
Copy your DEV secret key (starts with tr_dev_)

For local development, use the DEV key (tr_dev_). For production deployments, use the PROD key (tr_prod_).

What it’s used for:

AI image generation tasks (background processing)
Long-running workflows
Scheduled jobs
Webhook processing

Development requirement: You must run pnpm trigger in a separate terminal for background jobs to process locally.

Optional Variables

These variables enable additional features but are not required for basic functionality.

Accounting Integration (Fiken)

# FIKEN_API_KEY=your_fiken_api_key_here
# FIKEN_COMPANY_SLUG=your-company-slug

What it’s for:

Norwegian cloud-based accounting system integration
Automated invoicing
Financial reporting

Where to get it:

Sign up at fiken.no
Go to Settings → API
Generate an API key
Find your company slug in your Fiken URL

Fiken integration is specifically designed for Norwegian businesses and is completely optional.

Environment-Specific Configuration

Local Development

.env.local

DATABASE_URL=postgresql://postgres:password@localhost:5432/proppi_dev
BETTER_AUTH_URL=http://localhost:3000
NEXT_PUBLIC_APP_URL=http://localhost:3000
TRIGGER_SECRET_KEY=tr_dev_xxxxxxxxxx  # Use DEV key

Production (Vercel)

Vercel Environment Variables

DATABASE_URL=postgresql://postgres.prod:[email protected]:6543/postgres
BETTER_AUTH_URL=https://yourdomain.com
NEXT_PUBLIC_APP_URL=https://yourdomain.com
TRIGGER_SECRET_KEY=tr_prod_xxxxxxxxxx  # Use PROD key

When deploying to Vercel, add environment variables through the Vercel Dashboard under Settings → Environment Variables. Never commit production secrets.

Variable Reference

Complete alphabetical reference of all environment variables:

Variable	Required	Description	Example
`BETTER_AUTH_SECRET`	Yes	Secret key for signing auth tokens (32+ chars)	`openssl rand -base64 32`
`BETTER_AUTH_URL`	Yes	Base URL where app runs	`http://localhost:3000`
`DATABASE_URL`	Yes	PostgreSQL connection string (Transaction pooler)	`postgresql://user:pass@host:6543/db`
`FAL_API_KEY`	Yes	Fal.ai API key for AI image processing	`fal_xxxxxxxx`
`FIKEN_API_KEY`	No	Fiken accounting API key (Norwegian)	`fik_xxxxxxxx`
`FIKEN_COMPANY_SLUG`	No	Company identifier in Fiken	`my-company`
`NEXT_PUBLIC_APP_URL`	Yes	Public URL (for redirects, emails)	`https://yourdomain.com`
`NEXT_PUBLIC_SUPABASE_URL`	Yes	Supabase project URL	`https://xxx.supabase.co`
`RESEND_API_KEY`	Yes	Resend API key for email delivery	`re_xxxxxxxx`
`SUPABASE_SECRET_KEY`	Yes	Supabase service role key (server-only)	`sb_secret_xxxxx`
`TRIGGER_SECRET_KEY`	Yes	Trigger.dev secret key (dev or prod)	`tr_dev_xxxxxxxx`

Security Best Practices

Never commit secrets to Git

.env.local is already in .gitignore
Use .env.example as a template (without real values)
Review commits before pushing to ensure no secrets leaked

Use different keys per environment

Separate API keys for development and production
Rotate keys regularly (every 90 days recommended)
Revoke old keys after rotation

Restrict API key permissions

Use read-only keys where possible
Limit IP addresses (when supported)
Set spending limits on paid APIs

Public vs Private variables

NEXT_PUBLIC_* variables are exposed to the browser
Never prefix secrets with NEXT_PUBLIC_
Server-only variables (like SUPABASE_SECRET_KEY) are safe

Troubleshooting

Variables Not Loading

Next.js Development
Vercel Deployment
Trigger.dev

Restart the dev server: pnpm dev
Verify file name is exactly .env.local
Check variables are in the root directory
Ensure no syntax errors (no quotes needed)

Variables must be set in Trigger.dev Dashboard
Go to Your Project → Settings → Environment Variables
Add variables separately for dev and prod environments
Redeploy workflows: pnpm trigger:deploy

Common Errors

Error: “DATABASE_URL is not defined”

Verify .env.local exists in root directory
Check spelling: DATABASE_URL (not DATABASE_URI)
Restart dev server after adding variable

Error: “Failed to connect to Supabase”

Use Transaction pooler URL (port 6543, not 5432)
Verify password doesn’t contain special characters that need URL encoding
Check project isn’t paused in Supabase dashboard

Error: “Better Auth secret must be at least 32 characters”

Generate a new secret: openssl rand -base64 32
Ensure no extra spaces or line breaks in .env.local

Error: “Trigger.dev authentication failed”

Use tr_dev_ key for local development
Use tr_prod_ key for production deployments
Verify key is active in Trigger.dev dashboard

Next Steps

Database Setup

Configure PostgreSQL and run migrations with Drizzle ORM

Deployment

Deploy AI Studio to Vercel with proper environment configuration

Setup

Architecture

Guides

Environment Variables

Overview

Setup Process

Required Variables

Database (Supabase)

Supabase Storage & Authentication

Authentication (Better Auth)

AI Services (Fal.ai)

Email (Resend)

Background Jobs (Trigger.dev)

Optional Variables

Accounting Integration (Fiken)

Environment-Specific Configuration

Local Development

Production (Vercel)

Variable Reference

Security Best Practices

Troubleshooting

Variables Not Loading

Common Errors

Next Steps

Database Setup

Deployment

Build docs developers (and LLMs) love

Setup

Architecture

Guides

​Overview

​Setup Process

​Required Variables

​Database (Supabase)

​Supabase Storage & Authentication

​Authentication (Better Auth)

​AI Services (Fal.ai)

​Email (Resend)

​Background Jobs (Trigger.dev)

​Optional Variables

​Accounting Integration (Fiken)

​Environment-Specific Configuration

​Local Development

​Production (Vercel)

​Variable Reference

​Security Best Practices

​Troubleshooting

​Variables Not Loading

​Common Errors

​Next Steps

Database Setup

Deployment

Build docs developers (and LLMs) love

Overview

Setup Process

Required Variables

Database (Supabase)

Supabase Storage & Authentication

Authentication (Better Auth)

AI Services (Fal.ai)

Email (Resend)

Background Jobs (Trigger.dev)

Optional Variables

Accounting Integration (Fiken)

Environment-Specific Configuration

Local Development

Production (Vercel)

Variable Reference

Security Best Practices

Troubleshooting

Variables Not Loading

Common Errors

Next Steps