Environment Variables

Complete reference for all environment variables used in acodeaday.

Configuration File Location

All environment variables are stored in a single .env file at the project root. Both the backend and frontend read from this file.

Location: .env (project root)

The backend uses pydantic-settings which loads from ../.env (parent directory) first, then .env in the current directory. The frontend uses Vite's envDir configuration to read from the parent directory.

Required Variables

Database

bash

# PostgreSQL connection string (async format required)
DATABASE_URL=postgresql+asyncpg://postgres:postgres@localhost:54322/postgres

Important: Must use postgresql+asyncpg:// (not postgresql://) for async SQLAlchemy.

Local Supabase

Get the connection string from supabase status output (look for "DB URL") and replace postgresql:// with postgresql+asyncpg://.

Supabase Cloud

You must use the Transaction pooler connection string (port 6543), not the direct connection (port 5432):

bash

# ✅ Correct - Transaction pooler (port 6543)
DATABASE_URL=postgresql+asyncpg://postgres.[ref]:[password]@aws-0-[region].pooler.supabase.com:6543/postgres

# ❌ Wrong - Direct connection (port 5432) - will cause connection issues
DATABASE_URL=postgresql+asyncpg://postgres.[ref]:[password]@aws-0-[region].pooler.supabase.com:5432/postgres

To get the correct connection string:

Supabase Dashboard → Settings → Database
Under Connection string, select URI
Choose Transaction pooler (port 6543)
Replace postgresql:// with postgresql+asyncpg://

Supabase Authentication

bash

# Supabase project URL
SUPABASE_URL=http://127.0.0.1:54321

# Supabase anon/public key (for JWT validation)
SUPABASE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...

# Supabase service role key (for admin operations - auto-confirm users)
# Optional but recommended for production to avoid manual email confirmation
SUPABASE_SERVICE_ROLE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...

For local Supabase, these values are available from supabase status after running supabase start.

For Supabase Cloud, get these from Settings → API:

anon public key → SUPABASE_KEY
service_role key → SUPABASE_SERVICE_ROLE_KEY

Default User Credentials

bash

# Default user email (created on backend startup via Supabase Auth)
DEFAULT_USER_EMAIL=admin@acodeaday.local

# Default user password (min 6 characters)
DEFAULT_USER_PASSWORD=changeme123

Important: Change these in production! The backend automatically creates this user on startup if it doesn't exist.

Note: There is no signup flow. Users must either:

Use the default credentials configured above
Create a user manually in the Supabase dashboard

Judge0 Code Execution

bash

# Judge0 CE API endpoint (self-hosted via Docker)
JUDGE0_URL=http://localhost:2358

# Optional: Judge0 API key (for hosted/authenticated Judge0 instances)
JUDGE0_API_KEY=your_api_key_here

For local development, Judge0 runs via Docker Compose on port 2358.

Frontend Variables

Frontend variables must start with VITE_ to be exposed to the browser:

bash

# Backend API URL
VITE_API_URL=http://localhost:8000

# Supabase configuration (must match backend values)
VITE_SUPABASE_URL=http://127.0.0.1:54321
VITE_SUPABASE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...

Optional Variables

Application Settings

bash

# Environment (development, staging, production)
ENVIRONMENT=development

# Debug mode (enables verbose SQL logging)
DEBUG=true

# Log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
LOG_LEVEL=INFO

# Log to file
LOG_TO_FILE=true
LOG_FILE_PATH=logs/acodeaday.log

CORS Configuration

bash

# Comma-separated list of allowed origins for CORS
# For production, set this to your frontend domain(s)
CORS_ORIGINS=http://localhost:3000,http://localhost:5173

Important: In production, set this to your actual frontend domain(s):

bash

# Single domain
CORS_ORIGINS=https://yourdomain.com

# Multiple domains
CORS_ORIGINS=https://yourdomain.com,https://www.yourdomain.com

AI Chat (LLM)

bash

# Comma-separated list of supported LLM models (via litellm)
LLM_SUPPORTED_MODELS=gemini/gemini-2.5-flash,gemini/gemini-2.5-pro,gpt-4o-mini,claude-3-5-sonnet-20241022

# LLM configuration
LLM_MAX_TOKENS=2048
LLM_TEMPERATURE=0.7
LLM_MAX_CONTEXT_TOKENS=8000

# API keys for LLM providers (only needed if using those models)
GOOGLE_API_KEY=your_gemini_key
OPENAI_API_KEY=your_openai_key
ANTHROPIC_API_KEY=your_anthropic_key

Complete .env.example

bash

# =============================================================================
# acodeaday - Environment Variables
# =============================================================================
# Copy this file to .env and fill in your values:
#   cp .env.example .env

# =============================================================================
# Database (Supabase PostgreSQL)
# =============================================================================
DATABASE_URL=postgresql+asyncpg://postgres:postgres@127.0.0.1:54322/postgres

# =============================================================================
# Supabase Authentication
# =============================================================================
SUPABASE_URL=http://127.0.0.1:54321
SUPABASE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZS1kZW1vIiwicm9sZSI6ImFub24iLCJleHAiOjE5ODM4MTI5OTZ9.CRXP1A7WOeoJeXxjNni43kdQwgnWNReilDMblYTn_I0
# SUPABASE_SERVICE_ROLE_KEY=  # Optional: enables auto-confirm for default user

# =============================================================================
# Default User (created on startup)
# =============================================================================
DEFAULT_USER_EMAIL=admin@acodeaday.local
DEFAULT_USER_PASSWORD=changeme123

# =============================================================================
# Judge0 Code Execution
# =============================================================================
JUDGE0_URL=http://localhost:2358
# JUDGE0_API_KEY=  # Optional: for authenticated Judge0 instances

# =============================================================================
# Application Settings
# =============================================================================
ENVIRONMENT=development
DEBUG=true
LOG_LEVEL=INFO
LOG_TO_FILE=true
LOG_FILE_PATH=logs/acodeaday.log

# =============================================================================
# CORS Configuration
# =============================================================================
# Comma-separated list of allowed origins (set to your frontend domain in production)
CORS_ORIGINS=http://localhost:3000,http://localhost:5173,http://localhost:5174

# =============================================================================
# Frontend (VITE_ prefix required)
# =============================================================================
VITE_API_URL=http://localhost:8000
VITE_SUPABASE_URL=http://127.0.0.1:54321
VITE_SUPABASE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZS1kZW1vIiwicm9sZSI6ImFub24iLCJleHAiOjE5ODM4MTI5OTZ9.CRXP1A7WOeoJeXxjNni43kdQwgnWNReilDMblYTn_I0

# =============================================================================
# AI Chat (Optional - only if using AI features)
# =============================================================================
# LLM_SUPPORTED_MODELS=gemini/gemini-2.5-flash,gpt-4o-mini
# GOOGLE_API_KEY=
# OPENAI_API_KEY=
# ANTHROPIC_API_KEY=

How Environment Variables Are Loaded

Backend (pydantic-settings)

The backend uses pydantic-settings for type-safe configuration:

python

from pydantic_settings import BaseSettings, SettingsConfigDict

class Settings(BaseSettings):
    database_url: str = Field(...)
    judge0_url: str = Field("http://localhost:2358")
    # ...

    model_config = SettingsConfigDict(
        env_file=("../.env", ".env"),  # Check parent dir first, then current
        extra="ignore"
    )

settings = Settings()

Access settings in code:

python

from app.config.settings import settings

print(settings.database_url)
print(settings.judge0_url)

Frontend (Vite)

Vite automatically loads .env files and exposes VITE_* variables:

typescript

const apiUrl = import.meta.env.VITE_API_URL
const supabaseUrl = import.meta.env.VITE_SUPABASE_URL

The frontend's vite.config.ts is configured to read from the parent directory:

typescript

export default defineConfig({
  envDir: path.resolve(__dirname, '..'),
  // ...
})

Security Best Practices

1. Never Commit Secrets

Ensure .gitignore includes:

.env
.env.local
.env.*.local

Keep .env.example in the repo (with placeholder values, no real secrets).

2. Use Different Credentials Per Environment

Never reuse production credentials in development/staging.

3. Rotate Secrets Regularly

Change passwords periodically
Rotate API keys after team member changes
Update Supabase keys if compromised

Troubleshooting

"Environment variable not found"

Verify the variable is set in .env
Restart the dev server after adding env vars
For frontend: ensure variable starts with VITE_

Database connection fails

Check DATABASE_URL uses postgresql+asyncpg://
Verify Supabase is running: supabase status
Test connection manually: psql $DATABASE_URL

Judge0 not responding

Verify Judge0 is running: docker compose ps
Test endpoint: curl http://localhost:2358/about
Check container logs: docker compose logs judge0-server

Next Steps

Backend Setup - Set up the FastAPI backend
Frontend Setup - Set up the TanStack frontend
Judge0 Setup - Configure code execution

Environment Variables ​

Configuration File Location ​

Required Variables ​

Database ​

Local Supabase ​

Supabase Cloud ​

Supabase Authentication ​

Default User Credentials ​

Judge0 Code Execution ​

Frontend Variables ​

Optional Variables ​

Application Settings ​

CORS Configuration ​

AI Chat (LLM) ​

Complete .env.example ​

How Environment Variables Are Loaded ​

Backend (pydantic-settings) ​

Frontend (Vite) ​

Security Best Practices ​

1. Never Commit Secrets ​

2. Use Different Credentials Per Environment ​

3. Rotate Secrets Regularly ​

Troubleshooting ​

"Environment variable not found" ​

Database connection fails ​

Judge0 not responding ​

Next Steps ​

Environment Variables

Configuration File Location

Required Variables

Database

Local Supabase

Supabase Cloud

Supabase Authentication

Default User Credentials

Judge0 Code Execution

Frontend Variables

Optional Variables

Application Settings

CORS Configuration

AI Chat (LLM)

Complete .env.example

How Environment Variables Are Loaded

Backend (pydantic-settings)

Frontend (Vite)

Security Best Practices

1. Never Commit Secrets

2. Use Different Credentials Per Environment

3. Rotate Secrets Regularly

Troubleshooting

"Environment variable not found"

Database connection fails

Judge0 not responding

Next Steps