Environment Configuration

Environment File Setup

Sunschool uses a .env file for configuration. During development, the server loads variables using dotenv. In production (Replit, Railway), environment variables are set directly. From server/config/env.ts:

if (process.env.NODE_ENV === 'development' && !process.env.REPL_ID) {
  try {
    require('dotenv').config();
  } catch (err) {
    console.warn('Optional dependency dotenv not found.');
  }
}

Create Configuration File

cp .env.example .env

The .env.example file from the repository:

# Database connection string
DATABASE_URL="postgresql://postgres:postgres@localhost:5432/postgres"

# OpenRouter API key
OPENROUTER_API_KEY="sk-or-...."

# Session secret for authentication
SESSION_SECRET="your-session-secret"

# JWT token secret
JWT_SECRET="your-jwt-secret"

# Feature flags
# Set to 0 to disable AI features
USE_AI=1
# Set to 0 to disable statistics collection
ENABLE_STATS=1

Required Variables

DATABASE_URL

string

required

PostgreSQL connection string with credentials and database name

Format:

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

Examples:

Neon Serverless
Local PostgreSQL
Railway PostgreSQL

DATABASE_URL="postgresql://user:pass@ep-cool-name-123456.us-east-2.aws.neon.tech/neondb?sslmode=require"

DATABASE_URL="postgresql://sunschool_user:secure_password@localhost:5432/sunschool"

DATABASE_URL="postgresql://postgres:password@containers-us-west-1.railway.app:5432/railway"

From server/config/env.ts:

export const DATABASE_URL = getEnv('DATABASE_URL');
export const DATABASE_SSL = getEnv('DATABASE_SSL', 'true') === 'true';

JWT_SECRET

string

required

Secret key for signing JWT authentication tokens. Defaults to SESSION_SECRET if not provided.

Generate a secure secret:

# Using OpenSSL
openssl rand -base64 32
# Output: XwK9vL2mN8pQ5rT6uY7zA1bC3dE4fG5h

# Using Node.js
node -e "console.log(require('crypto').randomBytes(32).toString('base64'))"

Configuration:

JWT_SECRET="XwK9vL2mN8pQ5rT6uY7zA1bC3dE4fG5h"

From server/config/env.ts:

export const JWT_SECRET = getEnv('JWT_SECRET', SESSION_SECRET);
export const JWT_EXPIRY = getEnv('JWT_EXPIRY', '7d');

Tokens expire after 7 days by default. See Security Configuration for details.

SESSION_SECRET

string

required

Secret for session encryption and cookie signing

SESSION_SECRET="your-session-secret-change-me"

Best practices:

Use different secrets for development and production
Minimum 32 characters
Never commit secrets to version control

From server/config/env.ts:

export const SESSION_SECRET = getEnv('SESSION_SECRET', 'dev-secret-change-me');

The default dev-secret-change-me is insecure. Always set a custom value in production.

OPENROUTER_API_KEY

string

required

API key for OpenRouter (primary AI provider)

Obtain an API key:

Sign up at openrouter.ai
Navigate to Keys
Create a new API key
Copy the key (starts with sk-or-v1-...)

Configuration:

OPENROUTER_API_KEY="sk-or-v1-1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"

From server/config/env.ts:

export const OPENROUTER_API_KEY = process.env.OPENROUTER_API_KEY || '';
export const OPENROUTER_IMAGE_MODEL = process.env.OPENROUTER_IMAGE_MODEL || 'google/gemini-3.1-pro-preview';
export const OPENROUTER_SVG_MODEL = process.env.OPENROUTER_SVG_MODEL || 'google/gemini-3.1-pro-preview';

OpenRouter provides access to multiple models. Sunschool uses:

Lesson generation: Gemini 3.1 Pro
SVG illustrations: Gemini 3.1 Flash

Optional Variables

PERPLEXITY_API_KEY

string

API key for Perplexity (knowledge enrichment)

PERPLEXITY_API_KEY="pplx-1234567890abcdef"

From server/config/env.ts:

export const PERPLEXITY_API_KEY = process.env.PERPLEXITY_API_KEY || '';

Use case: Enriching lesson content with up-to-date information and context.

BITTENSOR_API_KEY (Experimental)

string

API key for Bittensor Subnet 1 (decentralized AI)

BITTENSOR_API_KEY="your-bittensor-key"
BITTENSOR_WALLET_NAME="your-wallet-name"
BITTENSOR_WALLET_HOTKEY="your-wallet-hotkey"
BITTENSOR_SUBNET_1_URL="https://archive.opentensor.ai/graphql"

From server/config/env.ts:

export const BITTENSOR_API_KEY = process.env.BITTENSOR_API_KEY || '';
export const BITTENSOR_SUBNET_1_URL = process.env.BITTENSOR_SUBNET_1_URL || 'https://archive.opentensor.ai/graphql';
export const BITTENSOR_WALLET_NAME = process.env.BITTENSOR_WALLET_NAME;
export const BITTENSOR_WALLET_HOTKEY = process.env.BITTENSOR_WALLET_HOTKEY;

See AI Provider Configuration for Bittensor setup.

PORT

number

default:"5000"

Server listening port

PORT=5000

From server/config/env.ts:

export const PORT = parseInt(getEnv('PORT', '5000'));

NODE_ENV

string

default:"development"

Environment mode: development or production

NODE_ENV=production

From server/config/env.ts:

export const NODE_ENV = getEnv('NODE_ENV', 'development');

Affects:

Logging verbosity
Error detail exposure
SSL requirements

Feature Flags

From server/config/flags.ts:

USE_AI

boolean

default:"1"

Enable/disable AI features entirely. Set to 0 for static fallback content.

USE_AI=1

export const USE_AI = process.env.USE_AI !== '0';

ENABLE_STATS

boolean

default:"1"

Enable statistics collection and analytics

ENABLE_STATS=1

export const ENABLE_STATS = process.env.ENABLE_STATS !== '0';

ENABLE_BITTENSOR_SUBNET_1

boolean

default:"0"

Enable Bittensor as AI provider

ENABLE_BITTENSOR_SUBNET_1=1
BITTENSOR_FALLBACK_ENABLED=1

export const ENABLE_BITTENSOR_SUBNET_1 = process.env.ENABLE_BITTENSOR_SUBNET_1 === '1';
export const BITTENSOR_FALLBACK_ENABLED = process.env.BITTENSOR_FALLBACK_ENABLED !== '0';

Image Generation Flags

ENABLE_SVG_LLM=1
ENABLE_OPENROUTER_IMAGES=1
ENABLE_STABILITY_FALLBACK=0

export const ENABLE_SVG_LLM = process.env.ENABLE_SVG_LLM !== '0';
export const ENABLE_OPENROUTER_IMAGES = process.env.ENABLE_OPENROUTER_IMAGES !== '0';
export const ENABLE_STABILITY_FALLBACK = process.env.ENABLE_STABILITY_FALLBACK === '1';

Advanced Configuration

Image Generation

string

default:"svg-llm"

Primary image generation strategy: svg-llm, openrouter, or stability

IMAGE_PROVIDER=svg-llm
OPENROUTER_IMAGE_MODEL=google/gemini-3.1-pro-preview
OPENROUTER_SVG_MODEL=google/gemini-3.1-pro-preview
IMAGE_GENERATION_TIMEOUT=15000
MAX_IMAGES_PER_LESSON=4

From server/config/env.ts:

export const IMAGE_PROVIDER = process.env.IMAGE_PROVIDER || 'svg-llm';
export const OPENROUTER_IMAGE_MODEL = process.env.OPENROUTER_IMAGE_MODEL || 'google/gemini-3.1-pro-preview';
export const OPENROUTER_SVG_MODEL = process.env.OPENROUTER_SVG_MODEL || 'google/gemini-3.1-pro-preview';
export const IMAGE_GENERATION_TIMEOUT = parseInt(process.env.IMAGE_GENERATION_TIMEOUT || '15000');
export const MAX_IMAGES_PER_LESSON = parseInt(process.env.MAX_IMAGES_PER_LESSON || '4');

Model Fallback Chains

string

Comma-separated list of fallback models for SVG generation

SVG_MODEL_FALLBACKS="google/gemini-3.1-flash-lite-preview,google/gemini-3-flash-preview"
IMAGE_MODEL_FALLBACKS="google/gemini-3.1-flash-image-preview,google/gemini-3-flash-preview"

From server/config/env.ts:

export const SVG_MODEL_FALLBACKS: string[] = (process.env.SVG_MODEL_FALLBACKS || '')
  .split(',').map(s => s.trim()).filter(Boolean);

export const DEFAULT_SVG_MODEL_FALLBACKS = [
  'google/gemini-3.1-flash-lite-preview',
  'google/gemini-3-flash-preview',
];

Fallbacks activate when primary model returns 404 or 402 (insufficient credits).

LLM Provider Selection

string

default:"openrouter"

Primary LLM provider: openrouter, bittensor, or perplexity

LLM_PROVIDER=openrouter

From server/config/env.ts:

export const LLM_PROVIDER = process.env.LLM_PROVIDER || 'openrouter';

Complete Example

Production .env

# ─── Database ───
DATABASE_URL="postgresql://user:pass@ep-cool-name.us-east-2.aws.neon.tech/neondb?sslmode=require"
DATABASE_SSL=true

# ─── Server ───
PORT=5000
NODE_ENV=production

# ─── Authentication ───
JWT_SECRET="XwK9vL2mN8pQ5rT6uY7zA1bC3dE4fG5hIjK6lM7nO8pQ9rS0tU1vW2xY3zA4b"
SESSION_SECRET="A1bC2dE3fG4hI5jK6lM7nO8pQ9rS0tU1vW2xY3zA4bC5dE6fG7hI8jK9lM0n"
JWT_EXPIRY=7d

# ─── AI Providers ───
OPENROUTER_API_KEY="sk-or-v1-abcdef1234567890..."
PERPLEXITY_API_KEY="pplx-1234567890abcdef..."

# ─── Feature Flags ───
USE_AI=1
ENABLE_STATS=1
ENABLE_SVG_LLM=1
ENABLE_OPENROUTER_IMAGES=1

# ─── Image Generation ───
IMAGE_PROVIDER=svg-llm
OPENROUTER_SVG_MODEL=google/gemini-3.1-pro-preview
MAX_IMAGES_PER_LESSON=4
IMAGE_GENERATION_TIMEOUT=15000

Development .env

DATABASE_URL="postgresql://postgres:postgres@localhost:5432/sunschool_dev"
DATABASE_SSL=false

PORT=5000
NODE_ENV=development

JWT_SECRET="dev-jwt-secret-not-for-production"
SESSION_SECRET="dev-session-secret-not-for-production"

OPENROUTER_API_KEY="sk-or-v1-..."

USE_AI=1
ENABLE_STATS=1

Validation

From server/config/env.ts, the getEnv helper throws errors for missing required variables:

export function getEnv(key: string, fallback?: string): string {
  const value = process.env[key];
  if (value === undefined) {
    if (fallback !== undefined) {
      return fallback;
    }
    throw new Error(`Environment variable ${key} is required but not set`);
  }
  return value;
}

Test your configuration:

node -e "require('dotenv').config(); console.log('DATABASE_URL:', process.env.DATABASE_URL?.slice(0, 20) + '...');"
# DATABASE_URL: postgresql://user:pa...

Next Steps

Database Setup

Initialize PostgreSQL and run migrations

AI Providers

Configure OpenRouter, Perplexity, and Bittensor

Security

Implement authentication and access controls

Troubleshooting

Resolve common configuration issues

Deployment

Configuration

Operations

Environment Configuration

Environment File Setup

Create Configuration File

Required Variables

DATABASE_URL

JWT_SECRET

SESSION_SECRET

OPENROUTER_API_KEY

Optional Variables

PERPLEXITY_API_KEY

BITTENSOR_API_KEY (Experimental)

PORT

NODE_ENV

Feature Flags

USE_AI

ENABLE_STATS

ENABLE_BITTENSOR_SUBNET_1

Image Generation Flags

Advanced Configuration

Image Generation

Model Fallback Chains

LLM Provider Selection

Complete Example

Production .env

Development .env

Validation

Next Steps

Database Setup

AI Providers

Security

Troubleshooting

​Environment File Setup

​Create Configuration File

​Required Variables

​DATABASE_URL

​JWT_SECRET

​SESSION_SECRET

​OPENROUTER_API_KEY

​Optional Variables

​PERPLEXITY_API_KEY

​BITTENSOR_API_KEY (Experimental)

​PORT

​NODE_ENV

​Feature Flags

​USE_AI

​ENABLE_STATS

​ENABLE_BITTENSOR_SUBNET_1

​Image Generation Flags

​Advanced Configuration

​Image Generation

​Model Fallback Chains

​LLM Provider Selection

​Complete Example

​Production .env

​Development .env

​Validation

​Next Steps

Database Setup

AI Providers

Security

Troubleshooting

Environment File Setup

Create Configuration File

Required Variables

DATABASE_URL

JWT_SECRET

SESSION_SECRET

OPENROUTER_API_KEY

Optional Variables

PERPLEXITY_API_KEY

BITTENSOR_API_KEY (Experimental)

PORT

NODE_ENV

Feature Flags

USE_AI

ENABLE_STATS

ENABLE_BITTENSOR_SUBNET_1

Image Generation Flags

Advanced Configuration

Image Generation

Model Fallback Chains

LLM Provider Selection

Complete Example

Production .env

Development .env

Validation

Next Steps