Environment Variables

Pcnaid MCP Hub uses environment variables for configuration. This guide covers all available variables and their usage.

Core Application Settings

Server Configuration

Variable	Default	Description
`PORT`	`3000`	Port number for the HTTP server
`INIT_TIMEOUT`	`300000`	Initial timeout for the application
`BASE_PATH`	`''`	The base path of the application
`READONLY`	`false`	Set to `true` to enable readonly mode
`MCPHUB_SETTING_PATH`		Path to the Pcnaid MCP Hub settings
`NODE_ENV`	`development`	Application environment (`development`, `production`, `test`)

PORT=3000
INIT_TIMEOUT=300000
BASE_PATH=/api
READONLY=true
MCPHUB_SETTING_PATH=/path/to/settings
NODE_ENV=production

Authentication & Security

Admin Password

Variable	Default	Description
`ADMIN_PASSWORD`	(random)	Password for the default `admin` user. If not set, a cryptographically random 24-character password is generated on first launch and printed to the server logs.

ADMIN_PASSWORD=your-secure-admin-password

JWT Configuration

Variable	Default	Description
`JWT_SECRET`	-	Secret key for JWT token signing (required)

JWT_SECRET=your-super-secret-key-change-this-in-production

Smart Routing & Embeddings

Embedding Configuration

Variable	Type	Default	Description
`SMART_ROUTING_ENABLED`	`boolean`	`false`	Enable the smart routing feature
`EMBEDDING_MODEL`	`string`	`text-embedding-3-small`	Embedding model name used for vector search
`AZURE_OPENAI_EMBEDDING_MODEL`	`string`	`text-embedding-3-small`	The actual OpenAI model name deployed in Azure (e.g. `text-embedding-3-small`). Azure deployment names are arbitrary identifiers, so this field tells Pcnaid MCP Hub which OpenAI model is behind the deployment, enabling correct token-limit enforcement and tokenizer selection. Only used when `SMART_ROUTING_EMBEDDING_PROVIDER=azure_openai`.
`EMBEDDING_MAX_TOKENS`	`number`	By model	Maximum tokens for text truncation before generating embeddings. Overrides the per-model default. Useful to match the `batch_size` of a local inference server (e.g. LocalAI, LM Studio). When unset, the limit is resolved automatically: `text-embedding-*` → 8191, `bge-m3` → 8192, `gemini-embedding-001` → 2048, other BGE models → 512, unknown models → 512.

# Limit truncation to 510 tokens to match a LocalAI batch_size=512 setup
EMBEDDING_MAX_TOKENS=510

Configuration Examples

Development Environment

# .env.development
NODE_ENV=development
PORT=3000

# Auth
JWT_SECRET=dev-secret-key

Production Environment

# .env.production
NODE_ENV=production
PORT=3000

# Security
JWT_SECRET=your-super-secure-production-secret

Docker Environment

# .env.docker
NODE_ENV=production
PORT=3000

# Security
JWT_SECRET_FILE=/run/secrets/jwt_secret

Environment Variable Loading

Pcnaid MCP Hub loads environment variables in the following order:

System environment variables
.env.local (ignored by git)
.env.{NODE_ENV} (e.g., .env.production)
.env

Using dotenv-expand

Pcnaid MCP Hub supports variable expansion:

BASE_URL=https://api.example.com
API_ENDPOINT=${BASE_URL}/v1

Security Best Practices

Never commit secrets to version control
Use strong, unique secrets for production
Rotate secrets regularly
Use environment-specific files
Validate all environment variables at startup
Use Docker secrets for container deployments

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Environment variables

Environment Variables

Core Application Settings

Server Configuration

Authentication & Security

Admin Password

JWT Configuration

Smart Routing & Embeddings

Embedding Configuration

Configuration Examples

Development Environment

Production Environment

Docker Environment

Environment Variable Loading

Using dotenv-expand

Security Best Practices

​Environment Variables

​Core Application Settings

​Server Configuration

​Authentication & Security

​Admin Password

​JWT Configuration

​Smart Routing & Embeddings

​Embedding Configuration

​Configuration Examples

​Development Environment

​Production Environment

​Docker Environment

​Environment Variable Loading

​Using dotenv-expand

​Security Best Practices

Environment Variables

Core Application Settings

Server Configuration

Authentication & Security

Admin Password

JWT Configuration

Smart Routing & Embeddings

Embedding Configuration

Configuration Examples

Development Environment

Production Environment

Docker Environment

Environment Variable Loading

Using dotenv-expand

Security Best Practices