> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pcnaid.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Environment variables

> Configure Pcnaid MCP Hub environment variables.

# 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`) |

```env theme={null}
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. |

```env theme={null}
ADMIN_PASSWORD=your-secure-admin-password
```

### JWT Configuration

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

```env theme={null}
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. |

```env theme={null}
# Limit truncation to 510 tokens to match a LocalAI batch_size=512 setup
EMBEDDING_MAX_TOKENS=510
```

## Configuration Examples

### Development Environment

```env theme={null}
# .env.development
NODE_ENV=development
PORT=3000

# Auth
JWT_SECRET=dev-secret-key
```

### Production Environment

```env theme={null}
# .env.production
NODE_ENV=production
PORT=3000

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

### Docker Environment

```env theme={null}
# .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:

1. System environment variables
2. `.env.local` (ignored by git)
3. `.env.{NODE_ENV}` (e.g., `.env.production`)
4. `.env`

### Using dotenv-expand

Pcnaid MCP Hub supports variable expansion:

```env theme={null}
BASE_URL=https://api.example.com
API_ENDPOINT=${BASE_URL}/v1
```

## Security Best Practices

1. **Never commit secrets** to version control
2. **Use strong, unique secrets** for production
3. **Rotate secrets regularly**
4. **Use environment-specific files**
5. **Validate all environment variables** at startup
6. **Use Docker secrets** for container deployments