v1.6.2

Enterprise

Maintenance Mode

Put your application into maintenance mode during deployments.

# Overview

CanxJS provides a simple way to put your application into maintenance mode. When in maintenance mode, all requests will receive a 503 (Service Unavailable) response with a customizable maintenance page.

# CLI Commands

Enable Maintenance Mode

# Basic usage

canx down

# With custom message

canx down --message="Upgrading to v2.0"

# With secret bypass

canx down --secret="my-secret-key"

# With retry header

canx down --retry=60

Disable Maintenance Mode

canx up

# Options

Option	Description
--message	Custom maintenance message
--secret	Secret key to bypass maintenance mode
--retry	Retry-After header value in seconds
--refresh	Auto-refresh interval in seconds
--redirect	Redirect to a custom URL
--except	URIs to bypass (comma-separated)

# Middleware

Add the maintenance middleware to check for maintenance mode in your application:

import { maintenanceMiddleware } from 'canxjs';

const app = createApp({
  middlewares: [
    maintenanceMiddleware({
      // Optional: Custom render function
      render: (req, data) => {
        return new Response('Custom maintenance page', { status: 503 });
      },
      // Optional: URIs to bypass
      except: ['/api/health', '/api/status'],
    }),
  ],
});

# Programmatic Usage

import { 
  maintenance, 
  isDownForMaintenance,
  preCheckMaintenance 
} from 'canxjs';

// Check if in maintenance mode
if (isDownForMaintenance()) {
  console.log('App is in maintenance mode');
}

// Get maintenance data
const data = maintenance().getData();
console.log(data?.message);

// Programmatically enable/disable
maintenance().activate({ message: 'Upgrading...' });
maintenance().deactivate();

// Pre-check (before app boots)
if (preCheckMaintenance()) {
  console.log('Skipping full app boot');
}

# Bypassing Maintenance Mode

When you set a secret key, you can bypass maintenance mode by adding a query parameter:

https://yoursite.com?_maintenance_secret=your-secret

After bypassing, a cookie will be set so you don't need to add the query parameter again.