@thinkeloquent/core-no-cache

Fastify plugin for setting no-cache headers on all HTTP responses.

Features

• ✅ Sets no-cache headers on all responses globally
• ✅ Overrides any existing Cache-Control headers
• ✅ HTTP/1.0 compatibility with Pragma: no-cache
• ✅ Legacy client support with Expires: 0
• ✅ Configurable enable/disable option
• ✅ Type-safe with Zod validation
• ✅ Zero dependencies (except peer deps)
• ✅ Comprehensive test coverage

Headers Set

This plugin sets the following HTTP headers on every response:

• Cache-Control: no-cache, no-store, must-revalidate
• Pragma: no-cache
• Expires: 0

These headers ensure that browsers and proxies do not cache responses, always loading fresh content.

Installation

pnpm install @thinkeloquent/core-no-cache

Usage

Basic Usage

import Fastify from 'fastify';
import noCache from '@thinkeloquent/core-no-cache';

const server = Fastify();

// Register no-cache plugin
await server.register(noCache);

// All responses will now have no-cache headers
server.get('/api/data', async (request, reply) => {
  return { data: 'fresh data' };
});

await server.listen({ port: 3000 });

Configuration Options

import noCache from '@thinkeloquent/core-no-cache';

// Enable no-cache headers (default)
await server.register(noCache, {
  enabled: true,
});

// Disable no-cache headers
await server.register(noCache, {
  enabled: false,
});

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | enabled | boolean | true | Enable or disable no-cache headers |

When to Use

Development Mode

Perfect for development environments where you want to ensure:

• CSS and JavaScript changes are immediately visible
• No stale cached content
• Fresh API responses

SPA / Frontend Applications

Ideal for single-page applications (SPAs) where:

• You want to prevent HTML caching
• Assets are handled separately with specific cache policies
• You need fresh content on every navigation

API Servers

Great for API servers where:

• Data changes frequently
• Cache invalidation is complex
• You want guaranteed fresh responses

When NOT to Use

Production Static Assets

Don't use this plugin if you serve static assets (images, fonts, compiled JS/CSS) that should be cached for performance.

High-Traffic Production APIs

For production APIs with high traffic, consider:

• Implementing proper cache strategies (ETags, conditional requests)
• Using this plugin selectively on specific routes
• Implementing CDN-level caching

How It Works

The plugin uses Fastify's onSend hook to set headers on all responses:

1. Registers an onSend hook
2. For every response, sets the three no-cache headers
3. Overrides any existing Cache-Control headers set by routes

TypeScript Support

This plugin is written in TypeScript and provides full type definitions:

import type { NoCacheOptions, NoCacheResult } from '@thinkeloquent/core-no-cache';

Testing

Run tests:

pnpm test

Run tests with coverage:

pnpm run test:coverage

Development

Build the module:

pnpm run build

Type check:

pnpm run typecheck

License

MIT

Author

ThinkEloquent

Related Modules

• @thinkeloquent/core-route-logger - Log all routes
• @thinkeloquent/core-plugin-logger - Log all plugins
• @thinkeloquent/core-observability - Logging, tracing, and metrics