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

# Compression

> Compress HTTP responses to reduce bandwidth using Apple's Compression framework.

# Compression Middleware

`PrismCompressionMiddleware` compresses response bodies using deflate compression — powered by Apple's native Compression framework. No zlib, no third-party libraries.

## Setup

```swift title="Enable Compression" theme={null}
await server.use(PrismCompressionMiddleware())
```

When a client sends `Accept-Encoding: deflate`, responses are automatically compressed. The middleware adds the `Content-Encoding: deflate` header.

## When to Use

Compression is most effective for:

* JSON API responses (typically 60-80% reduction)
* HTML pages
* Large text payloads

<Tip>
  Place compression middleware after caching middleware. You don't want to compress the same cached response on every request.
</Tip>

## Production Stack

```swift title="With Caching" theme={null}
await server.use(PrismResponseCacheMiddleware(ttl: 300)) // Cache first
await server.use(PrismCompressionMiddleware())            // Then compress
```

<Note>
  Small responses (under \~150 bytes) may actually get larger after compression overhead. The middleware handles this gracefully — it only compresses responses above a meaningful threshold.
</Note>