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ETag Support

ETag Support in Solvix enables efficient caching and conditional requests by leveraging HTTP ETags.

It helps reduce unnecessary network calls and improves performance.

What is an ETag?​

An ETag (Entity Tag) is a unique identifier provided by the server for a specific resource version.

When the resource changes, the ETag changes.

Why ETag Support?​

In real-world systems:

  • Re-fetching unchanged data wastes bandwidth
  • APIs often support conditional requests
  • Performance can be improved significantly

ETag support allows Solvix to avoid unnecessary data transfers.

How it works​

  1. Server returns an ETag header
  2. Solvix stores the ETag
  3. Next request includes If-None-Match header
  4. Server responds:
    • 304 (Not Modified) → use cached data
    • 200 → update cache

Basic Usage​

const client = createClient({
  cache: {
    etag: true,
  },
});

Example Flow​

First request​

GET /users

Response:

ETag: "abc123"

Second request​

GET /users
If-None-Match: "abc123"

Server response​

304 Not Modified

Solvix will reuse cached response.

Benefits​

  • Reduced bandwidth usage
  • Faster response times
  • Lower server load

Use cases​

  • Frequently fetched data
  • Static resources
  • Dashboard APIs

Important Notes​

  • Requires server support for ETag
  • Cache must be enabled
  • Only works for idempotent requests (GET)

Best Practices​

  • Use with caching strategies
  • Combine with rate limiting
  • Avoid for highly dynamic data

Integration​

Works with:

  • Cache layer
  • Performance optimization
  • Network efficiency

Summary​

ETag Support improves performance by avoiding unnecessary data transfers and leveraging HTTP caching mechanisms.