Dogfooding Cloudflare Workers

What this post added

This post details the implementation of a Cloudflare Worker to intercept requests at the edge, inspect the TLS protocol version used by the client, and append a custom 'X-Client-SSL-Protocol' header to the request before forwarding it to the origin. This allows backend services to conditionally decorate responses with deprecation warnings and display banners in the dashboard. The worker was deployed to www.cloudflare.com and api.cloudflare.com, serving over 400 million requests. It also covers best practices for error handling (fail-open with `event.passThroughOnException()`) and asynchronous logging using `event.waitUntil()` with Sentry.