FrankenPHP: PHP App, Go Runtime

ATX Golang Meetup, September 2026

Slides at ian.im/fphpgo26

Ian Littman / @ian@phpc.social / @ian.im / @iansltx

Why am I up here?

• Did primarily Go dev for ~1.5 years at Fleet (2024-earlier this year)
• Have done PHP for a lot more of my career, since ~2012
• FrankenPHP bridges the two worlds

Aside: Longhorn PHP 2026 is in a little over a month (Oct 15+16) here in town
(mix of topics, mix/match days, no one submitted a Go for PHP devs talk this year)

What is it?

• Built on top of Caddy
• Replaces FastCGI PHP SAPI with one that plugs into net/http
  • NOT a PHP runtime reimpl (so NOT like goja)
  • No "two processes" 
• PHP app server, extensions in Go or C (plus Caddy modules)
• Default: shared-nothing, normal PHP execution
• Alternative: worker mode (load app once, requests flow through)
• Slower than FPM for shared-nothing, drastically faster in worker mode
• HTTP 103 Early Hints for pointing to scripts/styles that need loading later

Let's see some code

iansltx/weather-and-tolls

Heavily vibe-coded via Zed + GLM 5.3 Flash

Caveat: the Go ext builder can't throw exceptions

Thanks!

Slides at ian.im/fphpgo26

More info at frankenphp.dev

Questions? Find me here / @ian@phpc.social / @ian.im / @iansltx