Ports

Service	Port	Notes
Edge proxy (HTTP)	80	Caddy. Redirects to HTTPS
Edge proxy (HTTPS)	443	Caddy. TLS terminates here
Edge admin	unix socket	0600 in rexenv’s config dir — never a TCP port
Embedded DNS	15353 (UDP)	Answers *.rex and any other TLD you configure
Shared nginx	18088	One server block per site, behind the edge
php-fpm pools	9774, 9780–9785	One pool per installed PHP minor
php-fpm debug pools	9981–9985	Started on demand for Xdebug-toggled sites (8.1–8.5)
Xdebug DBGp	9003	Your IDE listens. rexenv binds nothing here
FrankenPHP overrides	8200–8299	Per site, loopback only
Apache overrides	8300–8399	Per site, loopback only
MySQL	13306
MariaDB	13307
PostgreSQL	15432
Redis	16379
Mailpit SMTP	11025
Mailpit web UI	18025
Adminer	no port	Served as an internal vhost through the shared nginx
cloudflared	no port	Outbound-only; nothing listens

Why the odd numbers

They are offset from the usual defaults on purpose. Mailpit’s stock ports are 1025 and 8025, MySQL’s is 3306 — using them would mean rexenv collides with a standalone Mailpit, a MailHog, another local environment, or a database you installed yourself.

The offsets are the difference between rexenv coexisting with your current setup and demanding you dismantle it first.

80 and 443 are the exception

Those cannot be offset. https://yoursite.rex with no port number means 443 — that is the whole point of the URL. If something else already holds them, rexenv names what is holding them instead of failing quietly, and rex doctor reports the same from a terminal.

The php-fpm pool numbering is not a range

Pool ports are computed as 9700 + major×10 + minor. That puts PHP 7.4 at 9774, below the 8.x block at 9780–9785, rather than at the start of a tidy contiguous range.

It is the formula being honest rather than the numbers being pretty: the port tells you which version is on the other end of it, and that stays true when a version is added or removed.

Xdebug listens on your side

9003 is the standard DBGp port and it is the only port in this table rexenv does not bind. PHP connects outward to your IDE, so your editor is the listener. That is why the Xdebug toggle needs no port configuration in rexenv — only in your IDE.

Every start is port-gated

Nothing starts without checking its port first. When one is taken, the message names the process holding it and gives a copy-pasteable way to deal with it, rather than reporting a generic failure to start.