AFTER | commit e6b1b86786ed2d5d44f128e5adaf00b97af31260
Environment: Linux, Node v26.12.1, real Tailscale Serve, fresh isolated T3 home; no seeded data.
$ T3CODE_DEV_SEED=0 vp run dev --share --built --host localhost
Listening on http://[::1]:14870
$ tailscale serve status --json  # selected route; hostname redacted
https://<tailnet-host>:6830/ -> http://localhost:14870
$ ss -H -ltn (selected backend port)
LISTEN 0      511    [::1]:14870 [::]:*
$ curl --noproxy "*" -sS -o /dev/null -w "HTTP %{http_code}" http://127.0.0.1:14870/
HTTP 000; curl exit 7
curl: (7) Failed to connect to 127.0.0.1 port 14870 after 0 ms: Couldn't connect to server
$ curl --noproxy "*" -sS -o /dev/null -w "HTTP %{http_code}" http://[::1]:14870/
HTTP 302; curl exit 0
$ curl --noproxy "*" -sS -D headers -o body https://<tailnet-host>:6830/
HTTP/2 200 ; curl exit 0
Response body: HTML title: T3 Code (Beta)
$ curl --noproxy "*" -sS -D headers -o body https://<tailnet-host>:6830/pair
HTTP/2 200 ; curl exit 0
Response body: HTML title: T3 Code (Beta)