diff --git a/manyfold/CHANGELOG.md b/manyfold/CHANGELOG.md
index 85287fd717..5a8008ecf8 100644
--- a/manyfold/CHANGELOG.md
+++ b/manyfold/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.146.1-3 (2026-07-08)
+- Fix forced HTTPS redirect loop on the plain-HTTP UI by re-adding the `assume_ssl` disable workaround.
+- Export `PUBLIC_PORT` alongside `public_hostname` so generated links point at port 3214.
+- Document `public_hostname` in README (accepts hostname or server IP).
+
 ## 0.146.1-2 (06-07-2026)
 - Minor bugs fixed
  
diff --git a/manyfold/README.md b/manyfold/README.md
index 6876beaf44..3ffcab5581 100644
--- a/manyfold/README.md
+++ b/manyfold/README.md
@@ -53,6 +53,7 @@ Local development alternative on the HA host:
 ## Options
 
 - `secret_key_base`: App secret used by Rails to sign/encrypt sessions and tokens. See [Secret Key Base](#secret-key-base) below.
+- `public_hostname`: Hostname or server IP used to generate links (mailer and "Open in slicer" download URLs). Leave blank to auto-detect from Home Assistant's configured external URL, falling back to `homeassistant.local`.
 - `puid` / `pgid`: Ownership applied to writable mapped directories (`/config` paths).
 - `multiuser`: Toggle Manyfold multiuser mode.
 - `library_path`: Scanned/indexed path.
diff --git a/manyfold/config.yaml b/manyfold/config.yaml
index 7c9a236a24..e82953d4d9 100644
--- a/manyfold/config.yaml
+++ b/manyfold/config.yaml
@@ -1,7 +1,7 @@
 name: "Manyfold"
 slug: manyfold
 description: "Manyfold 3D model manager as a Home Assistant add-on, using the upstream image with configurable library/index paths."
-version: "0.146.1-2"
+version: "0.146.1-3"
 url: "https://github.com/alexbelgium/hassio-addons/tree/master/manyfold"
 image: ghcr.io/alexbelgium/manyfold-{arch}
 arch:
diff --git a/manyfold/run.sh b/manyfold/run.sh
index bb3bed5aad..c86336b5a9 100755
--- a/manyfold/run.sh
+++ b/manyfold/run.sh
@@ -153,16 +153,39 @@ generate_secret() {
   head -c 64 /dev/urandom | od -An -tx1 | tr -d ' \n'
 }
 
+# Manyfold's production.rb sets config.assume_ssl = PUBLIC_HOSTNAME.present?,
+# with no separate env var to opt out. assume_ssl makes Rails treat every
+# request as if it arrived over HTTPS (for a proxy that terminates SSL
+# upstream), which is wrong here: this add-on serves plain HTTP directly on
+# port 3214 with no TLS termination, so it produces bad https:// redirects
+# (e.g. to /users/sign_in) that browsers can't complete. Force it back off
+# via an initializer dropped into whichever app directory is found, since we
+# still need PUBLIC_HOSTNAME set for correct link generation elsewhere.
+disable_assume_ssl() {
+  local app_dir="$1"
+  local initializer_dir="${app_dir}/config/initializers"
+  [[ -d "$initializer_dir" ]] || return 0
+
+  cat > "${initializer_dir}/manyfold_addon_disable_assume_ssl.rb" << 'EOF'
+# Added by the Manyfold Home Assistant add-on: this add-on has no
+# SSL-terminating reverse proxy in front of it, so assuming SSL produces
+# incorrect https:// redirects on a plain-HTTP port.
+Rails.application.config.assume_ssl = false
+EOF
+}
+
 start_manyfold() {
   if [[ -x /usr/src/app/bin/docker-entrypoint.sh ]]; then
     log "Starting Manyfold via /usr/src/app/bin/docker-entrypoint.sh foreman start"
     cd /usr/src/app
+    disable_assume_ssl /usr/src/app
     exec ./bin/docker-entrypoint.sh foreman start
   fi
 
   if [[ -x /app/bin/docker-entrypoint.sh ]]; then
     log "Starting Manyfold via /app/bin/docker-entrypoint.sh foreman start"
     cd /app
+    disable_assume_ssl /app
     exec ./bin/docker-entrypoint.sh foreman start
   fi
 
@@ -189,8 +212,10 @@ start_manyfold() {
 
   if [[ -d /usr/src/app ]]; then
     cd /usr/src/app
+    disable_assume_ssl /usr/src/app
   elif [[ -d /app ]]; then
     cd /app
+    disable_assume_ssl /app
   fi
 
   if command -v bundle >/dev/null 2>&1; then
@@ -272,6 +297,7 @@ export MANYFOLD_MULTIUSER="$MULTIUSER"
 export MANYFOLD_LIBRARY_PATH="$LIBRARY_PATH"
 export MANYFOLD_THUMBNAILS_PATH="$THUMBNAILS_PATH"
 export PUBLIC_HOSTNAME
+export PUBLIC_PORT="3214"
 export RAILS_LOG_LEVEL="$LOG_LEVEL"
 export MANYFOLD_LOG_LEVEL="$LOG_LEVEL"
 export WEB_CONCURRENCY