diff --git a/README.md b/README.md
index 1730656..bc5af8c 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,7 @@ Update them any time with `sudo ./setup.sh configure`.
 |-------|---------|
 | `base` | `net-tools`, `ncdu`, `git`, `curl`, `wget`, `htop`, `tree`, `zip`/`unzip`, `ca-certificates`, `gnupg`, `jq`, `rsync`; `glow` (terminal markdown reader, Charm apt repo) |
 | `homelab` | `caddy`, `crowdsec`, `authelia`, `homeassistant`, `asterisk` |
-| `utilities` | `actualbudget`, `archivebox`, `changedetection`, `ddclient`, `filebrowser`, `fmd`, `gatus`, `homebox`, `joplin`, `magicmirror`, `mail-archiver`, `mattermost`, `mealie`, `meshcentral`, `n8n`, `nextcloud`, `ntfy`, `onlyoffice`, `portainer`, `rustdesk`, `stirling-pdf`, `syncthing`, `traccar`, `unifi`, `uptimekuma`, `vaultwarden`, `watchyourlan`, `watchtower`, `wg-easy` |
+| `utilities` | `actualbudget`, `archivebox`, `changedetection`, `ddclient`, `filebrowser`, `fmd`, `gatus`, `homebox`, `joplin`, `koha`, `magicmirror`, `mail-archiver`, `mattermost`, `mealie`, `meshcentral`, `n8n`, `nextcloud`, `ntfy`, `onlyoffice`, `portainer`, `rustdesk`, `stirling-pdf`, `syncthing`, `traccar`, `unifi`, `uptimekuma`, `vaultwarden`, `watchyourlan`, `watchtower`, `wg-easy` |
 | `media` | `arm`, `audiobookshelf`, `calibre-web`, `emby`, `immich`, `jellyfin`, `lyrion` |
 | `cameras` | `frigate`, `frigate-audio`, `frigate-notify`, `sky-cam` |
 | `gaming` | `drum-rhythm-game`, `js99er`, `minecraft`, `wolf`, `wolf-pair` |
diff --git a/services/koha.sh b/services/koha.sh
new file mode 100644
index 0000000..4915a10
--- /dev/null
+++ b/services/koha.sh
@@ -0,0 +1,386 @@
+#!/bin/bash
+# services/koha.sh — Koha Integrated Library System (physical book catalog + loans).
+# Part of the modular post-install system (sourced by setup.sh).
+#
+# Can also be run standalone on any machine:
+#   sudo bash koha.sh
+# (Docker must already be installed when run standalone)
+#
+# Uses teogramm/koha (single bundled container: Apache, Plack, Zebra indexer,
+# background jobs worker) + MariaDB + Memcached + RabbitMQ sidecars.
+# OPAC (patron UI): port 8097  |  Staff/admin: port 8098
+# RAM: needs ~2.5 GB free.
+
+# ── Standalone bootstrap ──────────────────────────────────────────────────────
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+    [[ "$(id -u)" == "0" ]] || { echo "Run with sudo: sudo bash $0"; exit 1; }
+
+    _SELF_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+    _COMMON="$_SELF_DIR/../lib/common.sh"
+
+    if [[ -f "$_COMMON" ]]; then
+        source "$_COMMON"
+    else
+        log_info()    { echo -e "\033[0;34m[INFO]\033[0m $*"; }
+        log_success() { echo -e "\033[0;32m[OK]\033[0m $*"; }
+        log_warning() { echo -e "\033[1;33m[WARN]\033[0m $*"; }
+        log_error()   { echo -e "\033[0;31m[ERROR]\033[0m $*" >&2; }
+
+        require_docker() {
+            command -v docker &>/dev/null || {
+                log_error "Docker not found. Install it first:"
+                log_error "  curl -fsSL https://get.docker.com | sudo sh"
+                return 1
+            }
+            docker compose version &>/dev/null || {
+                log_error "Docker Compose plugin missing:"
+                log_error "  sudo apt-get install -y docker-compose-plugin"
+                return 1
+            }
+        }
+
+        ensure_docker_dir_ownership() {
+            chown -R "$ACTUAL_USER:$ACTUAL_USER" "$@" 2>/dev/null || true
+        }
+
+        generate_password() {
+            local _len="${1:-32}"
+            tr -dc 'A-Za-z0-9' < /dev/urandom | head -c "$_len"
+            echo
+        }
+
+        prompt_text() {
+            local _q="$1" _def="$2" _var="$3" _r
+            [[ "${UNATTENDED:-false}" == "true" ]] && { eval "$_var='$_def'"; return; }
+            read -r -p "  $_q " _r
+            eval "$_var='${_r:-$_def}'"
+        }
+
+        prompt_yn() {
+            local _q="$1" _def="$2" _var="$3" _r
+            [[ "${UNATTENDED:-false}" == "true" ]] && { eval "$_var='$_def'"; return; }
+            read -r -p "  $_q " _r
+            eval "$_var='${_r:-$_def}'"
+        }
+
+        configure_caddy_for_service() {
+            local _name="$1" _upstream="$2" _subdomain="$3" _extra="${4:-}"
+            local _caddy_dir="$DOCKER_DIR/caddy"
+            local _caddyfile="$_caddy_dir/Caddyfile"
+            local _display_port="${_upstream##*:}"
+
+            local _mode="none"
+            [[ -d "$_caddy_dir" ]] && _mode="local"
+            [[ -n "${CADDY_REMOTE_HOST:-}" ]] && [[ "$_mode" != "local" ]] && _mode="remote"
+            [[ "$_mode" == "none" ]] && {
+                log_info "Access $_name directly on port $_display_port."
+                return 0
+            }
+
+            echo ""
+            local _do_caddy=""
+            if [[ "$_mode" == "remote" ]]; then
+                log_info "Remote Caddy configured (${CADDY_REMOTE_HOST})."
+                log_info "A snippet file will be saved to ~/docker/caddy-snippets/."
+            fi
+            read -r -p "  Configure Caddy reverse proxy for $_name? [y/N]: " _do_caddy
+            [[ "${_do_caddy,,}" == "y" ]] || {
+                log_info "Skipping — access at: http://localhost:$_display_port"
+                return 0
+            }
+
+            local _default_domain=""
+            if [[ -n "${SITE_DOMAIN:-}" ]] && [[ "$SITE_DOMAIN" != "example.com" ]]; then
+                _default_domain="${_subdomain}.${SITE_DOMAIN}"
+                log_info "Default: $_default_domain"
+            fi
+            local _domain=""
+            read -r -p "  Domain [${_default_domain:-required}]: " _domain
+            _domain="${_domain:-$_default_domain}"
+            [[ -n "$_domain" ]] || { log_warning "No domain entered — skipping Caddy."; return 0; }
+
+            local _block_upstream="$_upstream"
+            if [[ "$_mode" == "remote" ]]; then
+                _block_upstream="${CADDY_REMOTE_HOST}:${_display_port}"
+            fi
+
+            local _site_block
+            _site_block="$(cat << CBLOCK
+
+# $_name
+${_domain} {
+    reverse_proxy ${_block_upstream}
+
+    header {
+        Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
+        X-Content-Type-Options "nosniff"
+        X-Frame-Options "SAMEORIGIN"
+        Referrer-Policy "strict-origin-when-cross-origin"
+    }
+
+    log {
+        output file /var/log/caddy/${_domain}.log
+        format json
+    }
+${_extra}
+}
+CBLOCK
+)"
+
+            if [[ "$_mode" == "local" ]]; then
+                if [[ -f "$_caddyfile" ]]; then
+                    local _bk="$_caddy_dir/Caddyfile.backup.$(date +%Y%m%d-%H%M%S)"
+                    cp "$_caddyfile" "$_bk"
+                    log_info "Backed up Caddyfile to $(basename "$_bk")"
+                else
+                    touch "$_caddyfile"
+                fi
+
+                if grep -q "^${_domain}" "$_caddyfile" 2>/dev/null; then
+                    log_warning "$_domain already in Caddyfile"
+                    local _ow=""
+                    read -r -p "  Overwrite? [y/N]: " _ow
+                    [[ "${_ow,,}" == "y" ]] || { log_info "Keeping existing entry."; return 0; }
+                    sed -i "/^${_domain}/,/^}/d" "$_caddyfile"
+                fi
+
+                printf '%s\n' "$_site_block" >> "$_caddyfile"
+                log_success "Added $_domain to Caddyfile"
+                docker exec caddy caddy fmt --overwrite /etc/caddy/Caddyfile 2>/dev/null || true
+                if docker exec caddy caddy reload --config /etc/caddy/Caddyfile 2>/dev/null; then
+                    log_success "$_name accessible at: https://$_domain"
+                else
+                    log_warning "Reload failed — check: docker logs caddy"
+                    log_info "Manual reload: docker exec caddy caddy reload --config /etc/caddy/Caddyfile"
+                fi
+            else
+                local _snippet_dir="$DOCKER_DIR/caddy-snippets"
+                local _snippet_file="$_snippet_dir/${_subdomain}.caddy"
+                mkdir -p "$_snippet_dir"
+                printf '%s\n' "$_site_block" > "$_snippet_file"
+                chown "$ACTUAL_USER:$ACTUAL_USER" "$_snippet_file" 2>/dev/null || true
+                log_success "Snippet saved: $_snippet_file"
+                log_info "Copy to Caddy machine:"
+                log_info "  scp $_snippet_file caddy-host:~/caddy-snippets/"
+                log_info "  rsync -av $_snippet_dir/ caddy-host:~/caddy-snippets/  (all at once)"
+            fi
+        }
+        write_readme() {
+            local _dir="$1"; shift
+            mkdir -p "$_dir"
+            cat > "$_dir/README.md"
+        }
+    fi
+
+    ACTUAL_USER="${ACTUAL_USER:-${SUDO_USER:-$USER}}"
+    ACTUAL_HOME="$(getent passwd "$ACTUAL_USER" 2>/dev/null | cut -d: -f6 || echo "${HOME:-/root}")"
+    DOCKER_DIR="${DOCKER_DIR:-$ACTUAL_HOME/docker}"
+    DRY_RUN="${DRY_RUN:-false}"
+    UNATTENDED="${UNATTENDED:-false}"
+    SITE_TZ="${SITE_TZ:-$(cat /etc/timezone 2>/dev/null || echo UTC)}"
+    SITE_DOMAIN="${SITE_DOMAIN:-example.com}"
+    SITE_CADDY_NET="${SITE_CADDY_NET:-caddy_net}"
+    CADDY_REMOTE_HOST="${CADDY_REMOTE_HOST:-}"
+
+    register_service() { :; }
+    _RUN_STANDALONE=1
+fi
+# ─────────────────────────────────────────────────────────────────────────────
+
+register_service koha utilities "Physical book library — catalog, shelf locations, loans/checkout (Koha ILS)" 8097
+
+install_koha() {
+    require_docker || return 1
+
+    local KOHA_DIR="$DOCKER_DIR/koha"
+
+    if [ "$DRY_RUN" = true ]; then
+        echo "[DRY-RUN] koha would:"
+        echo "  - Create $KOHA_DIR with docker-compose.yml + config-main.env"
+        echo "  - Deploy teogramm/koha + MariaDB + Memcached + RabbitMQ"
+        echo "  - OPAC (patron UI):   port 8097"
+        echo "  - Staff/admin:        port 8098"
+        echo "  - Requires ~2.5 GB free RAM"
+        return 0
+    fi
+
+    echo ""
+    echo "  Koha is a full Integrated Library System (ILS):"
+    echo "  • ISBN barcode scanning → auto-fetch cover art, author, summary"
+    echo "  • Shelf / location tracking (define your own locations)"
+    echo "  • Loan / checkout system with due dates and history"
+    echo "  • OPAC (patron browsing UI) + staff admin interface"
+    echo "  • Requires ~2.5 GB free RAM (4 containers: Koha, MariaDB, Memcached, RabbitMQ)"
+    echo ""
+
+    local DB_PASS RABBIT_PASS
+    DB_PASS=$(generate_password 24)
+    RABBIT_PASS=$(generate_password 24)
+
+    mkdir -p "$KOHA_DIR"
+    ensure_docker_dir_ownership "$KOHA_DIR"
+    cd "$KOHA_DIR" || return 1
+
+    cat > docker-compose.yml << 'KOHA_COMPOSE'
+name: koha
+
+services:
+  koha:
+    image: teogramm/koha:24.11
+    container_name: koha
+    hostname: koha
+    restart: unless-stopped
+    cap_add:
+      - DAC_READ_SEARCH
+      - SYS_NICE
+    env_file:
+      - config-main.env
+    ports:
+      - "8097:8080"
+      - "8098:8081"
+    depends_on:
+      - koha-db
+      - koha-memcached
+      - koha-rabbitmq
+    networks:
+      - koha_internal
+      - caddy_net
+
+  koha-db:
+    image: mariadb:11
+    container_name: koha-db
+    hostname: koha-db
+    restart: unless-stopped
+    environment:
+      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASS}
+      MYSQL_DATABASE: koha_default
+      MYSQL_USER: koha_default
+      MYSQL_PASSWORD: ${DB_PASS}
+    volumes:
+      - koha_db_data:/var/lib/mysql
+    networks:
+      - koha_internal
+
+  koha-memcached:
+    image: memcached:latest
+    container_name: koha-memcached
+    hostname: koha-memcached
+    restart: unless-stopped
+    networks:
+      - koha_internal
+
+  koha-rabbitmq:
+    image: rabbitmq:3
+    container_name: koha-rabbitmq
+    hostname: koha-rabbitmq
+    restart: unless-stopped
+    environment:
+      RABBITMQ_DEFAULT_USER: koha
+      RABBITMQ_DEFAULT_PASS: ${RABBIT_PASS}
+    networks:
+      - koha_internal
+
+volumes:
+  koha_db_data:
+
+networks:
+  koha_internal:
+    internal: true
+  caddy_net:
+    external: true
+    name: ${CADDY_NET:-caddy_net}
+KOHA_COMPOSE
+
+    cat > config-main.env << KOHA_ENV
+# Koha ILS configuration — generated at install time
+MYSQL_SERVER=koha-db
+DB_NAME=koha_default
+MYSQL_USER=koha_default
+MYSQL_PASSWORD=$DB_PASS
+DB_ROOT_PASS=$(generate_password 24)
+MEMCACHED_SERVERS=koha-memcached:11211
+MB_HOST=koha-rabbitmq
+MB_PORT=61613
+MB_USER=koha
+MB_PASS=$RABBIT_PASS
+RABBIT_PASS=$RABBIT_PASS
+DB_PASS=$DB_PASS
+CADDY_NET=$SITE_CADDY_NET
+KOHA_LANGS=en
+ZEBRA_MARC_FORMAT=marc21
+USE_Z3950=1
+KOHA_ENV
+
+    chmod 600 config-main.env
+    ensure_docker_dir_ownership "$KOHA_DIR"
+    log_success "Koha configured at $KOHA_DIR"
+
+    # Koha has its own staff login — no Authelia for staff interface
+    # OPAC is public-facing, Caddy proxies to OPAC port
+    configure_caddy_for_service "Koha OPAC" "koha:8080" "library"
+
+    write_readme "$KOHA_DIR" << MD
+# Koha ILS — Home Library
+
+Full Integrated Library System for managing a physical book collection.
+
+## Access
+- **OPAC** (patron browsing): http://localhost:8097
+- **Staff / admin**:          http://localhost:8098
+
+## First-time setup (important — takes ~5 minutes)
+1. Open the **staff interface**: http://localhost:8098
+2. Wait for the setup wizard (Koha takes 2–3 minutes to initialize on first start)
+3. Follow the web installer — it asks for library name, MARC flavour (choose MARC21),
+   and creates your admin account
+4. Go to Administration → Basic parameters → Libraries to add your library
+5. Go to Administration → Basic parameters → Item types to define your book categories
+6. Go to Administration → Basic parameters → Authorized values → LOC to define
+   shelf locations (e.g. "LR1" = Living Room Shelf 1)
+
+## Adding books
+- **By ISBN** (recommended): Cataloguing → Z39.50/SRU search → enter ISBN →
+  imports full metadata, cover art, summary from WorldCat/OpenLibrary
+- **Barcode scanning**: use any USB barcode scanner or phone camera app;
+  scan ISBN on the back of the book
+
+## Loans / checkout
+- Patron management: Patrons → New patron (add family members)
+- Checkout: Circulation → Check out → scan patron card, scan book barcode
+- Return: Circulation → Check in
+
+## Manage
+\`\`\`bash
+cd $KOHA_DIR
+docker compose up -d      # start (allow 3 min for first-time init)
+docker compose down       # stop
+docker compose logs -f    # logs
+docker compose pull && docker compose up -d   # update
+\`\`\`
+
+## Shelf locations
+Define custom locations in Staff → Administration → Authorized values → LOST
+(or create a new category). Common home library codes:
+- LR1, LR2 — Living Room shelves
+- BR — Bedroom
+- OF — Office
+- BS — Basement
+MD
+
+    local START_KOHA=""
+    prompt_yn "Start Koha now? (y/n):" "y" START_KOHA
+    if [ "$START_KOHA" = "y" ] || [ "$START_KOHA" = "Y" ]; then
+        docker compose up -d \
+            && log_success "Koha starting (takes 2–3 min on first run)" \
+            || log_warning "Start failed — check: docker compose logs koha"
+    fi
+
+    echo ""
+    echo "  OPAC (patron UI): http://localhost:8097"
+    echo "  Staff / admin:    http://localhost:8098"
+    echo "  First run: open staff interface and complete the setup wizard (~5 min)"
+    echo "  Credentials saved in: $KOHA_DIR/config-main.env"
+    echo ""
+}
+
+[[ "${_RUN_STANDALONE:-0}" == 1 ]] && install_koha