diff --git a/.env.template b/.env.template
index 422758d..d563dcb 100644
--- a/.env.template
+++ b/.env.template
@@ -42,6 +42,10 @@ REPLICATION_BACKEND_PUBLIC_KEY=
 # random secret used for token encryption (replication-backend)
 REPLICATION_BACKEND_JWT_SECRET=
 
+# Keycloak service account for replication-backend permission checks
+REPLICATION_BACKEND_KEYCLOAK_CLIENT_ID=aam-backend
+REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET=
+
 # Sentry configuration (app, replication-backend and aam-backend)
 SENTRY_DSN=
 SENTRY_DSN_REPLICATION_BACKEND=
diff --git a/docker-compose.yml b/docker-compose.yml
index 4aad234..80c094f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -66,6 +66,10 @@ services:
       SENTRY_ENABLED: ${SENTRY_ENABLED}
       SENTRY_INSTANCE_NAME: ${INSTANCE_NAME}.${INSTANCE_DOMAIN}
       SENTRY_ENVIRONMENT: ${SENTRY_ENVIRONMENT}
+      KEYCLOAK_ADMIN_BASE_URL: https://${KEYCLOAK_URL}
+      KEYCLOAK_REALM: ${INSTANCE_NAME}
+      KEYCLOAK_ADMIN_CLIENT_ID: ${REPLICATION_BACKEND_KEYCLOAK_CLIENT_ID:-aam-backend}
+      KEYCLOAK_ADMIN_CLIENT_SECRET: ${REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET}
       PORT: 5984
     restart: unless-stopped
     profiles:
@@ -81,6 +85,7 @@ services:
       - external_web
     depends_on:
       - couchdb-with-permissions
+      - replication-backend
       - aam-backend-service-db
       - rabbitmq
     volumes:
diff --git a/scripts/enable-backend.sh b/scripts/enable-backend.sh
index d3273e4..5cd02ab 100755
--- a/scripts/enable-backend.sh
+++ b/scripts/enable-backend.sh
@@ -51,6 +51,9 @@ RENDER_API_CLIENT_ID_DEV=$(bws secret -t "$BWS_ACCESS_TOKEN" get "b53d7a1d-220e-
 RENDER_API_CLIENT_SECRET_DEV=$(bws secret -t "$BWS_ACCESS_TOKEN" get "83a8e38b-fc22-461f-91a0-b22700712b62" | jq -r .value)
 SENTRY_AUTH_TOKEN=$(bws secret -t "$BWS_ACCESS_TOKEN" get "b9a3e1eb-3925-4ed6-93f4-b2270073c82c" | jq -r .value)
 SENTRY_DSN_BACKEND=$(bws secret -t "$BWS_ACCESS_TOKEN" get "a858a580-9643-4330-8667-b2270073d7a6" | jq -r .value)
+KEYCLOAK_HOST=$(bws secret -t "$BWS_ACCESS_TOKEN" get "3db87144-76c9-4690-8f59-b22600c8c927" | jq -r .value)
+KEYCLOAK_PASSWORD=$(bws secret -t "$BWS_ACCESS_TOKEN" get "c5f42f09-b1c8-43a8-ae75-b22600c8f2e5" | jq -r .value)
+KEYCLOAK_USER=$(bws secret -t "$BWS_ACCESS_TOKEN" get "fbe4ba07-538d-49e2-92dd-b22600c8d9d2" | jq -r .value)
 
 chars=abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
 
@@ -101,9 +104,12 @@ setEnv() {
     local key="$1"
     local value="$2"
     local path="$3"
+    # escape sed special characters in value (\, &, |)
+    local escaped
+    escaped=$(printf '%s' "$value" | sed 's/[\\&|]/\\&/g')
 
-    sed -i "s|^$key=.*|$key=$value|g" "$path" # linux
-    # gsed -i "s|^$key=.*|$key=$value|g" "$path" # macos
+    sed -i "s|^$key=.*|$key=$escaped|g" "$path" # linux
+    # gsed -i "s|^$key=.*|$key=$escaped|g" "$path" # macos
 }
 
 # Funktion zum Abrufen der Umgebungsvariablen
@@ -130,6 +136,107 @@ generate_password() {
   done
 }
 
+getKeycloakToken() {
+  token=$(curl -s -L "https://$KEYCLOAK_HOST/realms/master/protocol/openid-connect/token" -H 'Content-Type: application/x-www-form-urlencoded' --data-urlencode username="$KEYCLOAK_USER" --data-urlencode password="$KEYCLOAK_PASSWORD" --data-urlencode grant_type=password --data-urlencode client_id=admin-cli)
+  token=${token#*\"access_token\":\"}
+  token=${token%%\"*}
+}
+
+createKeycloakBackendClient() {
+  local realm="$1"
+  clientSecret=""
+
+  getKeycloakToken
+
+  # check if aam-backend client already exists (idempotent)
+  local existing
+  existing=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients?clientId=aam-backend" \
+    -H "Authorization: Bearer $token")
+  clientUuid=$(echo "$existing" | jq -r '.[0].id // empty')
+
+  if [ -z "$clientUuid" ]; then
+    # create the aam-backend client (confidential, service account enabled)
+    clientResponse=$(curl -s -D - -o /dev/null -X POST "https://$KEYCLOAK_HOST/admin/realms/$realm/clients" \
+      -H "Authorization: Bearer $token" \
+      -H "Content-Type: application/json" \
+      -d '{
+        "clientId": "aam-backend",
+        "enabled": true,
+        "clientAuthenticatorType": "client-secret",
+        "serviceAccountsEnabled": true,
+        "publicClient": false,
+        "standardFlowEnabled": false,
+        "directAccessGrantsEnabled": false,
+        "protocol": "openid-connect"
+      }')
+
+    # extract client UUID from Location header
+    location=$(echo "$clientResponse" | grep -i "^location:")
+    clientUuid=$(echo "$location" | sed -n 's#.*\([a-f0-9]\{8\}-[a-f0-9]\{4\}-[a-f0-9]\{4\}-[a-f0-9]\{4\}-[a-f0-9]\{12\}\).*#\1#p')
+
+    if [ -z "$clientUuid" ]; then
+      echo "ERROR: Failed to create aam-backend client in Keycloak realm '$realm'."
+      return 1
+    fi
+
+    echo "Created aam-backend client: $clientUuid"
+  else
+    echo "aam-backend client already exists: $clientUuid"
+  fi
+
+  # get client secret
+  clientSecret=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$clientUuid/client-secret" \
+    -H "Authorization: Bearer $token" | jq -r '.value // empty')
+
+  if [ -z "$clientSecret" ]; then
+    echo "ERROR: Failed to retrieve client secret for aam-backend client in realm '$realm'."
+    return 1
+  fi
+
+  # get the service account user
+  serviceAccountUserId=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$clientUuid/service-account-user" \
+    -H "Authorization: Bearer $token" | jq -r '.id // empty')
+
+  if [ -z "$serviceAccountUserId" ]; then
+    echo "ERROR: Failed to retrieve service account user for aam-backend client in realm '$realm'."
+    return 1
+  fi
+
+  # get the realm-management client UUID
+  realmMgmtClientUuid=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients?clientId=realm-management" \
+    -H "Authorization: Bearer $token" | jq -r '.[0].id // empty')
+
+  if [ -z "$realmMgmtClientUuid" ]; then
+    echo "ERROR: Failed to retrieve realm-management client in realm '$realm'."
+    return 1
+  fi
+
+  # get the manage-realm role from realm-management client
+  manageRealmRole=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$realmMgmtClientUuid/roles/manage-realm" \
+    -H "Authorization: Bearer $token")
+
+  # assign manage-realm role to the service account
+  curl -s -X POST "https://$KEYCLOAK_HOST/admin/realms/$realm/users/$serviceAccountUserId/role-mappings/clients/$realmMgmtClientUuid" \
+    -H "Authorization: Bearer $token" \
+    -H "Content-Type: application/json" \
+    -d "[$manageRealmRole]"
+
+  echo "Assigned manage-realm role to aam-backend service account."
+
+  # ensure the "roles" client scope is assigned (required for role claims in the access token)
+  local rolesScopeUuid
+  rolesScopeUuid=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/client-scopes" \
+    -H "Authorization: Bearer $token" | jq -r '.[] | select(.name == "roles") | .id // empty')
+
+  if [ -n "$rolesScopeUuid" ]; then
+    curl -s -X PUT "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$clientUuid/default-client-scopes/$rolesScopeUuid" \
+      -H "Authorization: Bearer $token"
+    echo "Ensured 'roles' client scope on aam-backend client."
+  else
+    echo "WARNING: Could not find 'roles' client scope in realm '$realm'."
+  fi
+}
+
 ##############################
 # script
 ##############################
@@ -182,6 +289,9 @@ setEnv CRYPTO_CONFIGURATION_SECRET "$password" "$path/config/aam-backend-service
 setEnv SPRING_SECURITY_OAUTH2_RESOURCESERVER_JWT_ISSUERURI "https://keycloak.aam-digital.com/realms/$instance" "$path/config/aam-backend-service/application.env"
 setEnv SPRING_DATASOURCE_USERNAME "$(getVar "$path/.env" COUCHDB_USER)" "$path/config/aam-backend-service/application.env"
 setEnv SPRING_DATASOURCE_PASSWORD "$(getVar "$path/.env" COUCHDB_PASSWORD)" "$path/config/aam-backend-service/application.env"
+setEnv AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASEPATH "http://replication-backend:5984" "$path/config/aam-backend-service/application.env"
+setEnv AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASICAUTHUSERNAME "$(getVar "$path/.env" COUCHDB_USER)" "$path/config/aam-backend-service/application.env"
+setEnv AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASICAUTHPASSWORD "$(getVar "$path/.env" COUCHDB_PASSWORD)" "$path/config/aam-backend-service/application.env"
 setEnv COUCHDBCLIENTCONFIGURATION_BASICAUTHUSERNAME "$(getVar "$path/.env" COUCHDB_USER)" "$path/config/aam-backend-service/application.env"
 setEnv COUCHDBCLIENTCONFIGURATION_BASICAUTHPASSWORD "$(getVar "$path/.env" COUCHDB_PASSWORD)" "$path/config/aam-backend-service/application.env"
 setEnv SQSCLIENTCONFIGURATION_BASICAUTHUSERNAME "$(getVar "$path/.env" COUCHDB_USER)" "$path/config/aam-backend-service/application.env"
@@ -195,6 +305,22 @@ setEnv SENTRY_AUTH_TOKEN "$SENTRY_AUTH_TOKEN" "$path/config/aam-backend-service/
 setEnv SENTRY_DSN "$SENTRY_DSN_BACKEND" "$path/config/aam-backend-service/application.env"
 setEnv SENTRY_SERVER_NAME "$instance.$DOMAIN" "$path/config/aam-backend-service/application.env"
 
+# create aam-backend Keycloak client for permission checks
+if ! createKeycloakBackendClient "$instance"; then
+  echo "ERROR: Failed to create/get Keycloak backend client for '$instance'. Aborting."
+  exit 1
+fi
+if [ -z "$clientSecret" ]; then
+  echo "ERROR: Keycloak client created but secret could not be retrieved for '$instance'. Aborting."
+  exit 1
+fi
+
+# ensure key exists before setting (older .env templates may lack it)
+if ! grep -q '^REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET=' "$path/.env"; then
+  echo "REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET=" >> "$path/.env"
+fi
+setEnv REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET "$clientSecret" "$path/.env"
+
 setEnv COMPOSE_PROFILES "full-stack" "$path/.env"
 
 (cd "$path" && docker compose up -d)
diff --git a/scripts/migrate-permission-check.sh b/scripts/migrate-permission-check.sh
new file mode 100755
index 0000000..d31a4d8
--- /dev/null
+++ b/scripts/migrate-permission-check.sh
@@ -0,0 +1,299 @@
+#!/bin/bash
+
+# Migration script: adds Keycloak service account for replication-backend permission checks.
+#
+# For each instance:
+# - Adds REPLICATION_BACKEND_KEYCLOAK_CLIENT_ID / SECRET to .env
+# - For full-stack instances: creates the aam-backend Keycloak client with manage-realm role
+# - For full-stack instances: ensures AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASICAUTH* vars exist in application.env
+#
+# Usage:
+#   ./migrate-permission-check.sh                # migrate all instances
+#   ./migrate-permission-check.sh <instance>      # migrate single instance
+#
+# Requires: BWS_ACCESS_TOKEN set in environment or setup.env
+
+set -uo pipefail
+
+baseDirectory="/var/docker"
+source "$baseDirectory/ndb-setup/setup.env"
+
+##############################
+# BWS secrets
+##############################
+
+if [[ -z "${BWS_ACCESS_TOKEN:-}" ]]; then
+  echo "BWS_ACCESS_TOKEN is not set. Abort."
+  exit 1
+fi
+
+bws config server-base https://vault.bitwarden.eu
+
+KEYCLOAK_HOST=$(bws secret -t "$BWS_ACCESS_TOKEN" get "3db87144-76c9-4690-8f59-b22600c8c927" | jq -r .value)
+KEYCLOAK_PASSWORD=$(bws secret -t "$BWS_ACCESS_TOKEN" get "c5f42f09-b1c8-43a8-ae75-b22600c8f2e5" | jq -r .value)
+KEYCLOAK_USER=$(bws secret -t "$BWS_ACCESS_TOKEN" get "fbe4ba07-538d-49e2-92dd-b22600c8d9d2" | jq -r .value)
+
+##############################
+# helpers
+##############################
+
+getVar() {
+  local file="$1"
+  local var="$2"
+  grep "^$var=" "$file" 2>/dev/null | cut -d '=' -f2- || echo ""
+}
+
+setEnv() {
+  local key="$1"
+  local value="$2"
+  local file="$3"
+  # escape sed special characters in value (\, &, |)
+  local escaped
+  escaped=$(printf '%s' "$value" | sed 's/[\\&|]/\\&/g')
+  sed -i "s|^$key=.*|$key=$escaped|g" "$file"
+}
+
+# Create a timestamped backup of a file
+backupFile() {
+  local file="$1"
+  local backup="$file.bak-$(date +%Y%m%d%H%M%S)"
+  if [ -f "$file" ]; then
+    cp "$file" "$backup"
+    echo "  backup: $(basename "$backup")"
+  fi
+}
+
+# Append a variable to a file if it does not already exist
+ensureEnv() {
+  local key="$1"
+  local value="$2"
+  local file="$3"
+  if ! grep -q "^$key=" "$file" 2>/dev/null; then
+    echo "$key=$value" >> "$file"
+    echo "  + added $key to $(basename "$file")"
+  fi
+}
+
+getKeycloakToken() {
+  local raw
+  raw=$(curl -s -L "https://$KEYCLOAK_HOST/realms/master/protocol/openid-connect/token" \
+    -H 'Content-Type: application/x-www-form-urlencoded' \
+    --data-urlencode username="$KEYCLOAK_USER" \
+    --data-urlencode password="$KEYCLOAK_PASSWORD" \
+    --data-urlencode grant_type=password \
+    --data-urlencode client_id=admin-cli)
+  token=${raw#*\"access_token\":\"}
+  token=${token%%\"*}
+
+  if [ -z "$token" ] || [ "$token" = "$raw" ]; then
+    echo "  ERROR: Failed to get Keycloak admin token."
+    return 1
+  fi
+}
+
+# Creates the aam-backend Keycloak client (if it doesn't exist) and assigns manage-realm role.
+# Sets $clientSecret on success.
+createOrGetKeycloakBackendClient() {
+  local realm="$1"
+  clientSecret=""
+
+  getKeycloakToken
+
+  # check if aam-backend client already exists
+  local existing
+  existing=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients?clientId=aam-backend" \
+    -H "Authorization: Bearer $token")
+  local existingUuid
+  existingUuid=$(echo "$existing" | jq -r '.[0].id // empty')
+
+  if [ -n "$existingUuid" ]; then
+    echo "  aam-backend client already exists: $existingUuid"
+    clientSecret=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$existingUuid/client-secret" \
+      -H "Authorization: Bearer $token" | jq -r '.value // empty')
+
+    # ensure service account has manage-realm role (idempotent)
+    assignManageRealmRole "$realm" "$existingUuid"
+    return 0
+  fi
+
+  # create the aam-backend client (confidential, service account enabled)
+  local clientResponse
+  clientResponse=$(curl -s -D - -o /dev/null -X POST "https://$KEYCLOAK_HOST/admin/realms/$realm/clients" \
+    -H "Authorization: Bearer $token" \
+    -H "Content-Type: application/json" \
+    -d '{
+      "clientId": "aam-backend",
+      "enabled": true,
+      "clientAuthenticatorType": "client-secret",
+      "serviceAccountsEnabled": true,
+      "publicClient": false,
+      "standardFlowEnabled": false,
+      "directAccessGrantsEnabled": false,
+      "protocol": "openid-connect"
+    }')
+
+  local location clientUuid
+  location=$(echo "$clientResponse" | grep -i "^location:")
+  clientUuid=$(echo "$location" | sed -n 's#.*\([a-f0-9]\{8\}-[a-f0-9]\{4\}-[a-f0-9]\{4\}-[a-f0-9]\{4\}-[a-f0-9]\{12\}\).*#\1#p')
+
+  if [ -z "$clientUuid" ]; then
+    echo "  ERROR: Failed to create aam-backend client in realm '$realm'."
+    return 1
+  fi
+
+  echo "  Created aam-backend client: $clientUuid"
+
+  clientSecret=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$clientUuid/client-secret" \
+    -H "Authorization: Bearer $token" | jq -r '.value // empty')
+
+  assignManageRealmRole "$realm" "$clientUuid"
+}
+
+assignManageRealmRole() {
+  local realm="$1"
+  local aamBackendClientUuid="$2"
+
+  local serviceAccountUserId
+  serviceAccountUserId=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$aamBackendClientUuid/service-account-user" \
+    -H "Authorization: Bearer $token" | jq -r '.id // empty')
+
+  if [ -z "$serviceAccountUserId" ]; then
+    echo "  WARNING: Could not get service account user for aam-backend client."
+    return 1
+  fi
+
+  local realmMgmtClientUuid
+  realmMgmtClientUuid=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients?clientId=realm-management" \
+    -H "Authorization: Bearer $token" | jq -r '.[0].id // empty')
+
+  local manageRealmRole
+  manageRealmRole=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$realmMgmtClientUuid/roles/manage-realm" \
+    -H "Authorization: Bearer $token")
+
+  curl -s -X POST "https://$KEYCLOAK_HOST/admin/realms/$realm/users/$serviceAccountUserId/role-mappings/clients/$realmMgmtClientUuid" \
+    -H "Authorization: Bearer $token" \
+    -H "Content-Type: application/json" \
+    -d "[$manageRealmRole]"
+
+  echo "  Ensured manage-realm role on aam-backend service account."
+
+  # ensure the "roles" client scope is assigned (required for role claims in the access token)
+  local rolesScopeUuid
+  rolesScopeUuid=$(curl -s -L "https://$KEYCLOAK_HOST/admin/realms/$realm/client-scopes" \
+    -H "Authorization: Bearer $token" | jq -r '.[] | select(.name == "roles") | .id // empty')
+
+  if [ -n "$rolesScopeUuid" ]; then
+    curl -s -X PUT "https://$KEYCLOAK_HOST/admin/realms/$realm/clients/$aamBackendClientUuid/default-client-scopes/$rolesScopeUuid" \
+      -H "Authorization: Bearer $token"
+    echo "  Ensured 'roles' client scope on aam-backend client."
+  else
+    echo "  WARNING: Could not find 'roles' client scope in realm '$realm'."
+  fi
+}
+
+##############################
+# migrate one instance
+##############################
+
+migrate_instance() {
+  local instanceDir="$1"
+  local instance
+  instance=$(basename "$instanceDir")
+  instance=${instance#"$PREFIX"}
+
+  local envFile="$instanceDir/.env"
+  local appEnvFile="$instanceDir/config/aam-backend-service/application.env"
+
+  if [ ! -f "$envFile" ]; then
+    echo "[$instance] no .env file, skipping"
+    return
+  fi
+
+  local profile
+  profile=$(getVar "$envFile" COMPOSE_PROFILES)
+
+  # only full-stack instances need migration (permission check is only used by aam-backend-service)
+  if [ "$profile" != "full-stack" ]; then
+    echo "[$instance] profile=$profile — skipping (not full-stack)"
+    return
+  fi
+
+  echo "[$instance] migrating..."
+
+  # backup files before any modification
+  backupFile "$envFile"
+  backupFile "$instanceDir/docker-compose.yml"
+  [ -f "$appEnvFile" ] && backupFile "$appEnvFile"
+
+  # 0. Update docker-compose.yml from shared ndb-setup template
+  cp "$baseDirectory/ndb-setup/docker-compose.yml" "$instanceDir/docker-compose.yml"
+  echo "  Updated docker-compose.yml from ndb-setup template"
+
+  # 1. Add Keycloak vars to .env (for replication-backend)
+  ensureEnv "REPLICATION_BACKEND_KEYCLOAK_CLIENT_ID" "aam-backend" "$envFile"
+  ensureEnv "REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET" "" "$envFile"
+
+  # 2. Create aam-backend Keycloak client (or get existing) + assign manage-realm
+  if createOrGetKeycloakBackendClient "$instance"; then
+    if [ -n "$clientSecret" ]; then
+      setEnv "REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET" "$clientSecret" "$envFile"
+      echo "  Set REPLICATION_BACKEND_KEYCLOAK_CLIENT_SECRET in .env"
+    else
+      echo "  ERROR: Client created/fetched but secret could not be retrieved."
+      echo "  Skipping restart for $instance to avoid broken permission-check config."
+      return 1
+    fi
+  else
+    echo "  ERROR: Failed to create or get Keycloak backend client for $instance."
+    echo "  Skipping restart for this instance to avoid broken permission-check config."
+    return 1
+  fi
+
+  # 3. Ensure application.env has replication-backend basic auth vars
+  if [ -f "$appEnvFile" ]; then
+    local couchUser couchPass
+    couchUser=$(getVar "$envFile" COUCHDB_USER)
+    couchPass=$(getVar "$envFile" COUCHDB_PASSWORD)
+
+    ensureEnv "AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASEPATH" "http://replication-backend:5984" "$appEnvFile"
+    ensureEnv "AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASICAUTHUSERNAME" "$couchUser" "$appEnvFile"
+    ensureEnv "AAMREPLICATIONBACKENDCLIENTCONFIGURATION_BASICAUTHPASSWORD" "$couchPass" "$appEnvFile"
+  else
+    echo "  no application.env found — skipping aam-backend-service config"
+  fi
+
+  # 4. Restart
+  echo "  Restarting..."
+  (cd "$instanceDir" && docker compose down && docker compose pull && docker compose up -d)
+
+  echo "[$instance] done"
+  echo ""
+}
+
+##############################
+# main
+##############################
+
+if [ -n "${1:-}" ]; then
+  # single instance mode
+  path="$baseDirectory/$PREFIX$1"
+  if [ ! -d "$path" ]; then
+    echo "Instance directory not found: $path"
+    exit 1
+  fi
+  migrate_instance "$path"
+else
+  # all instances
+  if [ -z "${PREFIX:-}" ]; then
+    echo "ERROR: PREFIX is not set. Aborting to avoid operating on all directories."
+    exit 1
+  fi
+  cd "$baseDirectory"
+  for D in ${PREFIX}*; do
+    if [ -d "$D" ]; then
+      migrate_instance "$baseDirectory/$D"
+    fi
+  done
+fi
+
+echo "Migration complete."