diff --git a/book/src/configuration/configurability.md b/book/src/configuration/configurability.md
index d691bf394c..c9dc95df79 100644
--- a/book/src/configuration/configurability.md
+++ b/book/src/configuration/configurability.md
@@ -547,7 +547,7 @@ values files.
 | `REGISTRY_PULL_SECRET` | Raw registry API key | **Raw key string** (e.g. `nvapi-...`). Not a file path. Not a JSON dockerconfig. |
 | `REGISTRY_PULL_USERNAME` | Registry username | Defaults to `$oauthtoken` (correct for `nvcr.io`) |
 | `KUBECONFIG` | Cluster kubeconfig | Filesystem path |
-| `NICO_SITE_UUID` | Stable UUID for this site | UUIDv4. Defaults to a fixed dev UUID — override per real site. |
+| `NICO_SITE_UUID` | Stable UUID for this site | UUIDv4. If unset, `setup.sh` generates a random UUID each run. |
 | `PREFLIGHT_CHECK_IMAGE` | Image for per-node preflight checks | Defaults to `busybox:1.36`. Override for air-gapped clusters. |
 
 Inside the cluster, `nico-api` discovers Vault, Postgres, and SPIFFE settings
diff --git a/docs/getting-started/quick-start.md b/docs/getting-started/quick-start.md
index b00ee43f2c..99d4350e6e 100644
--- a/docs/getting-started/quick-start.md
+++ b/docs/getting-started/quick-start.md
@@ -89,7 +89,7 @@ Obtain an NGC API key at [ngc.nvidia.com](https://ngc.nvidia.com) → **API Keys
 | `NICO_CORE_IMAGE_TAG` | **Yes** | NICo Core image tag (e.g. `v2025.12.30`). |
 | `NICO_REST_IMAGE_TAG` | **Yes** | NICo REST image tag (e.g. `v1.0.4`). |
 | `KUBECONFIG` | **Yes** | Path to your cluster kubeconfig. |
-| `NICO_SITE_UUID` | No | Stable UUID for this site. Defaults to `a1b2c3d4-e5f6-4000-8000-000000000001`. |
+| `NICO_SITE_UUID` | No | Stable UUID for this site. If unset, `setup.sh` generates a random UUID each run. |
 
 ### 3b. Set your Site Name
 
@@ -245,7 +245,7 @@ All IPs must be within the `IPAddressPool` ranges you defined in `values/metallb
 
 ### 3i. (Optional) Set a Stable Site UUID
 
-If you want a specific site UUID instead of the default placeholder, set the `NICO_SITE_UUID` environment variable:
+If you want a specific site UUID instead of a random UUID generated by `setup.sh`, set the `NICO_SITE_UUID` environment variable:
 
 ```bash
 export NICO_SITE_UUID=<your-uuid>   # must be a valid UUID v4
diff --git a/helm-prereqs/README.md b/helm-prereqs/README.md
index fc1361d9b7..b1b5429dec 100644
--- a/helm-prereqs/README.md
+++ b/helm-prereqs/README.md
@@ -101,7 +101,7 @@ The tables below summarize the keys that must be set per site.
 | `NICO_IMAGE_REGISTRY` | Yes, unless `--skip-core --skip-rest` | Base image registry for all NICo images (e.g. `my-registry.example.com/nico`) |
 | `NICO_CORE_IMAGE_TAG` | Yes, unless `--skip-core` | NICo Core image tag (e.g. `v2025.12.30-rc1`) |
 | `NICO_REST_IMAGE_TAG` | Yes, unless `--skip-rest` | NICo REST image tag (e.g. `v1.0.4`) |
-| `NICO_SITE_UUID` | No | Stable UUID for this site. Defaults to `a1b2c3d4-e5f6-4000-8000-000000000001`. |
+| `NICO_SITE_UUID` | No | Stable UUID for this site. If unset, `setup.sh` generates a random UUID each run. |
 | `NICO_MANAGE_DEFAULT_STORAGE_CLASS` | No | Whether `setup.sh` marks `local-path` as the default StorageClass. Defaults to `true`. Set to `false` when the cluster already has an operator-managed default StorageClass. |
 | `NICO_STORAGE_CLASS` | No | StorageClass used by Vault data/audit PVCs. Defaults to `local-path-persistent`. |
 | `PREFLIGHT_CHECK_IMAGE` | No | Image used for preflight per-node checks. Defaults to `busybox:1.36`; set to a local mirror for air-gapped clusters. |
diff --git a/helm-prereqs/setup.sh b/helm-prereqs/setup.sh
index 09e67140b7..d907a665b7 100755
--- a/helm-prereqs/setup.sh
+++ b/helm-prereqs/setup.sh
@@ -37,8 +37,8 @@
 #                          preloaded, or use existing imagePullSecrets.
 #   REGISTRY_PULL_USERNAME Username for generated pull secrets.
 #                          Default: $oauthtoken
-#   NICO_SITE_UUID          Stable REST site UUID. Used only when REST is
-#                          deployed. Default is a dev placeholder.
+#   NICO_SITE_UUID          REST site UUID. Used only when REST is deployed.
+#                          If unset, setup generates a random UUID each run.
 #   NICO_MANAGE_DEFAULT_STORAGE_CLASS
 #                          Whether setup annotates local-path as the default
 #                          StorageClass. Default: true.
@@ -629,13 +629,82 @@ _TEMPORAL_TLS="--tls-cert-path /var/secrets/temporal/certs/server-interservice/t
     --tls-key-path /var/secrets/temporal/certs/server-interservice/tls.key \
     --tls-ca-path /var/secrets/temporal/certs/server-interservice/ca.crt \
     --tls-server-name interservice.server.temporal.local"
-kubectl exec -n temporal deploy/temporal-admintools -- \
-    sh -c "temporal operator namespace create -n cloud --retention 72h --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" 2>/dev/null || true
-kubectl exec -n temporal deploy/temporal-admintools -- \
-    sh -c "temporal operator namespace create -n site --retention 72h --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" 2>/dev/null || true
+_wait_for_temporal() {
+    local _output=""
+
+    echo "Waiting for Temporal frontend and admin tools..."
+    kubectl rollout status deploy/temporal-frontend -n temporal --timeout=120s
+    kubectl rollout status deploy/temporal-admintools -n temporal --timeout=120s
+
+    for _i in $(seq 1 24); do
+        if _output="$(kubectl exec -n temporal deploy/temporal-admintools -- \
+            sh -c "temporal operator namespace list --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" 2>&1)"; then
+            echo "Temporal frontend ready"
+            return
+        fi
+        echo "  Waiting for Temporal API (${_i}/24)..."
+        sleep 5
+    done
+
+    echo "ERROR: Temporal frontend is not ready for namespace operations" >&2
+    echo "${_output}" >&2
+    exit 1
+}
+
+_create_temporal_namespace() {
+    local _namespace="$1"
+    local _output
+
+    if _output="$(kubectl exec -n temporal deploy/temporal-admintools -- \
+        sh -c "temporal operator namespace create -n \"\$1\" --retention 72h --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" \
+        sh "${_namespace}" 2>&1)"; then
+        echo "Temporal namespace ${_namespace} ready"
+        return
+    fi
+
+    if printf "%s" "${_output}" | grep -qi "already exists"; then
+        echo "Temporal namespace ${_namespace} already exists"
+        return
+    fi
+
+    echo "ERROR: failed to create Temporal namespace ${_namespace}" >&2
+    echo "${_output}" >&2
+    exit 1
+}
+
+_verify_temporal_namespaces() {
+    local _output
+    local _missing=()
+    local _namespace
+
+    if ! _output="$(kubectl exec -n temporal deploy/temporal-admintools -- \
+        sh -c "temporal operator namespace list --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" 2>&1)"; then
+        echo "ERROR: failed to list Temporal namespaces" >&2
+        echo "${_output}" >&2
+        exit 1
+    fi
+
+    for _namespace in "$@"; do
+        if ! printf "%s" "${_output}" | grep -Eq "(^|[^[:alnum:]_-])${_namespace}([^[:alnum:]_-]|$)"; then
+            _missing+=("${_namespace}")
+        fi
+    done
+
+    if [[ ${#_missing[@]} -gt 0 ]]; then
+        echo "ERROR: missing Temporal namespace(s): ${_missing[*]}" >&2
+        echo "${_output}" >&2
+        exit 1
+    fi
+
+    echo "Verified Temporal namespaces: $*"
+}
+
+_wait_for_temporal
+_create_temporal_namespace cloud
+_create_temporal_namespace site
 # flow Temporal namespace — required by NICo Flow workers; pod panics on startup if absent.
-kubectl exec -n temporal deploy/temporal-admintools -- \
-    sh -c "temporal operator namespace create -n flow --retention 72h --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" 2>/dev/null || true
+_create_temporal_namespace flow
+_verify_temporal_namespaces cloud site flow
 echo "Temporal namespaces ready"
 
 _SETUP_PHASE="[7g/7] NICo REST helm chart"
@@ -710,8 +779,13 @@ fi
 # All of this is wired via --set flags so nico-rest.yaml stays registry-agnostic.
 NICO_SITE_AGENT_CHART="${NICO_REST_HELM_DIR}/nico-rest-site-agent"
 
-# Stable placeholder UUID for this site (must be a valid UUID).
-NICO_SITE_UUID="${NICO_SITE_UUID:-a1b2c3d4-e5f6-4000-8000-000000000001}"
+if [[ -z "${NICO_SITE_UUID:-}" ]]; then
+    if ! command -v python3 &>/dev/null; then
+        echo "ERROR: NICO_SITE_UUID is unset and python3 is not available" >&2
+        exit 1
+    fi
+    NICO_SITE_UUID="$(python3 -c 'import uuid; print(uuid.uuid4())')"
+fi
 
 NICO_SITE_AGENT_ARGS=(
     --namespace nico-rest
@@ -762,8 +836,8 @@ _TEMPORAL_TLS="--tls-cert-path /var/secrets/temporal/certs/server-interservice/t
     --tls-key-path /var/secrets/temporal/certs/server-interservice/tls.key \
     --tls-ca-path /var/secrets/temporal/certs/server-interservice/ca.crt \
     --tls-server-name interservice.server.temporal.local"
-kubectl exec -n temporal deploy/temporal-admintools -- \
-    sh -c "temporal operator namespace create -n '${NICO_SITE_UUID}' --retention 72h --address ${_TEMPORAL_ADDR} ${_TEMPORAL_TLS}" 2>/dev/null || true
+_create_temporal_namespace "${NICO_SITE_UUID}"
+_verify_temporal_namespaces "${NICO_SITE_UUID}"
 echo "Temporal namespace ready"
 
 # FLOW_GRPC_ENABLED toggles the site-agent's Flow gRPC client (see
diff --git a/helm-prereqs/values/nico-rest.yaml b/helm-prereqs/values/nico-rest.yaml
index 02da3426a3..fa7d404f79 100644
--- a/helm-prereqs/values/nico-rest.yaml
+++ b/helm-prereqs/values/nico-rest.yaml
@@ -38,45 +38,3 @@ nico-rest-workflow:
     replicaCount: 3
   siteWorker:
     replicaCount: 3
-
-# Site-agent config — v1.0.4 binary reads DB config from env vars.
-# NICo postgres uses the 'nico' user and 'elektratest' database.
-# CLUSTER_ID and TEMPORAL_SUBSCRIBE_* are set via --set in setup.sh
-# using the NICO_SITE_UUID variable (default: a1b2c3d4-e5f6-4000-8000-000000000001).
-nico-rest-site-agent:
-  replicaCount: 3
-  bootstrap:
-    enabled: true
-    siteManager:
-      address: "nico-rest-site-manager.nico-rest:8100"
-  certificate:
-    # Service identifier must match "elektra-site-agent" for nico-api's SiteAgent RBAC role.
-    # The base path /nico-system/sa/ is one of nico-api's recognized spiffe_service_base_paths.
-    uris:
-      - "spiffe://nico.local/nico-system/sa/elektra-site-agent"
-  envConfig:
-    # DEV ONLY — these values match the dev postgres instance deployed by setup.sh.
-    # DB_USER and DB_PASSWORD are injected from the db-creds Secret (secrets.dbCreds).
-    DB_ADDR: "postgres.postgres.svc.cluster.local"
-    DB_DATABASE: "elektratest"
-    DB_PORT: "5432"
-    ESA_PORT: "8080"
-    METRICS_PORT: "2112"
-    DEV_MODE: "true"
-    ENABLE_DEBUG: "true"
-    ENABLE_TLS: "true"
-    # mTLS to nico-api (NICO_SEC_OPT=2). Cert issued from vault-nico-issuer
-    # so nico-api trusts it (same Vault PKI CA as nico-api's own cert).
-    NICO_ADDRESS: "nico-api.nico-system.svc.cluster.local:1079"
-    NICO_SEC_OPT: "2"
-    CLUSTER_ID: "a1b2c3d4-e5f6-4000-8000-000000000001"
-    TEMPORAL_HOST: "temporal-frontend.temporal"
-    TEMPORAL_PORT: "7233"
-    TEMPORAL_SERVER: "interservice.server.temporal.local"
-    TEMPORAL_PUBLISH_NAMESPACE: "site"
-    TEMPORAL_PUBLISH_QUEUE: "site"
-    TEMPORAL_SUBSCRIBE_NAMESPACE: "a1b2c3d4-e5f6-4000-8000-000000000001"
-    TEMPORAL_SUBSCRIBE_QUEUE: "site"
-    TEMPORAL_INVENTORY_SCHEDULE: "@every 3m"
-    TEMPORAL_CERT_PATH: "/etc/temporal-certs"
-    TEMPORAL_CERT: "temporal-client-site-agent-certs"