diff --git a/scripts/CHANGELOG.md b/scripts/CHANGELOG.md
index 823cbd0..bdecfc2 100644
--- a/scripts/CHANGELOG.md
+++ b/scripts/CHANGELOG.md
@@ -1,5 +1,26 @@
 # Felhom scripts — Changelog
 
+## felhom-host-install.sh v1.4.0 — appliance CPU/RAM cap passthrough (`--cores` / `--memory`) (2026-07-01)
+
+Colleague-safety batch #3 (host-install half; the mechanism is agent v0.52.0). Lets an operator cap the
+provisioned guest so a trial appliance on a SHARED production Proxmox doesn't pressure the colleague's
+existing guests.
+
+- **`--cores N` / `--memory M` (MiB)** — optional; passed through to the agent's `--selftest=provision`
+  as `-cores`/`-memory`. `0`/unset = keep the golden's baked sizes (unchanged behaviour). New vars
+  `CPU_CORES`/`MEM_MIB`; `usage()` header gains an "Appliance cap (optional)" group.
+- **Conditional passthrough** — `step_provision` builds a `cap_args` array and appends the flags to BOTH
+  the dry-run log and the real agent call **only when set**. An agent < v0.52.0 would reject an unknown
+  flag, so the flags are never sent unless the operator opts in (see the deploy dependency below).
+- **Pre-flight sanity WARN (soft, provision only)** — if `--cores` > host `nproc` or `--memory` > host
+  `MemTotal`, `log_warn` "the cap won't protect other guests"; never `die` (the operator may know better).
+- **Deploy dependency:** a fresh install using `--cores`/`--memory` needs the hub artifact manifest to
+  serve **agent ≥ v0.52.0**.
+- **Validated dry-run on felhom-pve:** `--cores 2 --memory 4096 --dry-run` → provision command shows
+  `-cores 2 -memory 4096`; without the flags → neither present; `--cores 64 --memory 65536` → both WARN
+  lines (host 4 cores / ~15771 MiB). `bash -n` + `shellcheck` clean (0 new warnings; the 2 pre-existing
+  SC2015 in `step_verify` unchanged).
+
 ## felhom-host-install.sh v1.3.0 — `--uninstall` (clean revert) + pre-flight guards (2026-07-01)
 
 Colleague-safety batch #1+#2. Adds a first-class, guarded **`--uninstall`** teardown so an operator can
diff --git a/scripts/felhom-host-install.sh b/scripts/felhom-host-install.sh
index 7e5a52b..0722078 100644
--- a/scripts/felhom-host-install.sh
+++ b/scripts/felhom-host-install.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 #===============================================================================
-# felhom-host-install.sh v1.3.0
+# felhom-host-install.sh v1.4.0
 # Day-0 host-bootstrap for a Felhom Proxmox host (operator-deploy model).
 #
 # Run by the operator on a FRESHLY-PVE-INSTALLED box (after a manual PVE install
@@ -45,6 +45,11 @@
 #   --rootfs-grow N         grow OS rootfs by N GiB  (default: auto-compute)
 #   --datavol-grow N        grow Docker-data vol by N GiB (default: auto-compute)
 #   --sysdata-grow N        grow user-data vol by N GiB (default: auto-compute)
+#
+#   Appliance cap (optional — protect a SHARED host's other guests; needs agent >= v0.52.0):
+#   --cores N               cap the guest to N CPU cores  (0/unset = golden default)
+#   --memory M              cap the guest RAM to M MiB     (0/unset = golden default)
+#
 #   --passphrase-file PATH  read the retrieval passphrase from a 0600 file
 #                           (default: secure no-echo prompt)
 #   --preserve-from PATH    merge non-Day-0 sections (privileged/storage/backup/
@@ -85,7 +90,7 @@
 
 set -euo pipefail
 
-SCRIPT_VERSION="1.3.0"
+SCRIPT_VERSION="1.4.0"
 
 #-------------------------------------------------------------------------------
 # Logging (mirrors felhom-controller/scripts/docker-setup.sh)
@@ -118,6 +123,8 @@ BRIDGE_ADDR=""
 ROOTFS_GROW=""
 DATAVOL_GROW=""
 SYSDATA_GROW=""
+CPU_CORES=""             # --cores: optional appliance CPU-core cap (empty/unset = golden default)
+MEM_MIB=""               # --memory: optional appliance RAM cap in MiB (empty/unset = golden default)
 PASSPHRASE_FILE=""
 PRESERVE_FROM=""
 PRESERVE_STATE_FROM=""   # dir holding a prior local-api.{crt,key} + local-tokens.log to carry over (keeps the pin stable across a reinstall)
@@ -166,7 +173,7 @@ ART_GOLDEN_SHA=""
 #-------------------------------------------------------------------------------
 # Helpers
 #-------------------------------------------------------------------------------
-usage() { sed -n '2,75p' "$0" | sed 's/^# \{0,1\}//'; exit 0; }
+usage() { sed -n '2,80p' "$0" | sed 's/^# \{0,1\}//'; exit 0; }
 
 run() {  # simple (no pipes/redirects) mutating command
     if $DRY_RUN; then log_dry "$*"; else "$@"; fi
@@ -478,6 +485,8 @@ while [[ $# -gt 0 ]]; do
         --rootfs-grow)     ROOTFS_GROW="$2"; shift 2 ;;
         --datavol-grow)    DATAVOL_GROW="$2"; shift 2 ;;
         --sysdata-grow)    SYSDATA_GROW="$2"; shift 2 ;;
+        --cores)           CPU_CORES="$2"; shift 2 ;;
+        --memory)          MEM_MIB="$2"; shift 2 ;;
         --passphrase-file) PASSPHRASE_FILE="$2"; shift 2 ;;
         --preserve-from)   PRESERVE_FROM="$2"; shift 2 ;;
         --preserve-state-from) PRESERVE_STATE_FROM="$2"; shift 2 ;;
@@ -621,6 +630,23 @@ step_preflight() {
         fi
     fi
 
+    # Appliance-cap sanity (soft): a cap that EXCEEDS host resources won't protect other guests. WARN,
+    # never die — the operator may know better (e.g. capping below a future hardware upgrade).
+    if ! $SKIP_PROVISION; then
+        if [[ -n "$CPU_CORES" ]]; then
+            local host_cores; host_cores=$(nproc 2>/dev/null || echo 0)
+            if [[ "${host_cores:-0}" -gt 0 && "$CPU_CORES" -gt "$host_cores" ]]; then
+                log_warn "  requested cap (${CPU_CORES} cores) exceeds host cores (${host_cores}); the cap won't protect other guests."
+            fi
+        fi
+        if [[ -n "$MEM_MIB" ]]; then
+            local host_mem_mib; host_mem_mib=$(awk '/^MemTotal:/{print int($2/1024)}' /proc/meminfo 2>/dev/null || echo 0)
+            if [[ "${host_mem_mib:-0}" -gt 0 && "$MEM_MIB" -gt "$host_mem_mib" ]]; then
+                log_warn "  requested cap (${MEM_MIB} MiB) exceeds host RAM (~${host_mem_mib} MiB); the cap won't protect other guests."
+            fi
+        fi
+    fi
+
     # archive-storage-exists guard (provision only — the golden lives there + the restore reads it).
     if ! $SKIP_PROVISION; then
         if pvesm status --storage "$ARCHIVE_STORAGE" >/dev/null 2>&1; then
@@ -1100,15 +1126,21 @@ step_provision() {
     log_step "8/8 provision guest $VMID"
     # NOTE: -hub-password is passed on argv (the agent's only input for it) — briefly
     # visible in ps. Tracked as an Observation (candidate: env/stdin in the agent).
+    # Optional operator CPU/RAM cap — passed to the agent ONLY when set (an agent < v0.52.0 would
+    # reject the unknown flag and die; opt-in means no one hits that until they intentionally cap).
+    local -a cap_args=()
+    [[ -n "$CPU_CORES" ]] && cap_args+=(-cores "$CPU_CORES")
+    [[ -n "$MEM_MIB"   ]] && cap_args+=(-memory "$MEM_MIB")
     if $DRY_RUN; then
-        log_dry "felhom-agent --config $AGENT_CONFIG --selftest=provision -archive $GOLDEN_VOLID -vmid $VMID -customer-id $CUSTOMER_ID -hub-password <pass> -rootfs-grow $ROOTFS_GROW -datavol-grow $DATAVOL_GROW -sysdata-grow $SYSDATA_GROW"
+        log_dry "felhom-agent --config $AGENT_CONFIG --selftest=provision -archive $GOLDEN_VOLID -vmid $VMID -customer-id $CUSTOMER_ID -hub-password <pass> -rootfs-grow $ROOTFS_GROW -datavol-grow $DATAVOL_GROW -sysdata-grow $SYSDATA_GROW ${cap_args[*]}"
         log_dry "record provisioned_vmid=$VMID in $STATE_FILE (for a later automatic --uninstall)"
         _state_mark provision; return 0
     fi
     if ! felhom-agent --config "$AGENT_CONFIG" --selftest=provision \
         -archive "$GOLDEN_VOLID" -vmid "$VMID" \
         -customer-id "$CUSTOMER_ID" -hub-password "$PASSPHRASE" \
-        -rootfs-grow "$ROOTFS_GROW" -datavol-grow "$DATAVOL_GROW" -sysdata-grow "$SYSDATA_GROW"; then
+        -rootfs-grow "$ROOTFS_GROW" -datavol-grow "$DATAVOL_GROW" -sysdata-grow "$SYSDATA_GROW" \
+        "${cap_args[@]}"; then
         die "provision FAILED — see the agent error above. Fix and re-run with --resume."
     fi
     log_success "  provision completed"