rotate egress over a larger WG pool, with graceful drain and live status

Keep the N always-on tunnel slots fixed but let each slot's WireGuard config
rotate through a larger pool, so a 10-concurrent provider cap (e.g. Proton) can
still cycle 50-100 profiles.

- lxc/rotate.sh + weircon-rotate.{service,timer}: round-robin one slot at a
  time through wg-pool/, repointing a symlink and restarting only that slot.
- service: proxyManager tracks per-slot in-flight + drain/undrain state; a
  localhost admin server (WEIRCON_ADMIN_LISTEN) lets rotate.sh drain a slot
  before teardown and warm it back in after, so no request is routed to a
  tunnel mid-rotation. Slots self-heal if undrain never arrives.
- GET /status: poll-friendly JSON of per-slot egress IP/state plus inferred
  next-rotation slot + ETA, fed by a background egress-IP prober.
- docs + env examples for all new knobs.

.gitignore

@@ -1,3 +1,4 @@
 wg-configs/*.conf
 *.env
 service/weircon-random-proxy
+service/random-proxy

README.md

@@ -56,6 +56,39 @@ Use it whenever you need an HTTP-facing API that returns results from rotating e
 
 Tunnel count is configurable. Default deploy uses 10 tunnels; the WireGuard configs themselves can come from any provider that gives you a standard `[Interface] / [Peer]` config (ProtonVPN, Mullvad, AzireVPN, self-hosted, …). Drop the configs into `/etc/weircon-random-proxy/wg/proxy<N>.conf` and the rest is identical.
 
+### Rotating over more configs than tunnels
+
+A slot (netns `proxy<N>`, fixed IP, fixed SOCKS port) is decoupled from the WireGuard config it carries. `netns-up.sh` just reads `wg/proxy<N>.conf`, and that path can be a **symlink** into a larger pool. So if your provider caps concurrent connections (ProtonVPN allows 10) but you hold 50–100 configs, keep the 10 always-on slots and rotate *which config each slot points at*:
+
+```
+/etc/weircon-random-proxy/
+  wg-pool/                 ← all your configs (proton-001.conf … proton-100.conf)
+  wg/
+    proxy0.conf -> ../wg-pool/proton-047.conf   ← symlink, repointed over time
+    …
+    proxy9.conf -> ../wg-pool/proton-088.conf
+```
+
+`weircon-rotate.timer` fires `rotate.sh`, which advances **one slot at a time** to the next unused config in the pool and restarts only that slot. The other 9 stay up, so there is always egress; over a full cycle every config gets used. Because `weircon-proxy@.service` tears the old tunnel down before raising the new one, a slot is never doubly-connected — you never exceed the provider's concurrent limit, even mid-rotation.
+
+**Graceful drain.** So a request is never handed to a tunnel that's about to disappear, `rotate.sh` coordinates with the service over a localhost-only admin API before touching a slot:
+
+1. `POST /drain?id=N` — the service stops routing **new** requests to slot N and blocks until that slot's in-flight requests finish (bounded by `WEIRCON_DRAIN_TIMEOUT_SEC`), plus a short `WEIRCON_DRAIN_SETTLE_SEC` quiet period.
+2. The symlink is repointed and the tunnel unit restarted.
+3. `POST /undrain?id=N` — slot N is returned to service, but held out of the candidate set for `WEIRCON_DRAIN_WARMUP_SEC` so the fresh WireGuard handshake can settle before traffic resumes.
+
+Random picks skip draining/warming slots automatically; a request that *pins* a slot mid-rotation gets `503` + `Retry-After`. If `rotate.sh` ever dies between drain and undrain, the slot self-heals after `WEIRCON_DRAIN_MAX_HOLD_SEC` so the pool can't shrink permanently. The admin server binds `127.0.0.1:8081` by default — keep it off your reverse proxy. `GET /status` returns a per-slot snapshot (in-flight / draining / warming).
+
+```sh
+cp proton-*.conf /etc/weircon-random-proxy/wg-pool/   # the pool (not in git)
+weircon-rotate init                                    # seed 10 distinct symlinks
+systemctl restart weircon-proxy@{0..9}.service
+systemctl enable --now weircon-rotate.timer            # auto-rotate (default every 5 min)
+systemctl edit weircon-rotate.timer                    # change interval (OnUnitActiveSec)
+```
+
+The fetch service is unaware of any of this — it still sees 10 fixed SOCKS endpoints. The only observable change is that the egress IP behind a given `X-WEIRCON-PROXY-ID` drifts over time. (Trade-off: restarting a slot drops requests in flight on that one slot for the ~1–2 s WireGuard handshake; one-at-a-time rotation keeps the blast radius to a single slot.)
+
 ## Client API
 
 Fetch a URL through a random tunnel:
@@ -97,6 +130,37 @@ curl -H "X-WEIRCON-RANDOM-IP: $API_KEY" \
 
 Status, headers, and body of the upstream response are returned directly. The service adds `X-WEIRCON-EGRESS-PROXY: <id>` so the caller can see which tunnel was used.
 
+### Live status (`/status`)
+
+`GET /status` returns a poll-friendly JSON snapshot for scraper-side dashboards — cheap to produce (no network I/O in the request path; egress IPs come from a background prober) and safe to hit every 1–5 s. It's behind the same API-key gate as `/`.
+
+```bash
+curl -H "X-WEIRCON-RANDOM-IP: $API_KEY" https://random-proxy.example.com/status
+```
+
+```jsonc
+{
+  "now": "2026-06-01T08:47:18Z",
+  "proxies_total": 10,
+  "available": 9,                  // slots currently selectable (not draining/warming)
+  "proxies": [
+    { "id": 0, "state": "live",     "inflight": 2, "egress_ip": "185.x.x.10", "reachable": true,  "latency_ms": 42, "checked_age_sec": 7 },
+    { "id": 1, "state": "draining", "inflight": 0, "egress_ip": "185.x.x.11", "reachable": true,  "latency_ms": 51, "checked_age_sec": 9 },
+    // …
+  ],
+  "rotation": {
+    "next_slot": 2,                 // which slot rotates next (round-robin)
+    "next_egress_ip": "185.x.x.12", // the egress IP about to be replaced
+    "eta_sec": 137,                 // seconds until the next rotation
+    "interval_sec": 300,
+    "last_slot": 1,                 // slot that rotated most recently
+    "last_rotated_age_sec": 163
+  }
+}
+```
+
+Per-slot `state` is `live` (selectable), `draining` (in-flight finishing, about to be torn down), or `warming` (new tunnel up, settling before traffic resumes) — drive your visual "rotating now" indicator off the latter two. The `rotation` block tells you *when* the next rotation lands and *which* egress IP it will replace, so you can show a countdown and flag the outgoing IP ahead of time. The `rotation` fields stay absent until enough rotations have happened to infer the cadence (≈ two timer ticks after boot); egress fields are absent when probing is disabled.
+
 ## Built-in API tester (`/ui`)
 
 The fetch service ships with an embedded HTML page at `/ui` that documents the API and lets you exercise every endpoint interactively:
@@ -119,10 +183,14 @@ The UI is enabled by default. Set `WEIRCON_UI_ENABLED=false` in `fetch.env` to d
 | `lxc/setup-container.sh`            | Runs **inside** the LXC: apt deps, microsocks, helper scripts, systemd units. |
 | `lxc/netns-up.sh`                   | Brings one tunnel namespace up (`proxy<N>` with wg0 + veth + bridge).         |
 | `lxc/netns-down.sh`                 | Tears it back down (invoked by systemd ExecStopPost).                         |
+| `lxc/rotate.sh`                     | Rotates one slot to the next pool config; `init` seeds the slots.             |
 | `lxc/systemd/weircon-proxies.target`| Grouping target for all tunnels.                                              |
 | `lxc/systemd/weircon-proxy@.service`| Templated unit. Enable with `weircon-proxy@{0..N-1}.service`.                 |
+| `lxc/systemd/weircon-rotate.service`| Oneshot that runs `rotate.sh` (one slot per invocation).                      |
+| `lxc/systemd/weircon-rotate.timer`  | Fires the rotation on an interval (default 5 min; `systemctl edit` to change).|
 | `lxc/systemd/weircon-fetch.service` | The fetch service itself. Hardened (DynamicUser, no capabilities).            |
 | `lxc/fetch.env.example`             | Default env. Copy to `/etc/weircon-random-proxy/fetch.env`.                   |
+| `lxc/rotate.env.example`            | Rotation env (`SLOTS`). Copy to `/etc/weircon-random-proxy/rotate.env`.       |
 | `npm/advanced.conf`                 | Reverse-proxy snippet: header check, strip, forward.                          |
 | `wg-configs/`                       | Local placeholder. Actual `.conf` files live on the LXC, **not** in git.      |
 
@@ -137,6 +205,14 @@ The UI is enabled by default. Set `WEIRCON_UI_ENABLED=false` in `fetch.env` to d
 | `WEIRCON_PROXY_COUNT`          | `10`                     | Number of fallback endpoints.                                     |
 | `WEIRCON_REQUEST_TIMEOUT_SEC`  | `30`                     | Per-upstream-fetch ceiling.                                       |
 | `WEIRCON_UI_ENABLED`           | `true`                   | Toggle the embedded `/ui` page.                                   |
+| `WEIRCON_ADMIN_LISTEN`         | `127.0.0.1:8081`         | Localhost drain/undrain API for rotation. Empty disables it.      |
+| `WEIRCON_DRAIN_TIMEOUT_SEC`    | `25`                     | Max wait for a slot's in-flight requests to clear during drain.   |
+| `WEIRCON_DRAIN_SETTLE_SEC`     | `2`                      | Quiet period after in-flight hits zero (the "couple secs before").|
+| `WEIRCON_DRAIN_WARMUP_SEC`     | `3`                      | Slot held out of rotation after undrain (the "couple secs after").|
+| `WEIRCON_DRAIN_MAX_HOLD_SEC`   | `60`                     | Auto-undrain safety if `rotate.sh` dies between drain and undrain.|
+| `WEIRCON_PROBE_URL`            | `https://api.ipify.org`  | IP-echo URL the prober fetches through each tunnel for `/status`. |
+| `WEIRCON_PROBE_INTERVAL_SEC`   | `60`                     | Egress-IP probe cadence. `0` disables probing (`egress_ip` empty).|
+| `WEIRCON_PROBE_TIMEOUT_SEC`    | `10`                     | Per-probe ceiling.                                                |
 
 If `WEIRCON_PROXY_ADDRS` is set it wins; otherwise the service computes `WEIRCON_PROXY_HOST:WEIRCON_PROXY_BASE_PORT + i` for `i` in `[0, WEIRCON_PROXY_COUNT)`.
 

lxc/fetch.env.example

@@ -7,3 +7,28 @@ WEIRCON_PROXY_ADDRS=10.99.0.10:1080,10.99.0.11:1080,10.99.0.12:1080,10.99.0.13:1
 
 # Maks tid pr. upstream-fetch (sekunder).
 WEIRCON_REQUEST_TIMEOUT_SEC=30
+
+# Admin-endpoint til rotation (drain/undrain). Kun localhost — må ALDRIG
+# eksponeres via reverse-proxy. Tom streng slår admin-serveren helt fra.
+WEIRCON_ADMIN_LISTEN=127.0.0.1:8081
+
+# Rotation-drænings-tuning (sekunder):
+#   TIMEOUT = maks ventetid på at in-flight requests på en slot tømmes
+#   SETTLE  = ekstra ro-periode efter in-flight = 0 ("et par sek. før")
+#   WARMUP  = slot holdes ude af rotation efter undrain, så WG-handshaket
+#             kan sætte sig ("et par sek. efter")
+#   MAX_HOLD= sikkerhed: slot self-healer og kommer tilbage selv hvis
+#             rotate.sh dør mellem drain og undrain
+WEIRCON_DRAIN_TIMEOUT_SEC=25
+WEIRCON_DRAIN_SETTLE_SEC=2
+WEIRCON_DRAIN_WARMUP_SEC=3
+WEIRCON_DRAIN_MAX_HOLD_SEC=60
+
+# Egress-IP prober: henter den aktuelle udgangs-IP gennem hver tunnel og cacher
+# den, så /status kan vise hvilken IP der sidder på hver slot (og hvilken der
+# snart roteres ud). INTERVAL=0 slår probing helt fra (så er egress_ip tom i
+# /status, og klienten må selv probe). URL skal returnere klientens IP som ren
+# tekst (ipify, ifconfig.me/ip, egen endpoint, …).
+WEIRCON_PROBE_URL=https://api.ipify.org
+WEIRCON_PROBE_INTERVAL_SEC=60
+WEIRCON_PROBE_TIMEOUT_SEC=10

lxc/rotate.env.example

@@ -0,0 +1,6 @@
+# Kopiér til /etc/weircon-random-proxy/rotate.env (valgfrit).
+# Læses af weircon-rotate.service.
+
+# Antal aktive tunnel-slots. SKAL matche det weircon-proxy@N-interval du har
+# enablet (fx weircon-proxy@{0..9} => SLOTS=10). Default hvis usat: 10.
+SLOTS=10

lxc/rotate.sh

@@ -0,0 +1,133 @@
+#!/bin/bash
+# Roterer ÉN tunnel-slot ad gangen til den næste WG-config i puljen.
+#
+#   - Slots (netns proxy0..proxy<SLOTS-1>) er faste: faste IP'er, faste
+#     SOCKS-porte. Fetch-servicen kender kun de faste endpoints.
+#   - Configs ligger i en pulje (wg-pool/) der kan være større end SLOTS.
+#   - Hver slot's aktive config er et symlink:
+#         wg/proxy<ID>.conf -> wg-pool/<navn>.conf
+#   - Hvert kald her flytter præcis én slot videre til næste ledige config
+#     i puljen og genstarter kun den slot. De øvrige 9 bliver oppe, så der
+#     altid er egress ud — og over tid cykler alle configs igennem.
+#
+# Hvorfor én ad gangen: holder os trygt inden for udbyderens samtidigheds-
+# grænse (fx Proton: max 10 samtidige WG-sessioner) og dropper aldrig al
+# egress på én gang. weircon-proxy@.service river desuden den gamle tunnel
+# ned (ExecStopPost) FØR den nye rejses (ExecStartPre), så en slot er aldrig
+# dobbelt-forbundet midt i en rotation.
+#
+# Brug:
+#   rotate.sh          # roter én slot (cursor i state-filen rykker)
+#   rotate.sh init     # seed alle slots med de første SLOTS distinkte configs
+set -euo pipefail
+
+POOL="/etc/weircon-random-proxy/wg-pool"
+ACTIVE="/etc/weircon-random-proxy/wg"
+STATE="/var/lib/weircon-random-proxy/rotate.state"
+SLOTS="${SLOTS:-10}"
+# Fetch-servicens admin-endpoint (lokal, ikke eksponeret via reverse-proxy).
+# Tom => spring drain/undrain over (falder tilbage til ren restart).
+ADMIN_URL="${WEIRCON_ADMIN_URL:-http://127.0.0.1:8081}"
+
+# Pulje-configs, sorteret og stabilt ordnet (kun basenavne).
+mapfile -t POOL_CONFIGS < <(find "$POOL" -maxdepth 1 -type f -name '*.conf' -printf '%f\n' 2>/dev/null | sort)
+N="${#POOL_CONFIGS[@]}"
+if (( N == 0 )); then
+    echo "ingen configs i $POOL — læg proton-*.conf filer der" >&2
+    exit 1
+fi
+if (( N < SLOTS )); then
+    echo "WARN: kun $N configs i puljen til $SLOTS slots — der vil være gengangere" >&2
+fi
+
+# Hvilke configs er allerede i brug af en ANDEN slot end $skip_slot?
+configs_in_use() {
+    local skip="$1" i link
+    for (( i = 0; i < SLOTS; i++ )); do
+        (( i == skip )) && continue
+        link="$ACTIVE/proxy${i}.conf"
+        [[ -L "$link" ]] && basename "$(readlink -f "$link")"
+    done
+}
+
+# Find næste config i puljen fra position $1 som ikke er i $2..(resten).
+# Sætter globalt $CHOSEN og $NEXT_POS.
+pick_free_config() {
+    local start="$1" skip_slot="$2" k cand
+    local -a busy
+    mapfile -t busy < <(configs_in_use "$skip_slot")
+    for (( k = 0; k < N; k++ )); do
+        cand="${POOL_CONFIGS[(start + k) % N]}"
+        if ! printf '%s\n' "${busy[@]}" | grep -qxF "$cand"; then
+            CHOSEN="$cand"
+            NEXT_POS=$(( (start + k + 1) % N ))
+            return 0
+        fi
+    done
+    return 1
+}
+
+# Bed fetch-servicen om at stoppe ny trafik til en slot og vente til
+# in-flight er drænet (servicen håndterer selv ventetid + settle). Stille
+# no-op hvis admin-endpointet ikke svarer (fx UI/service slået fra).
+drain_slot() {
+    local slot="$1"
+    [[ -z "$ADMIN_URL" ]] && return 0
+    curl -fsS -m 60 -X POST "${ADMIN_URL}/drain?id=${slot}" >/dev/null 2>&1 || \
+        echo "WARN: drain af slot $slot fejlede (fortsætter)" >&2
+}
+
+# Giv slot tilbage til servicen. Servicen holder den selv ude af rotation et
+# par sekunder mere (warmup) så den friske WG-handshake kan nå at sætte sig.
+undrain_slot() {
+    local slot="$1"
+    [[ -z "$ADMIN_URL" ]] && return 0
+    curl -fsS -m 10 -X POST "${ADMIN_URL}/undrain?id=${slot}" >/dev/null 2>&1 || \
+        echo "WARN: undrain af slot $slot fejlede (slot self-healer)" >&2
+}
+
+assign_slot() {
+    local slot="$1" cfg="$2"
+    drain_slot "$slot"                                  # stop trafik FØR teardown
+    ln -sfn "$POOL/$cfg" "$ACTIVE/proxy${slot}.conf"
+    systemctl restart "weircon-proxy@${slot}.service"   # river gammel ned, rejser ny
+    undrain_slot "$slot"                                # genoptag trafik EFTER (m. warmup)
+}
+
+mkdir -p "$(dirname "$STATE")"
+
+# --- init: seed alle slots distinkt -------------------------------------
+if [[ "${1:-}" == "init" ]]; then
+    pos=0
+    for (( s = 0; s < SLOTS; s++ )); do
+        if ! pick_free_config "$pos" "$s"; then
+            echo "kunne ikke finde ledig config til slot $s" >&2
+            exit 1
+        fi
+        ln -sfn "$POOL/$CHOSEN" "$ACTIVE/proxy${s}.conf"
+        pos="$NEXT_POS"
+        echo "slot $s -> $CHOSEN"
+    done
+    printf 'slot=0\npos=%s\n' "$pos" > "$STATE"
+    echo "seedet $SLOTS slots; start/genstart tunnelerne for at aktivere"
+    exit 0
+fi
+
+# --- normal: roter præcis én slot ---------------------------------------
+slot=0
+pos=0
+# shellcheck disable=SC1090
+[[ -f "$STATE" ]] && source "$STATE"
+(( slot >= SLOTS )) && slot=0
+
+if ! pick_free_config "$pos" "$slot"; then
+    echo "kunne ikke finde ledig config til slot $slot" >&2
+    exit 1
+fi
+
+assign_slot "$slot" "$CHOSEN"
+echo "roterede slot $slot -> $CHOSEN ($((slot + 1))/$SLOTS denne runde)"
+
+# Ryk cursors: næste slot, og pulje-position er allerede sat af pick_free_config.
+slot=$(( (slot + 1) % SLOTS ))
+printf 'slot=%s\npos=%s\n' "$slot" "$NEXT_POS" > "$STATE"

lxc/setup-container.sh

@@ -54,18 +54,26 @@ chmod +x "$BIN"
 # 4. Helper-scripts
 install -Dm755 "$SCRIPT_DIR/netns-up.sh"   /usr/local/sbin/weircon-netns-up
 install -Dm755 "$SCRIPT_DIR/netns-down.sh" /usr/local/sbin/weircon-netns-down
+install -Dm755 "$SCRIPT_DIR/rotate.sh"     /usr/local/sbin/weircon-rotate
 
 # 5. systemd units
 install -Dm644 "$SCRIPT_DIR/weircon-proxies.target"   /etc/systemd/system/weircon-proxies.target
 install -Dm644 "$SCRIPT_DIR/weircon-proxy@.service"   /etc/systemd/system/weircon-proxy@.service
 install -Dm644 "$SCRIPT_DIR/weircon-fetch.service"    /etc/systemd/system/weircon-fetch.service
+install -Dm644 "$SCRIPT_DIR/weircon-rotate.service"   /etc/systemd/system/weircon-rotate.service
+install -Dm644 "$SCRIPT_DIR/weircon-rotate.timer"     /etc/systemd/system/weircon-rotate.timer
 
 # 6. Config-dir + default env
-mkdir -p /etc/weircon-random-proxy/wg
-chmod 700 /etc/weircon-random-proxy/wg
+#    wg/      = aktive slot-configs (proxy0.conf..proxyN.conf, evt. symlinks)
+#    wg-pool/ = valgfri pulje af ekstra configs som rotationen cykler igennem
+mkdir -p /etc/weircon-random-proxy/wg /etc/weircon-random-proxy/wg-pool
+chmod 700 /etc/weircon-random-proxy/wg /etc/weircon-random-proxy/wg-pool
 if [[ ! -f /etc/weircon-random-proxy/fetch.env ]]; then
     install -m640 "$SCRIPT_DIR/fetch.env.example" /etc/weircon-random-proxy/fetch.env
 fi
+if [[ ! -f /etc/weircon-random-proxy/rotate.env ]]; then
+    install -m640 "$SCRIPT_DIR/rotate.env.example" /etc/weircon-random-proxy/rotate.env
+fi
 
 systemctl daemon-reload
 
@@ -89,6 +97,16 @@ Start stakken:
   systemctl enable --now weircon-proxy@{0..9}.service
   systemctl enable --now weircon-fetch.service
 
+(Valgfrit) Roter over en STØRRE pulje af configs end de 10 slots:
+  # læg fx 50-100 configs i puljen
+  cp proton-*.conf /etc/weircon-random-proxy/wg-pool/
+  # seed de 10 aktive slots som symlinks ind i puljen
+  weircon-rotate init
+  systemctl restart weircon-proxy@{0..9}.service
+  # roter automatisk én slot ad gangen (interval i weircon-rotate.timer)
+  systemctl enable --now weircon-rotate.timer
+  # juster intervallet: systemctl edit weircon-rotate.timer  (default 5min)
+
 Verificér:
   systemctl status 'weircon-proxy@*'
   curl http://127.0.0.1:8080/health

lxc/systemd/weircon-rotate.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=weircon-random-proxy: roter én tunnel-slot til næste WG-config i puljen
+After=weircon-proxies.target
+Wants=weircon-proxies.target
+
+[Service]
+Type=oneshot
+EnvironmentFile=-/etc/weircon-random-proxy/rotate.env
+ExecStart=/usr/local/sbin/weircon-rotate

lxc/systemd/weircon-rotate.timer

@@ -0,0 +1,21 @@
+[Unit]
+Description=weircon-random-proxy: periodisk slot-rotation
+PartOf=weircon-proxies.target
+
+[Timer]
+# Standard: roter én slot hvert 5. minut. Med 10 slots betyder det at hele
+# slot-sættet er cyklet igennem ca. hvert 50. minut, og hver enkelt config i
+# en pulje på N filer er brugt mindst én gang efter ca. (N * 5) minutter.
+#
+# Skift interval uden at redigere denne fil:
+#   systemctl edit weircon-rotate.timer
+# og indsæt fx:
+#   [Timer]
+#   OnUnitActiveSec=   # (tom linje nulstiller arvet værdi)
+#   OnUnitActiveSec=15min
+OnBootSec=5min
+OnUnitActiveSec=5min
+AccuracySec=15s
+
+[Install]
+WantedBy=timers.target

service/admin.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+)
+
+// newAdminHandler exposes the rotation control surface. It is intended to bind
+// to localhost only (WEIRCON_ADMIN_LISTEN) and is called by rotate.sh:
+//
+//	POST /drain?id=N    take slot N out of service; blocks until in-flight
+//	                    drains (bounded by WEIRCON_DRAIN_TIMEOUT_SEC) + settle.
+//	                    200 {"id":N,"drained":true,"inflight":0} on a clean drain,
+//	                    "drained":false with the residual count on timeout.
+//	POST /undrain?id=N  return slot N to service after the warmup window.
+//	GET  /status        snapshot of every slot.
+func newAdminHandler(cfg Config, mgr *proxyManager) http.Handler {
+	mux := http.NewServeMux()
+
+	slotID := func(w http.ResponseWriter, r *http.Request) (int, bool) {
+		raw := r.URL.Query().Get("id")
+		id, err := strconv.Atoi(raw)
+		if err != nil || id < 0 || id >= mgr.n {
+			http.Error(w, fmt.Sprintf("id must be 0-%d", mgr.n-1), http.StatusBadRequest)
+			return 0, false
+		}
+		return id, true
+	}
+	writeJSON := func(w http.ResponseWriter, v any) {
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(v)
+	}
+
+	mux.HandleFunc("/drain", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "POST only", http.StatusMethodNotAllowed)
+			return
+		}
+		id, ok := slotID(w, r)
+		if !ok {
+			return
+		}
+		residual := mgr.drain(id, cfg.DrainTimeout)
+		writeJSON(w, map[string]any{"id": id, "drained": residual == 0, "inflight": residual})
+	})
+
+	mux.HandleFunc("/undrain", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "POST only", http.StatusMethodNotAllowed)
+			return
+		}
+		id, ok := slotID(w, r)
+		if !ok {
+			return
+		}
+		mgr.undrain(id)
+		writeJSON(w, map[string]any{"id": id, "warmup_sec": int(cfg.DrainWarmup.Seconds())})
+	})
+
+	mux.HandleFunc("/status", func(w http.ResponseWriter, r *http.Request) {
+		writeJSON(w, mgr.snapshot())
+	})
+
+	return mux
+}

service/main.go

@@ -7,12 +7,12 @@
 package main
 
 import (
-	_ "embed"
 	"context"
+	_ "embed"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
-	"math/rand/v2"
 	"net"
 	"net/http"
 	"net/http/httputil"
@@ -29,17 +29,37 @@ import (
 var uiHTML []byte
 
 type Config struct {
-	Listen     string
-	ProxyAddrs []string
-	Timeout    time.Duration
-	UIEnabled  bool
+	Listen      string
+	AdminListen string
+	ProxyAddrs  []string
+	Timeout     time.Duration
+	UIEnabled   bool
+
+	// Rotation drain tuning.
+	DrainTimeout time.Duration // max wait for in-flight to clear during drain
+	DrainSettle  time.Duration // quiet period after in-flight hits zero (the "before")
+	DrainWarmup  time.Duration // post-undrain cool-in before re-selection (the "after")
+	DrainMaxHold time.Duration // safety: auto-undrain a slot if undrain never arrives
+
+	// Egress-IP prober (feeds /status).
+	ProbeURL      string        // IP-echo endpoint fetched through each tunnel
+	ProbeInterval time.Duration // 0 disables probing
+	ProbeTimeout  time.Duration // per-probe ceiling
 }
 
 func loadConfig() (Config, error) {
 	cfg := Config{
-		Listen:    envStr("WEIRCON_LISTEN", ":8080"),
-		Timeout:   time.Duration(envInt("WEIRCON_REQUEST_TIMEOUT_SEC", 30)) * time.Second,
-		UIEnabled: envBool("WEIRCON_UI_ENABLED", true),
+		Listen:        envStr("WEIRCON_LISTEN", ":8080"),
+		AdminListen:   envStr("WEIRCON_ADMIN_LISTEN", "127.0.0.1:8081"),
+		Timeout:       time.Duration(envInt("WEIRCON_REQUEST_TIMEOUT_SEC", 30)) * time.Second,
+		UIEnabled:     envBool("WEIRCON_UI_ENABLED", true),
+		DrainTimeout:  time.Duration(envInt("WEIRCON_DRAIN_TIMEOUT_SEC", 25)) * time.Second,
+		DrainSettle:   time.Duration(envInt("WEIRCON_DRAIN_SETTLE_SEC", 2)) * time.Second,
+		DrainWarmup:   time.Duration(envInt("WEIRCON_DRAIN_WARMUP_SEC", 3)) * time.Second,
+		DrainMaxHold:  time.Duration(envInt("WEIRCON_DRAIN_MAX_HOLD_SEC", 60)) * time.Second,
+		ProbeURL:      envStr("WEIRCON_PROBE_URL", "https://api.ipify.org"),
+		ProbeInterval: time.Duration(envInt("WEIRCON_PROBE_INTERVAL_SEC", 60)) * time.Second,
+		ProbeTimeout:  time.Duration(envInt("WEIRCON_PROBE_TIMEOUT_SEC", 10)) * time.Second,
 	}
 	if raw := envStr("WEIRCON_PROXY_ADDRS", ""); raw != "" {
 		for _, a := range strings.Split(raw, ",") {
@@ -192,10 +212,13 @@ func stripIdentifying(h http.Header) {
 	}
 }
 
-func pickProxyID(req *http.Request, n int) (int, error) {
+// parsePin reads the optional X-WEIRCON-PROXY-ID header. It returns (-1, nil)
+// when no pin is requested (caller should pick at random). The actual slot
+// reservation — and the draining check — happens in the manager, not here.
+func parsePin(req *http.Request, n int) (int, error) {
 	raw := req.Header.Get("X-Weircon-Proxy-Id")
 	if raw == "" {
-		return rand.IntN(n), nil
+		return -1, nil
 	}
 	id, err := strconv.Atoi(raw)
 	if err != nil {
@@ -235,7 +258,7 @@ func resolveMethod(req *http.Request) string {
 	return req.Method
 }
 
-func newHandler(cfg Config, pool []*http.Transport) http.Handler {
+func newHandler(cfg Config, pool []*http.Transport, mgr *proxyManager) http.Handler {
 	rp := &httputil.ReverseProxy{
 		Rewrite: func(pr *httputil.ProxyRequest) {
 			rc, ok := pr.In.Context().Value(ctxKey{}).(reqCtx)
@@ -271,6 +294,13 @@ func newHandler(cfg Config, pool []*http.Transport) http.Handler {
 		w.Header().Set("Content-Type", "application/json")
 		fmt.Fprintf(w, `{"ok":true,"proxies":%d}`, count)
 	})
+	// Poll-friendly status for scraper-side dashboards: per-slot egress IP +
+	// state, plus when the next rotation is due and which egress it replaces.
+	mux.HandleFunc("/status", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("Cache-Control", "no-store")
+		_ = json.NewEncoder(w).Encode(mgr.snapshot())
+	})
 	if cfg.UIEnabled {
 		mux.HandleFunc("/ui", func(w http.ResponseWriter, r *http.Request) {
 			w.Header().Set("Content-Type", "text/html; charset=utf-8")
@@ -296,11 +326,34 @@ func newHandler(cfg Config, pool []*http.Transport) http.Handler {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}
-		id, err := pickProxyID(r, count)
+		pin, err := parsePin(r, count)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}
+
+		// Reserve a slot. A pinned slot that is mid-rotation is rejected (the
+		// caller asked for that specific egress); a random pick just skips
+		// draining/warming slots. release() runs after the response finishes
+		// streaming so drain() can observe a true in-flight count.
+		var id int
+		if pin >= 0 {
+			id = pin
+			if err := mgr.acquirePinned(id); err != nil {
+				w.Header().Set("Retry-After", "5")
+				http.Error(w, err.Error(), http.StatusServiceUnavailable)
+				return
+			}
+		} else {
+			id, err = mgr.acquireAny()
+			if err != nil {
+				w.Header().Set("Retry-After", "5")
+				http.Error(w, err.Error(), http.StatusServiceUnavailable)
+				return
+			}
+		}
+		defer mgr.release(id)
+
 		ctx := context.WithValue(r.Context(), ctxKey{}, reqCtx{
 			proxyID: id,
 			target:  target,
@@ -320,9 +373,40 @@ func main() {
 	if err != nil {
 		log.Fatalf("transports: %v", err)
 	}
+	mgr := newProxyManager(len(pool), cfg.DrainSettle, cfg.DrainWarmup, cfg.DrainMaxHold)
+
+	// Background egress-IP prober feeds /status. A slot is re-probed shortly
+	// after it rotates back in so its new egress IP appears promptly rather
+	// than waiting for the next periodic pass.
+	if cfg.ProbeInterval > 0 {
+		pr := &prober{mgr: mgr, pool: pool, url: cfg.ProbeURL, timeout: cfg.ProbeTimeout}
+		mgr.afterUndrain = func(id int) {
+			time.AfterFunc(cfg.DrainWarmup+500*time.Millisecond, func() { pr.probe(id) })
+		}
+		go pr.run(context.Background(), cfg.ProbeInterval)
+		log.Printf("egress prober: %s every %s", cfg.ProbeURL, cfg.ProbeInterval)
+	}
+
+	// Admin server: localhost-only by default so drain/undrain is reachable by
+	// the rotation tooling running in the same LXC but never from the public
+	// reverse proxy. Empty WEIRCON_ADMIN_LISTEN disables it entirely.
+	if cfg.AdminListen != "" {
+		admin := &http.Server{
+			Addr:              cfg.AdminListen,
+			Handler:           newAdminHandler(cfg, mgr),
+			ReadHeaderTimeout: 10 * time.Second,
+		}
+		go func() {
+			log.Printf("admin listening on %s", cfg.AdminListen)
+			if err := admin.ListenAndServe(); err != nil {
+				log.Fatalf("admin server: %v", err)
+			}
+		}()
+	}
+
 	srv := &http.Server{
 		Addr:              cfg.Listen,
-		Handler:           newHandler(cfg, pool),
+		Handler:           newHandler(cfg, pool, mgr),
 		ReadHeaderTimeout: 10 * time.Second,
 		IdleTimeout:       120 * time.Second,
 	}

service/manager.go

@@ -0,0 +1,194 @@
+package main
+
+import (
+	"errors"
+	"math/rand/v2"
+	"sync"
+	"time"
+)
+
+// errDraining is returned when a request pins a slot that is currently being
+// rotated out. errNoProxies is returned when no slot is selectable at all.
+var (
+	errDraining  = errors.New("proxy is draining for rotation")
+	errNoProxies = errors.New("no proxy currently available")
+)
+
+// proxyManager tracks per-slot availability so the rotation tooling can take a
+// slot out of service a moment before its WireGuard tunnel is torn down and
+// bring it back a moment after the new tunnel is up — without ever handing an
+// in-flight request to a slot that is mid-rotation.
+//
+// Lifecycle of a rotation (driven by rotate.sh via the admin server):
+//
+//	drain(id)   -> stop routing NEW requests to id, block until in-flight
+//	               drains to zero (bounded by timeout) + a short settle.
+//	(restart the tunnel unit)
+//	undrain(id) -> mark id available again, but keep it out of the candidate
+//	               set for `warmup` so the fresh handshake can settle first.
+//
+// A drained slot self-heals: if undrain never arrives (e.g. rotate.sh died
+// mid-run) the slot returns to service after maxHold so the pool can't shrink
+// permanently.
+type proxyManager struct {
+	mu       sync.Mutex
+	n        int
+	inflight []int
+	draining []bool
+	warmupAt []time.Time // slot not selectable until now >= warmupAt[id]
+	healTmr  []*time.Timer
+	egress   []egressInfo // last observed egress IP per slot (from the prober)
+
+	// Rotation cadence, inferred from drain() calls. rotate.sh rotates exactly
+	// one slot per timer tick in round-robin order, so the gap between drains is
+	// the rotation interval and the next slot to rotate is (lastSlot+1) % n.
+	lastSlot    int
+	lastRotated time.Time
+	interval    time.Duration
+
+	// afterUndrain, if set, is called (outside the lock) when a slot returns to
+	// service — used by the prober to refresh that slot's egress IP promptly.
+	afterUndrain func(id int)
+
+	settle  time.Duration // quiet period after in-flight hits zero (the "before")
+	warmup  time.Duration // post-undrain cool-in before re-selection (the "after")
+	maxHold time.Duration // safety: auto-undrain if rotate.sh never calls undrain
+}
+
+// egressInfo is the prober's last view of a slot's public egress.
+type egressInfo struct {
+	ip        string
+	latency   time.Duration
+	ok        bool
+	checkedAt time.Time
+}
+
+func newProxyManager(n int, settle, warmup, maxHold time.Duration) *proxyManager {
+	return &proxyManager{
+		n:        n,
+		inflight: make([]int, n),
+		draining: make([]bool, n),
+		warmupAt: make([]time.Time, n),
+		healTmr:  make([]*time.Timer, n),
+		egress:   make([]egressInfo, n),
+		lastSlot: -1,
+		settle:   settle,
+		warmup:   warmup,
+		maxHold:  maxHold,
+	}
+}
+
+// setEgress records the prober's latest observation for a slot.
+func (m *proxyManager) setEgress(id int, ip string, latency time.Duration, ok bool) {
+	m.mu.Lock()
+	m.egress[id] = egressInfo{ip: ip, latency: latency, ok: ok, checkedAt: time.Now()}
+	m.mu.Unlock()
+}
+
+// selectableLocked reports whether slot id may take a new request right now.
+// Caller must hold m.mu.
+func (m *proxyManager) selectableLocked(id int) bool {
+	if m.draining[id] {
+		return false
+	}
+	if w := m.warmupAt[id]; !w.IsZero() && time.Now().Before(w) {
+		return false
+	}
+	return true
+}
+
+// acquirePinned reserves a specific slot for one request. It combines the
+// availability check and the in-flight increment under the lock so a drain
+// can't slip in between. Call release(id) when the request finishes.
+func (m *proxyManager) acquirePinned(id int) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if !m.selectableLocked(id) {
+		return errDraining
+	}
+	m.inflight[id]++
+	return nil
+}
+
+// acquireAny picks a random selectable slot and reserves it. Returns errNoProxies
+// if every slot is draining/warming. Call release(id) when the request finishes.
+func (m *proxyManager) acquireAny() (int, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	cands := make([]int, 0, m.n)
+	for i := 0; i < m.n; i++ {
+		if m.selectableLocked(i) {
+			cands = append(cands, i)
+		}
+	}
+	if len(cands) == 0 {
+		return 0, errNoProxies
+	}
+	id := cands[rand.IntN(len(cands))]
+	m.inflight[id]++
+	return id, nil
+}
+
+// release marks one in-flight request on id as finished.
+func (m *proxyManager) release(id int) {
+	m.mu.Lock()
+	if m.inflight[id] > 0 {
+		m.inflight[id]--
+	}
+	m.mu.Unlock()
+}
+
+// drain stops new traffic to id and waits until in-flight reaches zero (bounded
+// by timeout) followed by a settle period. Returns the number of requests still
+// in flight when it gave up (0 on a clean drain). A self-heal timer is armed so
+// the slot recovers even if undrain is never called.
+func (m *proxyManager) drain(id int, timeout time.Duration) int {
+	m.mu.Lock()
+	m.draining[id] = true
+	// Infer rotation cadence: the gap since the previous drain is the interval.
+	now := time.Now()
+	if !m.lastRotated.IsZero() {
+		if d := now.Sub(m.lastRotated); d > 0 {
+			m.interval = d
+		}
+	}
+	m.lastSlot = id
+	m.lastRotated = now
+	if m.healTmr[id] != nil {
+		m.healTmr[id].Stop()
+	}
+	m.healTmr[id] = time.AfterFunc(m.maxHold, func() { m.undrain(id) })
+	m.mu.Unlock()
+
+	deadline := time.Now().Add(timeout)
+	for {
+		m.mu.Lock()
+		inf := m.inflight[id]
+		m.mu.Unlock()
+		if inf == 0 {
+			time.Sleep(m.settle) // let the last connection's FIN flush
+			return 0
+		}
+		if time.Now().After(deadline) {
+			return inf
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+}
+
+// undrain returns id to service after a warmup window during which it stays out
+// of the candidate set (so the just-rebuilt tunnel's handshake can complete).
+func (m *proxyManager) undrain(id int) {
+	m.mu.Lock()
+	if m.healTmr[id] != nil {
+		m.healTmr[id].Stop()
+		m.healTmr[id] = nil
+	}
+	m.draining[id] = false
+	m.warmupAt[id] = time.Now().Add(m.warmup)
+	hook := m.afterUndrain
+	m.mu.Unlock()
+	if hook != nil {
+		hook(id)
+	}
+}

service/manager_test.go

@@ -0,0 +1,176 @@
+package main
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+func newTestMgr(n int) *proxyManager {
+	// Zero settle/warmup so tests don't sleep; tiny maxHold disabled by being long.
+	return newProxyManager(n, 0, 0, time.Hour)
+}
+
+func TestAcquireAnySkipsDraining(t *testing.T) {
+	m := newTestMgr(3)
+	m.drain(0, time.Second) // slot 0 out
+	m.drain(1, time.Second) // slot 1 out
+
+	// Only slot 2 should ever come back from acquireAny.
+	for i := 0; i < 50; i++ {
+		id, err := m.acquireAny()
+		if err != nil {
+			t.Fatalf("acquireAny: %v", err)
+		}
+		if id != 2 {
+			t.Fatalf("expected only slot 2 selectable, got %d", id)
+		}
+		m.release(id)
+	}
+}
+
+func TestAcquireAnyNoneAvailable(t *testing.T) {
+	m := newTestMgr(2)
+	m.drain(0, time.Second)
+	m.drain(1, time.Second)
+	if _, err := m.acquireAny(); err != errNoProxies {
+		t.Fatalf("expected errNoProxies, got %v", err)
+	}
+}
+
+func TestAcquirePinnedDraining(t *testing.T) {
+	m := newTestMgr(2)
+	if err := m.acquirePinned(1); err != nil {
+		t.Fatalf("healthy slot should acquire: %v", err)
+	}
+	m.release(1)
+
+	m.drain(1, time.Second)
+	if err := m.acquirePinned(1); err != errDraining {
+		t.Fatalf("expected errDraining for pinned drained slot, got %v", err)
+	}
+}
+
+func TestDrainWaitsForInflight(t *testing.T) {
+	m := newTestMgr(1)
+	if _, err := m.acquireAny(); err != nil { // hold slot 0 in flight
+		t.Fatal(err)
+	}
+
+	done := make(chan int, 1)
+	go func() { done <- m.drain(0, 2*time.Second) }()
+
+	// drain must not return while the request is still in flight.
+	select {
+	case <-done:
+		t.Fatal("drain returned before in-flight request released")
+	case <-time.After(150 * time.Millisecond):
+	}
+
+	m.release(0)
+	select {
+	case residual := <-done:
+		if residual != 0 {
+			t.Fatalf("expected clean drain (0 residual), got %d", residual)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("drain did not return after release")
+	}
+}
+
+func TestDrainTimeoutReportsResidual(t *testing.T) {
+	m := newTestMgr(1)
+	if _, err := m.acquireAny(); err != nil { // never released
+		t.Fatal(err)
+	}
+	if residual := m.drain(0, 100*time.Millisecond); residual != 1 {
+		t.Fatalf("expected residual 1 on timeout, got %d", residual)
+	}
+}
+
+func TestUndrainRestoresSelection(t *testing.T) {
+	m := newTestMgr(1)
+	m.drain(0, time.Second)
+	if _, err := m.acquireAny(); err != errNoProxies {
+		t.Fatalf("expected slot unavailable while draining, got %v", err)
+	}
+	m.undrain(0) // warmup is zero in test mgr → immediately selectable
+	if _, err := m.acquireAny(); err != nil {
+		t.Fatalf("expected slot available after undrain, got %v", err)
+	}
+}
+
+func TestWarmupHoldsSlotOut(t *testing.T) {
+	m := newProxyManager(1, 0, 200*time.Millisecond, time.Hour)
+	m.undrain(0) // sets warmupAt = now + 200ms
+	if _, err := m.acquireAny(); err != errNoProxies {
+		t.Fatalf("expected slot held out during warmup, got %v", err)
+	}
+	time.Sleep(250 * time.Millisecond)
+	if _, err := m.acquireAny(); err != nil {
+		t.Fatalf("expected slot available after warmup, got %v", err)
+	}
+}
+
+func TestSelfHealOnMissedUndrain(t *testing.T) {
+	m := newProxyManager(1, 0, 0, 100*time.Millisecond) // maxHold 100ms
+	m.drain(0, time.Second)
+	if _, err := m.acquireAny(); err != errNoProxies {
+		t.Fatalf("expected unavailable right after drain, got %v", err)
+	}
+	time.Sleep(200 * time.Millisecond) // self-heal timer should fire
+	if _, err := m.acquireAny(); err != nil {
+		t.Fatalf("expected self-heal to restore slot, got %v", err)
+	}
+}
+
+func TestSnapshotEgressAndRotation(t *testing.T) {
+	m := newProxyManager(3, 0, 0, time.Hour)
+	m.setEgress(2, "9.9.9.9", 12*time.Millisecond, true)
+
+	m.drain(0, time.Second) // first rotation: establishes lastRotated only
+	m.undrain(0)
+	time.Sleep(5 * time.Millisecond)
+	m.drain(1, time.Second) // second rotation: gap becomes the interval; slot 1 left draining
+
+	snap := m.snapshot()
+
+	if got := snap.Proxies[2]; got.EgressIP != "9.9.9.9" || !got.Reachable || got.CheckedAgeSec == nil {
+		t.Fatalf("egress not reflected on slot 2: %+v", got)
+	}
+	if snap.Proxies[1].State != "draining" {
+		t.Fatalf("slot 1 should be draining, got %q", snap.Proxies[1].State)
+	}
+	if snap.Rotation.LastSlot == nil || *snap.Rotation.LastSlot != 1 {
+		t.Fatalf("last_slot want 1, got %v", snap.Rotation.LastSlot)
+	}
+	if snap.Rotation.NextSlot == nil || *snap.Rotation.NextSlot != 2 {
+		t.Fatalf("next_slot want 2 (round-robin), got %v", snap.Rotation.NextSlot)
+	}
+	if snap.Rotation.NextEgressIP != "9.9.9.9" {
+		t.Fatalf("next_egress_ip want 9.9.9.9 (slot 2's IP), got %q", snap.Rotation.NextEgressIP)
+	}
+	if snap.Rotation.ETASec == nil {
+		t.Fatal("expected an ETA once cadence is known")
+	}
+}
+
+func TestConcurrentAcquireRelease(t *testing.T) {
+	m := newTestMgr(4)
+	var wg sync.WaitGroup
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if id, err := m.acquireAny(); err == nil {
+				m.release(id)
+			}
+		}()
+	}
+	wg.Wait()
+	for i := 0; i < 4; i++ {
+		if m.inflight[i] != 0 {
+			t.Fatalf("slot %d leaked in-flight count: %d", i, m.inflight[i])
+		}
+	}
+}

service/status.go

@@ -0,0 +1,167 @@
+package main
+
+import (
+	"context"
+	"io"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+)
+
+// ProxyStatus is one slot's entry in the /status snapshot.
+type ProxyStatus struct {
+	ID       int    `json:"id"`
+	State    string `json:"state"` // "live" | "draining" | "warming"
+	Inflight int    `json:"inflight"`
+	// Egress fields are populated by the background prober (omitted until the
+	// first successful probe, or when probing is disabled).
+	EgressIP      string `json:"egress_ip,omitempty"`
+	Reachable     bool   `json:"reachable"`
+	LatencyMS     int64  `json:"latency_ms,omitempty"`
+	CheckedAgeSec *int64 `json:"checked_age_sec,omitempty"`
+}
+
+// RotationStatus describes when the next rotation is due and which egress it
+// will replace. All fields are inferred from observed drain timing, so they
+// are nil until enough rotations have happened to establish the cadence.
+type RotationStatus struct {
+	NextSlot          *int   `json:"next_slot,omitempty"`
+	NextEgressIP      string `json:"next_egress_ip,omitempty"`
+	ETASec            *int64 `json:"eta_sec,omitempty"`
+	IntervalSec       *int64 `json:"interval_sec,omitempty"`
+	LastSlot          *int   `json:"last_slot,omitempty"`
+	LastRotatedAgeSec *int64 `json:"last_rotated_age_sec,omitempty"`
+}
+
+// StatusSnapshot is the JSON returned by /status — cheap to produce, safe to
+// poll every second.
+type StatusSnapshot struct {
+	Now          string         `json:"now"`
+	ProxiesTotal int            `json:"proxies_total"`
+	Available    int            `json:"available"`
+	Proxies      []ProxyStatus  `json:"proxies"`
+	Rotation     RotationStatus `json:"rotation"`
+}
+
+// snapshot builds the current status under the lock. No network I/O happens
+// here — egress data is whatever the prober last cached.
+func (m *proxyManager) snapshot() StatusSnapshot {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	now := time.Now()
+
+	snap := StatusSnapshot{
+		Now:          now.UTC().Format(time.RFC3339),
+		ProxiesTotal: m.n,
+		Proxies:      make([]ProxyStatus, m.n),
+	}
+	for i := 0; i < m.n; i++ {
+		state := "live"
+		switch {
+		case m.draining[i]:
+			state = "draining"
+		case !m.warmupAt[i].IsZero() && now.Before(m.warmupAt[i]):
+			state = "warming"
+		default:
+			snap.Available++
+		}
+		ps := ProxyStatus{ID: i, State: state, Inflight: m.inflight[i]}
+		if e := m.egress[i]; !e.checkedAt.IsZero() {
+			ps.EgressIP = e.ip
+			ps.Reachable = e.ok
+			ps.LatencyMS = e.latency.Milliseconds()
+			age := int64(now.Sub(e.checkedAt).Seconds())
+			ps.CheckedAgeSec = &age
+		}
+		snap.Proxies[i] = ps
+	}
+
+	if !m.lastRotated.IsZero() {
+		last := m.lastSlot
+		snap.Rotation.LastSlot = &last
+		lra := int64(now.Sub(m.lastRotated).Seconds())
+		snap.Rotation.LastRotatedAgeSec = &lra
+		if m.interval > 0 {
+			next := (m.lastSlot + 1) % m.n
+			isec := int64(m.interval.Seconds())
+			eta := int64(m.lastRotated.Add(m.interval).Sub(now).Seconds())
+			if eta < 0 {
+				eta = 0
+			}
+			snap.Rotation.NextSlot = &next
+			snap.Rotation.NextEgressIP = m.egress[next].ip
+			snap.Rotation.IntervalSec = &isec
+			snap.Rotation.ETASec = &eta
+		}
+	}
+	return snap
+}
+
+// prober periodically fetches each live slot's public egress IP through its own
+// SOCKS transport and caches it on the manager for /status to report.
+type prober struct {
+	mgr     *proxyManager
+	pool    []*http.Transport
+	url     string
+	timeout time.Duration
+}
+
+// probe fetches the egress IP for a single slot. A non-2xx response or a body
+// that isn't a valid IP is recorded as unreachable.
+func (p *prober) probe(id int) {
+	client := &http.Client{Transport: p.pool[id], Timeout: p.timeout}
+	req, err := http.NewRequest(http.MethodGet, p.url, nil)
+	if err != nil {
+		p.mgr.setEgress(id, "", 0, false)
+		return
+	}
+	start := time.Now()
+	resp, err := client.Do(req)
+	if err != nil {
+		p.mgr.setEgress(id, "", 0, false)
+		return
+	}
+	defer resp.Body.Close()
+	body, _ := io.ReadAll(io.LimitReader(resp.Body, 64))
+	ip := string(body)
+	for len(ip) > 0 && (ip[len(ip)-1] == '\n' || ip[len(ip)-1] == '\r' || ip[len(ip)-1] == ' ') {
+		ip = ip[:len(ip)-1]
+	}
+	ok := resp.StatusCode == http.StatusOK && net.ParseIP(ip) != nil
+	if !ok {
+		ip = ""
+	}
+	p.mgr.setEgress(id, ip, time.Since(start), ok)
+}
+
+// probeAll probes every currently selectable slot concurrently (draining and
+// warming slots are skipped — their egress is mid-change).
+func (p *prober) probeAll() {
+	var wg sync.WaitGroup
+	for i := 0; i < p.mgr.n; i++ {
+		p.mgr.mu.Lock()
+		sel := p.mgr.selectableLocked(i)
+		p.mgr.mu.Unlock()
+		if !sel {
+			continue
+		}
+		wg.Add(1)
+		go func(id int) { defer wg.Done(); p.probe(id) }(i)
+	}
+	wg.Wait()
+}
+
+func (p *prober) run(ctx context.Context, interval time.Duration) {
+	p.probeAll()
+	t := time.NewTicker(interval)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.C:
+			p.probeAll()
+		}
+	}
+}