diff --git a/audit.py b/audit.py
index 882a72f..ed5ad4b 100755
--- a/audit.py
+++ b/audit.py
@@ -859,6 +859,84 @@ def cmd_update_local(args: argparse.Namespace) -> int:
             if tool_name in updated_tool_names:
                 tools_by_name[tool_name] = updated_tool
 
+        # Multi-version tools (python@3.14, node@22, php@8.3, …) have one
+        # snapshot entry per cycle. build_legacy_snapshot/merge_for_display
+        # only emits the base-tool key, so without this block the cycle
+        # entries would stay stale after an upgrade — masking successful
+        # installs as "version unchanged" in the guide.
+        try:
+            from cli_audit.catalog import ToolCatalog
+            _catalog = ToolCatalog()
+        except Exception:
+            _catalog = None
+        if _catalog is not None:
+            for tool in tools_list:
+                if not _catalog.has_tool(tool.name):
+                    continue
+                catalog_data = _catalog.get_raw_data(tool.name)
+                mv_config = catalog_data.get("multi_version", {})
+                if not mv_config.get("enabled"):
+                    continue
+                # Reuse supported-cycle metadata from existing snapshot so this
+                # fast-path stays network-free. First full audit populates it;
+                # subsequent refreshes just re-detect local installs.
+                supported: list[dict] = []
+                for t in existing_tools:
+                    if t.get("base_tool") == tool.name and t.get("version_cycle"):
+                        supported.append({
+                            "cycle": t["version_cycle"],
+                            "latest": t.get("latest_upstream", ""),
+                            "status": t.get("lifecycle_status", "unknown"),
+                            "eol": None,
+                            "support": None,
+                            "release_date": None,
+                            "lts": False,
+                        })
+                if not supported:
+                    continue
+                detected = detect_multi_versions(tool.name, mv_config, supported)
+                for info in detected:
+                    cycle = str(info.get("cycle", ""))
+                    if not cycle:
+                        continue
+                    installed_v = info.get("installed")
+                    latest_v = info.get("latest_upstream", "")
+                    if installed_v and installed_v == latest_v:
+                        status_v = "UP-TO-DATE"
+                    elif installed_v:
+                        status_v = "OUTDATED"
+                    else:
+                        status_v = "NOT INSTALLED"
+                    method = info.get("install_method")
+                    versioned = f"{tool.name}@{cycle}"
+                    entry = dict(tools_by_name.get(versioned, {}))
+                    entry.update({
+                        "tool": versioned,
+                        "category": catalog_data.get("category", tool.name),
+                        "installed": installed_v or "",
+                        "installed_method": method,
+                        "installed_version": installed_v or "",
+                        "installed_path_selected": info.get("path"),
+                        "classification_reason_selected": (
+                            f"Detected via path analysis: {method}" if method
+                            else "No installation detected"
+                        ),
+                        "latest_upstream": latest_v,
+                        "latest_version": latest_v,
+                        "status": status_v,
+                        "is_multi_version": True,
+                        "base_tool": tool.name,
+                        "version_cycle": cycle,
+                        "lifecycle_status": info.get("status", "unknown"),
+                    })
+                    if status_v == "OUTDATED":
+                        entry["hint"] = f"Upgrade {tool.name} {cycle}: {installed_v} \u2192 {latest_v}"
+                    elif status_v == "NOT INSTALLED":
+                        entry["hint"] = f"Install {tool.name} {cycle}: check your package manager or version manager"
+                    else:
+                        entry["hint"] = ""
+                    tools_by_name[versioned] = entry
+
         # Write merged snapshot
         merged_tools = list(tools_by_name.values())
         write_snapshot(merged_tools, offline=OFFLINE_MODE)
diff --git a/cli_audit/collectors.py b/cli_audit/collectors.py
index 59c4352..166e233 100644
--- a/cli_audit/collectors.py
+++ b/cli_audit/collectors.py
@@ -11,12 +11,50 @@
 
 import json
 import logging
+import os
 import re
+import time
 import urllib.request
 from typing import Any
 
 logger = logging.getLogger(__name__)
 
+# Persistent cache for endoflife.date responses. Acts as a fallback when the
+# live API fetch fails (timeout, rate limit, network blip) so a transient
+# failure doesn't silently produce an empty supported-versions list — which
+# would cause downstream multi-version detection to skip every cycle.
+_ENDOFLIFE_CACHE_PATH = os.environ.get(
+    "CLI_AUDIT_ENDOFLIFE_CACHE",
+    os.path.join(
+        os.environ.get("XDG_CACHE_HOME") or os.path.expanduser("~/.cache"),
+        "cli-audit",
+        "endoflife.json",
+    ),
+)
+# In-process memoization, keyed by f"{product}:{max_versions}". Stays valid
+# for the lifetime of a single audit.py run.
+_endoflife_memo: dict[str, list[dict[str, Any]]] = {}
+
+
+def _load_endoflife_cache() -> dict[str, Any]:
+    try:
+        with open(_ENDOFLIFE_CACHE_PATH, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        return data if isinstance(data, dict) else {}
+    except (OSError, json.JSONDecodeError):
+        return {}
+
+
+def _save_endoflife_cache(data: dict[str, Any]) -> None:
+    try:
+        os.makedirs(os.path.dirname(_ENDOFLIFE_CACHE_PATH), exist_ok=True)
+        tmp = _ENDOFLIFE_CACHE_PATH + ".tmp"
+        with open(tmp, "w", encoding="utf-8") as f:
+            json.dump(data, f)
+        os.replace(tmp, _ENDOFLIFE_CACHE_PATH)
+    except OSError as e:
+        logger.debug(f"Failed to write endoflife cache: {e}")
+
 
 class CollectionError(Exception):
     """Raised when version collection fails."""
@@ -597,7 +635,13 @@ def collect_endoflife(
     """
     from datetime import datetime
 
+    memo_key = f"{product}:{max_versions}"
+    if memo_key in _endoflife_memo:
+        return _endoflife_memo[memo_key]
+
     today = datetime.now().strftime("%Y-%m-%d")
+    supported_versions: list[dict[str, Any]] = []
+    fetched_ok = False
 
     try:
         url = f"https://endoflife.date/api/{product}.json"
@@ -605,61 +649,77 @@ def collect_endoflife(
 
         if not isinstance(data, list):
             logger.warning(f"endoflife.date {product}: Unexpected response format")
-            return []
-
-        supported_versions = []
-
-        for entry in data:
-            cycle = entry.get("cycle", "")
-            eol = entry.get("eol")
-            support = entry.get("support")
-            latest = entry.get("latest", "")
-
-            # Determine if version is still supported
-            # eol can be False (still supported) or a date string
-            if eol is False:
-                is_supported = True
-            elif isinstance(eol, str):
-                is_supported = eol > today
-            else:
-                is_supported = False
-
-            if not is_supported:
-                continue
-
-            # Determine status: active (full support) vs security (security fixes only)
-            if support is None or support is False:
-                status = "active"
-            elif isinstance(support, str) and support > today:
-                status = "active"
-            else:
-                status = "security"
-
-            supported_versions.append({
-                "cycle": str(cycle),
-                "latest": latest,
-                "status": status,
-                "eol": eol,
-                "support": support,
-                "release_date": entry.get("releaseDate"),
-                "lts": entry.get("lts", False),
-            })
-
-            if len(supported_versions) >= max_versions:
-                break
-
-        logger.debug(f"endoflife.date {product}: Found {len(supported_versions)} supported versions")
-        return supported_versions
+        else:
+            for entry in data:
+                cycle = entry.get("cycle", "")
+                eol = entry.get("eol")
+                support = entry.get("support")
+                latest = entry.get("latest", "")
+
+                # Determine if version is still supported
+                # eol can be False (still supported) or a date string
+                if eol is False:
+                    is_supported = True
+                elif isinstance(eol, str):
+                    is_supported = eol > today
+                else:
+                    is_supported = False
+
+                if not is_supported:
+                    continue
+
+                # Determine status: active (full support) vs security (security fixes only)
+                if support is None or support is False:
+                    status = "active"
+                elif isinstance(support, str) and support > today:
+                    status = "active"
+                else:
+                    status = "security"
+
+                supported_versions.append({
+                    "cycle": str(cycle),
+                    "latest": latest,
+                    "status": status,
+                    "eol": eol,
+                    "support": support,
+                    "release_date": entry.get("releaseDate"),
+                    "lts": entry.get("lts", False),
+                })
+
+                if len(supported_versions) >= max_versions:
+                    break
+
+            fetched_ok = True
+            logger.debug(f"endoflife.date {product}: Found {len(supported_versions)} supported versions")
 
     except Exception as e:
         logger.debug(f"endoflife.date failed for {product}: {e}")
 
-    # Use offline cache if available
+    if fetched_ok:
+        _endoflife_memo[memo_key] = supported_versions
+        cache = _load_endoflife_cache()
+        cache[memo_key] = {"at": int(time.time()), "entries": supported_versions}
+        _save_endoflife_cache(cache)
+        return supported_versions
+
+    # HTTP failed (or response was malformed). Try persistent file cache next —
+    # stale data beats silently pretending the product has no supported cycles.
+    cache = _load_endoflife_cache()
+    cached = cache.get(memo_key)
+    if isinstance(cached, dict) and isinstance(cached.get("entries"), list):
+        age = int(time.time()) - int(cached.get("at", 0))
+        logger.debug(f"endoflife.date {product}: using file cache (age {age}s)")
+        _endoflife_memo[memo_key] = cached["entries"]
+        return cached["entries"]
+
+    # Legacy offline_cache argument (from write_upstream_cache dumps).
     if offline_cache and product in offline_cache:
         logger.debug(f"endoflife.date {product}: Using offline cache")
+        _endoflife_memo[memo_key] = offline_cache[product]
         return offline_cache[product]
 
     logger.warning(f"endoflife.date {product}: No versions found")
+    _endoflife_memo[memo_key] = []
     return []
 
 
diff --git a/scripts/guide.sh b/scripts/guide.sh
index a647dbb..d49b463 100755
--- a/scripts/guide.sh
+++ b/scripts/guide.sh
@@ -165,6 +165,40 @@ osc8() {
   [ -n "$url" ] && printf '\e]8;;%s\e\\%s\e]8;;\e\\' "$url" "$text" || printf '%s' "$text"
 }
 
+# Probe the installed version directly from the binary — bypasses the
+# snapshot round-trip. Used as a fallback in upgrade-success checks so a
+# stale snapshot (e.g. after a transient endoflife failure) doesn't mask a
+# genuinely successful install.
+#
+# Args: catalog_tool [version_cycle]
+# Echoes version number (e.g. "3.14.4") on success, empty on failure.
+probe_installed_version() {
+  local catalog_tool="$1"
+  local version_cycle="${2:-}"
+  local binary pattern bin_path ver
+
+  if [ -n "$version_cycle" ]; then
+    pattern="$(catalog_get_property "$catalog_tool" "multi_version.binary_pattern" 2>/dev/null)"
+    [ -z "$pattern" ] && pattern="${catalog_tool}{cycle}"
+    binary="${pattern//\{cycle\}/$version_cycle}"
+  else
+    binary="$(catalog_get_property "$catalog_tool" "binary_name" 2>/dev/null)"
+    [ -z "$binary" ] && binary="$catalog_tool"
+  fi
+
+  if [[ "$binary" == /* ]]; then
+    [ -x "$binary" ] || return 1
+    bin_path="$binary"
+  else
+    bin_path="$(command -v "$binary" 2>/dev/null)" || return 1
+  fi
+
+  # Try --version first, then -v, capture both stdout and stderr. Extract
+  # the first dotted version number we see.
+  ver="$("$bin_path" --version 2>&1 || "$bin_path" -v 2>&1 || true)"
+  printf '%s\n' "$ver" | grep -oE '[0-9]+\.[0-9]+(\.[0-9]+)?' | head -n1
+}
+
 # Print installed status line (reusable for auto-update and interactive prompts)
 print_installed_status() {
   local installed="$1"
@@ -235,7 +269,14 @@ process_tool() {
   local install_action="$(catalog_get_guide_property "$catalog_tool" install_action "")"
   local description="$(catalog_get_property "$catalog_tool" description)"
   local homepage="$(catalog_get_property "$catalog_tool" homepage)"
-  local auto_update="$(config_get_auto_update "$catalog_tool")"
+  # Multi-version tools (python@3.13, php@8.3, etc.) store auto-update per cycle,
+  # so 'a' on one cycle doesn't silently apply to other cycles. Non-multi-version
+  # tools use the bare catalog name.
+  local auto_update_key="$catalog_tool"
+  if [ -n "$is_multi_version" ]; then
+    auto_update_key="$tool"
+  fi
+  local auto_update="$(config_get_auto_update "$auto_update_key")"
 
   # Check if runtime requirements are satisfied (e.g., npm requires node)
   local missing_req
@@ -298,9 +339,10 @@ process_tool() {
     return 0
   fi
 
-  # Check if auto_update is enabled - install without prompting
-  # BUT: multi-version tools always prompt (more significant operation)
-  if [ "$auto_update" = "true" ] && [ -z "$is_multi_version" ]; then
+  # Check if auto_update is enabled - install without prompting.
+  # For multi-version tools the key is cycle-qualified (e.g. python@3.13), so
+  # each cycle opts in independently.
+  if [ "$auto_update" = "true" ]; then
     printf "\n==> %s %s [auto-update]\n" "$icon" "$display"
     print_installed_status "$installed" "$method"
     # Show target; for self-managed tools (skip_upstream) show "self-managed" instead of <unknown>
@@ -467,6 +509,16 @@ process_tool() {
 
       # Check if upgrade succeeded by comparing versions
       local new_installed="$(json_field "$tool" installed)"
+      # If the snapshot still reports the pre-install version, the refresh
+      # may have hit a transient failure (endoflife timeout, flaky audit).
+      # Probe the binary directly as a tiebreaker — it's the ground truth.
+      if [ -z "$new_installed" ] || [ "$new_installed" = "$installed" ]; then
+        local probed_y
+        probed_y="$(probe_installed_version "$catalog_tool" "$version_cycle" 2>/dev/null || true)"
+        if [ -n "$probed_y" ] && [ "$probed_y" != "$installed" ]; then
+          new_installed="$probed_y"
+        fi
+      fi
       # Check if installer flagged binary as already at target (hash match)
       local already_current_marker="/tmp/.cli-audit/${catalog_tool}.already-current"
       local binary_already_current=""
@@ -502,9 +554,10 @@ process_tool() {
       fi
       ;;
     [Aa])
-      # Install/upgrade AND enable auto-update for future (use catalog_tool for settings)
+      # Install/upgrade AND enable auto-update for future. Use the cycle-qualified
+      # key for multi-version tools so other cycles still prompt.
       printf "    Enabling auto-update for future upgrades...\n"
-      "$ROOT"/scripts/set_auto_update.sh "$catalog_tool" true >/dev/null 2>&1 || true
+      "$ROOT"/scripts/set_auto_update.sh "$auto_update_key" true >/dev/null 2>&1 || true
 
       # Handle tool-specific version environment variables
       local upgrade_success_a=0
@@ -528,6 +581,14 @@ process_tool() {
 
       # Check if upgrade succeeded
       local new_installed_a="$(json_field "$tool" installed)"
+      # Binary-probe fallback (see [Yy] branch for rationale).
+      if [ -z "$new_installed_a" ] || [ "$new_installed_a" = "$installed" ]; then
+        local probed_a
+        probed_a="$(probe_installed_version "$catalog_tool" "$version_cycle" 2>/dev/null || true)"
+        if [ -n "$probed_a" ] && [ "$probed_a" != "$installed" ]; then
+          new_installed_a="$probed_a"
+        fi
+      fi
       # Check if installer flagged binary as already at target (hash match)
       local already_current_marker_a="/tmp/.cli-audit/${catalog_tool}.already-current"
       local binary_already_current_a=""
diff --git a/scripts/set_auto_update.sh b/scripts/set_auto_update.sh
index d74a54a..5d1660a 100755
--- a/scripts/set_auto_update.sh
+++ b/scripts/set_auto_update.sh
@@ -26,10 +26,12 @@ if [ -z "$TOOL" ]; then
   exit 1
 fi
 
-# Validate tool exists in catalog
-CATALOG_FILE="$ROOT/catalog/$TOOL.json"
+# Validate tool exists in catalog (strip @cycle suffix for multi-version tools
+# like python@3.13 — the catalog file is the base tool, python.json)
+BASE_TOOL="${TOOL%%@*}"
+CATALOG_FILE="$ROOT/catalog/$BASE_TOOL.json"
 if [ ! -f "$CATALOG_FILE" ]; then
-  echo "Error: Tool '$TOOL' not found in catalog" >&2
+  echo "Error: Tool '$BASE_TOOL' not found in catalog" >&2
   exit 1
 fi