diff --git a/modules/agent-box.nix b/modules/agent-box.nix
index e95262c3..ddc598ef 100644
--- a/modules/agent-box.nix
+++ b/modules/agent-box.nix
@@ -6443,15 +6443,16 @@ fi
 # the event. Older receivers set nothing, and an entry with no config sets `{}`,
 # so both read as "no watch-level answer" and the box-wide setting stands.
 #
-# --preamble has no delivery and so no variable: the settings page asks what a
-# named TOPIC would start, so that mode reads the watch straight out of the
-# dispatch file. Same precedence either way, because the page must not advertise
-# a worker the spawn would not use.
+# --preamble and --resolved-profile have no delivery and so no variable: the
+# settings page asks what a named TOPIC would start, so both modes read the
+# watch straight out of the dispatch file. Same precedence either way,
+# because the page must not advertise a worker the spawn would not use.
 watch_profile=""
 watch_config=""
 if [ -n "''${LOCAL_WEBHOOK_SPAWN_CONFIG:-}" ]; then
   watch_config="$LOCAL_WEBHOOK_SPAWN_CONFIG"
-elif [ "''${1:-}" = "--preamble" ] && [ -n "''${2:-}" ] && [ -n "''${LOCAL_WEBHOOK_STATE_DIR:-}" ]; then
+elif { [ "''${1:-}" = "--preamble" ] || [ "''${1:-}" = "--resolved-profile" ]; } \
+     && [ -n "''${2:-}" ] && [ -n "''${LOCAL_WEBHOOK_STATE_DIR:-}" ]; then
   # Best effort, like every other read here: no file, bad JSON or no such topic
   # all mean "this watch names no profile", never a failed render.
   watch_config=$("$JQ" -r --arg t "$2" \
@@ -6488,6 +6489,12 @@ profile_problem() {
 hook_profile=""
 hook_profile_source=""
 hook_profile_ignored=""
+# Bare names alongside the prose above, for --resolved-profile (#582): a
+# consumer that wants to warn about a named-but-missing profile needs the
+# NAME, and hook_profile_ignored only ever carries it wrapped in a sentence
+# meant for a human. Names are charset-restricted by profile_problem before
+# they land here, so a plain space-joined list round-trips with no quoting.
+hook_profile_ignored_names=""
 try_profile() {
   [ -n "$1" ] || return 0
   [ -z "$hook_profile" ] || return 0
@@ -6499,6 +6506,7 @@ try_profile() {
   fi
   echo "agent-box-webhook-spawn: ignoring profile '$1' from $2 — $why" >&2
   hook_profile_ignored="''${hook_profile_ignored:+$hook_profile_ignored; }$2 — IGNORED, $why"
+  hook_profile_ignored_names="''${hook_profile_ignored_names:+$hook_profile_ignored_names }$1"
 }
 
 try_profile "$watch_profile" "this watch's own spawnConfig.profile"
@@ -6593,6 +6601,24 @@ root, running sessions keep the arguments they started with:"
 fallback."
 }
 
+# --resolved-profile TOPIC [NOTE]: print, as one JSON object, the profile a
+# match on TOPIC would actually use right now — {"profile": NAME or null,
+# "missing": [NAME, ...]} — and spawn nothing. Same resolution as a real
+# spawn and as --preamble's prose (the precedence above already ran by the
+# time this checks $1), but MACHINE-readable: the settings page needs a bare
+# name to badge a watch's row and to warn a profile delete out from under a
+# live watch (#582), and scraping that out of --preamble's sentences would
+# break every time the wording does. `missing` lists every named-but-unusable
+# profile that was tried and passed over, most specific (the watch's own)
+# first — empty when nothing was named, distinct from `profile` being null
+# for "nothing resolved, so the box default harness starts".
+if [ "''${1:-}" = "--resolved-profile" ]; then
+  "$JQ" -n --arg p "$hook_profile" --arg m "$hook_profile_ignored_names" \
+    '{profile: (if $p == "" then null else $p end),
+      missing: (if $m == "" then [] else ($m | split(" ")) end)}'
+  exit 0
+fi
+
 # --preamble TOPIC [NOTE]: print what a match on TOPIC would launch — the
 # launch command first, then the prompt — and spawn nothing. Everything a
 # delivery decides is left as a <placeholder>: the event key names the session
@@ -13661,6 +13687,77 @@ def hook_preamble(topic, note, stamp):
     return proc.stdout.strip() if proc.returncode == 0 else ""
 
 
+@functools.lru_cache(maxsize=64)
+def hook_resolved_profile(topic, note, stamp):
+    """(profile, missing) for this standing watch, right now - profile is ""
+    when nothing resolves (a match starts the box default agent), missing is
+    a tuple of every named-but-unusable profile that was tried and passed
+    over, most specific first.
+
+    A bare answer, not prose: hook_preamble's --preamble text answers the
+    same question for a human reading the fold, but a caller that wants to
+    badge a watch's row or warn a profile delete out from under a live watch
+    (#582) needs the NAME alone, and scraping it out of a sentence would
+    break every time the wording does. Same cache key as hook_preamble, for
+    the same reason - a changed env file or profiles directory has to
+    re-render both.
+    """
+    if not HOOK_SPAWN_CMD:
+        return ("", ())
+    try:
+        proc = subprocess.run(
+            [HOOK_SPAWN_CMD, "--resolved-profile", topic, note],
+            env=dict(os.environ, LOCAL_WEBHOOK_STATE_DIR=webhook_state_dir()),
+            check=False,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+    except (OSError, subprocess.SubprocessError) as exc:
+        sys.stderr.write("webhook: resolved-profile: %s\n" % exc)
+        return ("", ())
+    if proc.returncode != 0:
+        return ("", ())
+    try:
+        data = json.loads(proc.stdout)
+    except ValueError:
+        return ("", ())
+    if not isinstance(data, dict):
+        return ("", ())
+    profile = data.get("profile")
+    missing = data.get("missing")
+    return (
+        profile if isinstance(profile, str) else "",
+        tuple(m for m in missing if isinstance(m, str))
+        if isinstance(missing, list) else (),
+    )
+
+
+def profile_usage(watches):
+    """profile name -> sorted topics whose standing watch resolves to it
+    right now, explicitly or via the box-wide AGENT_BOX_HOOK_PROFILE
+    fallback (#582). What `agent-box-profile rm`/the delete route never
+    checked: a profile deleted out from under a live watch does not stop
+    that watch, it just changes which worker future events start - silently,
+    and possibly onto a more expensive one than whoever deleted it expected.
+
+    Reuses hook_resolved_profile's own cache, so a page that already renders
+    the watch list (which looks up the same answer per row) pays for this
+    once per (topic, note, stamp), not twice.
+    """
+    stamp = hook_args_stamp()
+    usage = {}
+    for entry in watches:
+        topic = str(entry.get("topic") or "")
+        if not topic:
+            continue
+        note = str(entry.get("note") or "")
+        profile, _missing = hook_resolved_profile(topic, note, stamp)
+        if profile:
+            usage.setdefault(profile, []).append(topic)
+    return {name: sorted(topics) for name, topics in usage.items()}
+
+
 def webhook_entries(data, dispatch):
     """The topic entries of a `subscriptions` payload, session or
     dispatch side, as a list of dicts."""
@@ -17081,11 +17178,20 @@ def render_effort_options(selected=""):
     return "".join(items)
 
 
-def render_profiles(profiles):
+def render_profiles(profiles, usage=None):
     """The profiles list. Each row folds open onto its launch config and its
     environment KEY NAMES — never a value, the rule `agent-box-profile show`
     and `env ls` already keep, and the one that matters most here because a
-    profile is exactly where a token ends up."""
+    profile is exactly where a token ends up.
+
+    `usage` is profile_usage(watches) (#582): a profile a standing watch
+    resolves to right now says so on its own row, not only on the watch's,
+    because the delete button lives here and the cost of pressing it by
+    mistake is a watch quietly starting the box default agent instead - no
+    error, no dropped events, just a worker nobody chose. Defaults to none
+    in use, for a caller (a unit test, mainly) that has no watch list to
+    hand and does not care."""
+    usage = usage or {}
     base = html.escape(BASE)
     rows = []
     for name in sorted(profiles):
@@ -17103,6 +17209,28 @@ def render_profiles(profiles):
         if env_keys:
             bits.append("%d custom setting%s" % (
                 len(env_keys), "" if len(env_keys) == 1 else "s"))
+        topics = usage.get(name) or []
+        watch_warn = ""
+        if topics:
+            plural = "" if len(topics) == 1 else "es"
+            bits.append("used by %d standing watch%s" % (len(topics), plural))
+            # RAW here, not html.escape()'d: this only ever reaches the
+            # confirm() dialog below, built through json.dumps() rather than
+            # hand-spliced into a quoted JS string. A webhook topic is a
+            # source:key the operator (or a hand edit of the dispatch file)
+            # chooses, and local-webhook's own key charset allows an
+            # apostrophe - html.escape() alone would leave `&#x27;` in the
+            # HTML attribute, which the BROWSER decodes back to `'` before
+            # handing the onsubmit text to the JS parser, breaking out of a
+            # hand-quoted confirm('...') string.
+            topic_list = ", ".join(topics)
+            watch_warn = (
+                " It is used by %d standing watch%s: %s. After deleting, "
+                "%s the box default agent instead."
+                % (len(topics), plural, topic_list,
+                   "that watch starts" if len(topics) == 1
+                   else "those watches start")
+            )
         # Each bit was escaped as it went in, so the join must NOT be
         # escaped again: a MODEL holding "&" or "<" would render as visible
         # entity text ("&amp;lt;").
@@ -17131,14 +17259,26 @@ def render_profiles(profiles):
         # stored, so an edit is an edit and not a retype. SYSTEM_PROMPT is a
         # textarea for the same reason it is one above — it can span lines.
         prompt_val = html.escape(res.get("SYSTEM_PROMPT") or "")
+        # json.dumps(), not hand-quoted JS: `name` is charset-restricted
+        # (PROFILE_NAME_RE), but watch_warn's topic names are not, so this is
+        # where the confirm() dialog's whole message gets ONE correct
+        # escaping instead of a second, wrong one — html.escape() on its own
+        # protects the HTML attribute but leaves the JS string quoting to
+        # hope, and a topic holding an apostrophe broke out of it.
+        confirm_js = html.escape(
+            json.dumps(
+                "Delete profile %s?%s Sessions already running keep what "
+                "they started with." % (name, watch_warn)
+            ),
+            quote=True,
+        )
         rows.append(
             f'<li class="foldrow prof-row"><details><summary>'
             f'<span class="nm"><code>{safe}</code></span>'
             f'<span class="meta">{meta}</span>'
             f'<span class="acts"><form class="inline" method="post" '
             f'action="{base}/profiles/delete" '
-            f'onsubmit="return confirm(\'Delete profile {safe}? Sessions already '
-            f'running keep what they started with.\');">'
+            f'onsubmit="return confirm({confirm_js});">'
             f'<input type="hidden" name="name" value="{safe}">'
             f'<button type="submit" class="icon idanger" aria-label="Delete" '
             f'title="Delete profile {safe}">{ICON_TRASH}</button></form></span>'
@@ -17621,6 +17761,20 @@ def render_webhook_endpoint():
     )
 
 
+def display_hook_profile(profile, missing):
+    """The one-line answer to "what does this watch start" (#582), for the
+    row itself rather than the fold an operator has to open to find it.
+    `missing` being non-empty even when `profile` resolved is exactly the
+    case --preamble already reports via IGNORED - the watch's own name was
+    unusable and a less specific one took over - so it says so here too,
+    rather than only in the fold's prose."""
+    bit = ("Profile: %s" % profile if profile
+           else "No profile - box default agent")
+    if missing:
+        bit += " (%s not found)" % ", ".join("'%s'" % m for m in missing)
+    return bit
+
+
 def render_webhooks(watches):
     """The standing watches. Session subscriptions are NOT here: they
     belong to a session and are folded into its row above. A standing
@@ -17641,9 +17795,11 @@ def render_webhooks(watches):
             continue
         note = str(entry.get("note") or "")
         prompt = hook_preamble(topic, note, stamp)
+        profile, missing = hook_resolved_profile(topic, note, stamp)
         rows.append(render_webhook_row(
             topic,
-            [display_event_expiry(entry.get("expiresIn"))],
+            [display_event_expiry(entry.get("expiresIn")),
+             display_hook_profile(profile, missing)],
             # Only when the prompt could not be rendered: then the note is
             # the one thing left that says why this watch exists.
             "" if prompt else note,
@@ -18105,6 +18261,11 @@ def render_page(message="", kind="ok"):
     # and the panel below it — the same rule the subscription pass above
     # states, for the same reason.
     profiles = read_profiles()
+    # Which of those profiles a standing watch is actually spending right
+    # now (#582) - computed once here, from the same `watches` the webhooks
+    # panel below already walks, so the profiles panel's delete warning and
+    # that panel's per-row badge never disagree about what "in use" means.
+    usage = profile_usage(watches)
     return (
         render_head("Settings &mdash; " + html.escape(USER))
         + STYLE
@@ -18121,7 +18282,7 @@ def render_page(message="", kind="ok"):
                 base=html.escape(BASE),
                 harnesses=render_harness_options(),
                 effort=render_effort_options(),
-                profiles=render_profiles(profiles),
+                profiles=render_profiles(profiles, usage),
             ),
             webhooks_section=(
                 WEBHOOK_UNAVAILABLE_TPL.format(text=unavailable)
diff --git a/modules/src/settings-daemon.py b/modules/src/settings-daemon.py
index 7fcbdcde..4fa0e319 100644
--- a/modules/src/settings-daemon.py
+++ b/modules/src/settings-daemon.py
@@ -1547,6 +1547,77 @@ def hook_preamble(topic, note, stamp):
     return proc.stdout.strip() if proc.returncode == 0 else ""
 
 
+@functools.lru_cache(maxsize=64)
+def hook_resolved_profile(topic, note, stamp):
+    """(profile, missing) for this standing watch, right now - profile is ""
+    when nothing resolves (a match starts the box default agent), missing is
+    a tuple of every named-but-unusable profile that was tried and passed
+    over, most specific first.
+
+    A bare answer, not prose: hook_preamble's --preamble text answers the
+    same question for a human reading the fold, but a caller that wants to
+    badge a watch's row or warn a profile delete out from under a live watch
+    (#582) needs the NAME alone, and scraping it out of a sentence would
+    break every time the wording does. Same cache key as hook_preamble, for
+    the same reason - a changed env file or profiles directory has to
+    re-render both.
+    """
+    if not HOOK_SPAWN_CMD:
+        return ("", ())
+    try:
+        proc = subprocess.run(
+            [HOOK_SPAWN_CMD, "--resolved-profile", topic, note],
+            env=dict(os.environ, LOCAL_WEBHOOK_STATE_DIR=webhook_state_dir()),
+            check=False,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+    except (OSError, subprocess.SubprocessError) as exc:
+        sys.stderr.write("webhook: resolved-profile: %s\n" % exc)
+        return ("", ())
+    if proc.returncode != 0:
+        return ("", ())
+    try:
+        data = json.loads(proc.stdout)
+    except ValueError:
+        return ("", ())
+    if not isinstance(data, dict):
+        return ("", ())
+    profile = data.get("profile")
+    missing = data.get("missing")
+    return (
+        profile if isinstance(profile, str) else "",
+        tuple(m for m in missing if isinstance(m, str))
+        if isinstance(missing, list) else (),
+    )
+
+
+def profile_usage(watches):
+    """profile name -> sorted topics whose standing watch resolves to it
+    right now, explicitly or via the box-wide AGENT_BOX_HOOK_PROFILE
+    fallback (#582). What `agent-box-profile rm`/the delete route never
+    checked: a profile deleted out from under a live watch does not stop
+    that watch, it just changes which worker future events start - silently,
+    and possibly onto a more expensive one than whoever deleted it expected.
+
+    Reuses hook_resolved_profile's own cache, so a page that already renders
+    the watch list (which looks up the same answer per row) pays for this
+    once per (topic, note, stamp), not twice.
+    """
+    stamp = hook_args_stamp()
+    usage = {}
+    for entry in watches:
+        topic = str(entry.get("topic") or "")
+        if not topic:
+            continue
+        note = str(entry.get("note") or "")
+        profile, _missing = hook_resolved_profile(topic, note, stamp)
+        if profile:
+            usage.setdefault(profile, []).append(topic)
+    return {name: sorted(topics) for name, topics in usage.items()}
+
+
 def webhook_entries(data, dispatch):
     """The topic entries of a `subscriptions` payload, session or
     dispatch side, as a list of dicts."""
@@ -3528,11 +3599,20 @@ def render_effort_options(selected=""):
     return "".join(items)
 
 
-def render_profiles(profiles):
+def render_profiles(profiles, usage=None):
     """The profiles list. Each row folds open onto its launch config and its
     environment KEY NAMES — never a value, the rule `agent-box-profile show`
     and `env ls` already keep, and the one that matters most here because a
-    profile is exactly where a token ends up."""
+    profile is exactly where a token ends up.
+
+    `usage` is profile_usage(watches) (#582): a profile a standing watch
+    resolves to right now says so on its own row, not only on the watch's,
+    because the delete button lives here and the cost of pressing it by
+    mistake is a watch quietly starting the box default agent instead - no
+    error, no dropped events, just a worker nobody chose. Defaults to none
+    in use, for a caller (a unit test, mainly) that has no watch list to
+    hand and does not care."""
+    usage = usage or {}
     base = html.escape(BASE)
     rows = []
     for name in sorted(profiles):
@@ -3550,6 +3630,28 @@ def render_profiles(profiles):
         if env_keys:
             bits.append("%d custom setting%s" % (
                 len(env_keys), "" if len(env_keys) == 1 else "s"))
+        topics = usage.get(name) or []
+        watch_warn = ""
+        if topics:
+            plural = "" if len(topics) == 1 else "es"
+            bits.append("used by %d standing watch%s" % (len(topics), plural))
+            # RAW here, not html.escape()'d: this only ever reaches the
+            # confirm() dialog below, built through json.dumps() rather than
+            # hand-spliced into a quoted JS string. A webhook topic is a
+            # source:key the operator (or a hand edit of the dispatch file)
+            # chooses, and local-webhook's own key charset allows an
+            # apostrophe - html.escape() alone would leave `&#x27;` in the
+            # HTML attribute, which the BROWSER decodes back to `'` before
+            # handing the onsubmit text to the JS parser, breaking out of a
+            # hand-quoted confirm('...') string.
+            topic_list = ", ".join(topics)
+            watch_warn = (
+                " It is used by %d standing watch%s: %s. After deleting, "
+                "%s the box default agent instead."
+                % (len(topics), plural, topic_list,
+                   "that watch starts" if len(topics) == 1
+                   else "those watches start")
+            )
         # Each bit was escaped as it went in, so the join must NOT be
         # escaped again: a MODEL holding "&" or "<" would render as visible
         # entity text ("&amp;lt;").
@@ -3578,14 +3680,26 @@ def render_profiles(profiles):
         # stored, so an edit is an edit and not a retype. SYSTEM_PROMPT is a
         # textarea for the same reason it is one above — it can span lines.
         prompt_val = html.escape(res.get("SYSTEM_PROMPT") or "")
+        # json.dumps(), not hand-quoted JS: `name` is charset-restricted
+        # (PROFILE_NAME_RE), but watch_warn's topic names are not, so this is
+        # where the confirm() dialog's whole message gets ONE correct
+        # escaping instead of a second, wrong one — html.escape() on its own
+        # protects the HTML attribute but leaves the JS string quoting to
+        # hope, and a topic holding an apostrophe broke out of it.
+        confirm_js = html.escape(
+            json.dumps(
+                "Delete profile %s?%s Sessions already running keep what "
+                "they started with." % (name, watch_warn)
+            ),
+            quote=True,
+        )
         rows.append(
             f'<li class="foldrow prof-row"><details><summary>'
             f'<span class="nm"><code>{safe}</code></span>'
             f'<span class="meta">{meta}</span>'
             f'<span class="acts"><form class="inline" method="post" '
             f'action="{base}/profiles/delete" '
-            f'onsubmit="return confirm(\'Delete profile {safe}? Sessions already '
-            f'running keep what they started with.\');">'
+            f'onsubmit="return confirm({confirm_js});">'
             f'<input type="hidden" name="name" value="{safe}">'
             f'<button type="submit" class="icon idanger" aria-label="Delete" '
             f'title="Delete profile {safe}">{ICON_TRASH}</button></form></span>'
@@ -4068,6 +4182,20 @@ def render_webhook_endpoint():
     )
 
 
+def display_hook_profile(profile, missing):
+    """The one-line answer to "what does this watch start" (#582), for the
+    row itself rather than the fold an operator has to open to find it.
+    `missing` being non-empty even when `profile` resolved is exactly the
+    case --preamble already reports via IGNORED - the watch's own name was
+    unusable and a less specific one took over - so it says so here too,
+    rather than only in the fold's prose."""
+    bit = ("Profile: %s" % profile if profile
+           else "No profile - box default agent")
+    if missing:
+        bit += " (%s not found)" % ", ".join("'%s'" % m for m in missing)
+    return bit
+
+
 def render_webhooks(watches):
     """The standing watches. Session subscriptions are NOT here: they
     belong to a session and are folded into its row above. A standing
@@ -4088,9 +4216,11 @@ def render_webhooks(watches):
             continue
         note = str(entry.get("note") or "")
         prompt = hook_preamble(topic, note, stamp)
+        profile, missing = hook_resolved_profile(topic, note, stamp)
         rows.append(render_webhook_row(
             topic,
-            [display_event_expiry(entry.get("expiresIn"))],
+            [display_event_expiry(entry.get("expiresIn")),
+             display_hook_profile(profile, missing)],
             # Only when the prompt could not be rendered: then the note is
             # the one thing left that says why this watch exists.
             "" if prompt else note,
@@ -4552,6 +4682,11 @@ def render_page(message="", kind="ok"):
     # and the panel below it — the same rule the subscription pass above
     # states, for the same reason.
     profiles = read_profiles()
+    # Which of those profiles a standing watch is actually spending right
+    # now (#582) - computed once here, from the same `watches` the webhooks
+    # panel below already walks, so the profiles panel's delete warning and
+    # that panel's per-row badge never disagree about what "in use" means.
+    usage = profile_usage(watches)
     return (
         render_head("Settings &mdash; " + html.escape(USER))
         + STYLE
@@ -4568,7 +4703,7 @@ def render_page(message="", kind="ok"):
                 base=html.escape(BASE),
                 harnesses=render_harness_options(),
                 effort=render_effort_options(),
-                profiles=render_profiles(profiles),
+                profiles=render_profiles(profiles, usage),
             ),
             webhooks_section=(
                 WEBHOOK_UNAVAILABLE_TPL.format(text=unavailable)
diff --git a/modules/src/webhook-spawn.sh b/modules/src/webhook-spawn.sh
index 8010ba55..5df25b14 100644
--- a/modules/src/webhook-spawn.sh
+++ b/modules/src/webhook-spawn.sh
@@ -215,15 +215,16 @@ fi
 # the event. Older receivers set nothing, and an entry with no config sets `{}`,
 # so both read as "no watch-level answer" and the box-wide setting stands.
 #
-# --preamble has no delivery and so no variable: the settings page asks what a
-# named TOPIC would start, so that mode reads the watch straight out of the
-# dispatch file. Same precedence either way, because the page must not advertise
-# a worker the spawn would not use.
+# --preamble and --resolved-profile have no delivery and so no variable: the
+# settings page asks what a named TOPIC would start, so both modes read the
+# watch straight out of the dispatch file. Same precedence either way,
+# because the page must not advertise a worker the spawn would not use.
 watch_profile=""
 watch_config=""
 if [ -n "${LOCAL_WEBHOOK_SPAWN_CONFIG:-}" ]; then
   watch_config="$LOCAL_WEBHOOK_SPAWN_CONFIG"
-elif [ "${1:-}" = "--preamble" ] && [ -n "${2:-}" ] && [ -n "${LOCAL_WEBHOOK_STATE_DIR:-}" ]; then
+elif { [ "${1:-}" = "--preamble" ] || [ "${1:-}" = "--resolved-profile" ]; } \
+     && [ -n "${2:-}" ] && [ -n "${LOCAL_WEBHOOK_STATE_DIR:-}" ]; then
   # Best effort, like every other read here: no file, bad JSON or no such topic
   # all mean "this watch names no profile", never a failed render.
   watch_config=$("$JQ" -r --arg t "$2" \
@@ -260,6 +261,12 @@ profile_problem() {
 hook_profile=""
 hook_profile_source=""
 hook_profile_ignored=""
+# Bare names alongside the prose above, for --resolved-profile (#582): a
+# consumer that wants to warn about a named-but-missing profile needs the
+# NAME, and hook_profile_ignored only ever carries it wrapped in a sentence
+# meant for a human. Names are charset-restricted by profile_problem before
+# they land here, so a plain space-joined list round-trips with no quoting.
+hook_profile_ignored_names=""
 try_profile() {
   [ -n "$1" ] || return 0
   [ -z "$hook_profile" ] || return 0
@@ -271,6 +278,7 @@ try_profile() {
   fi
   echo "agent-box-webhook-spawn: ignoring profile '$1' from $2 — $why" >&2
   hook_profile_ignored="${hook_profile_ignored:+$hook_profile_ignored; }$2 — IGNORED, $why"
+  hook_profile_ignored_names="${hook_profile_ignored_names:+$hook_profile_ignored_names }$1"
 }
 
 try_profile "$watch_profile" "this watch's own spawnConfig.profile"
@@ -365,6 +373,24 @@ ${AGENT_BOX_HOOK_ARGS_OPTION_NAME:-the fleet-wide default}, which is the \
 fallback."
 }
 
+# --resolved-profile TOPIC [NOTE]: print, as one JSON object, the profile a
+# match on TOPIC would actually use right now — {"profile": NAME or null,
+# "missing": [NAME, ...]} — and spawn nothing. Same resolution as a real
+# spawn and as --preamble's prose (the precedence above already ran by the
+# time this checks $1), but MACHINE-readable: the settings page needs a bare
+# name to badge a watch's row and to warn a profile delete out from under a
+# live watch (#582), and scraping that out of --preamble's sentences would
+# break every time the wording does. `missing` lists every named-but-unusable
+# profile that was tried and passed over, most specific (the watch's own)
+# first — empty when nothing was named, distinct from `profile` being null
+# for "nothing resolved, so the box default harness starts".
+if [ "${1:-}" = "--resolved-profile" ]; then
+  "$JQ" -n --arg p "$hook_profile" --arg m "$hook_profile_ignored_names" \
+    '{profile: (if $p == "" then null else $p end),
+      missing: (if $m == "" then [] else ($m | split(" ")) end)}'
+  exit 0
+fi
+
 # --preamble TOPIC [NOTE]: print what a match on TOPIC would launch — the
 # launch command first, then the prompt — and spawn nothing. Everything a
 # delivery decides is left as a <placeholder>: the event key names the session
diff --git a/tests/golden/web/payloads/agent-box-settings/bin/agent-box-settings b/tests/golden/web/payloads/agent-box-settings/bin/agent-box-settings
index 40b4035b..5b85c00e 100644
--- a/tests/golden/web/payloads/agent-box-settings/bin/agent-box-settings
+++ b/tests/golden/web/payloads/agent-box-settings/bin/agent-box-settings
@@ -1879,6 +1879,77 @@ def hook_preamble(topic, note, stamp):
     return proc.stdout.strip() if proc.returncode == 0 else ""
 
 
+@functools.lru_cache(maxsize=64)
+def hook_resolved_profile(topic, note, stamp):
+    """(profile, missing) for this standing watch, right now - profile is ""
+    when nothing resolves (a match starts the box default agent), missing is
+    a tuple of every named-but-unusable profile that was tried and passed
+    over, most specific first.
+
+    A bare answer, not prose: hook_preamble's --preamble text answers the
+    same question for a human reading the fold, but a caller that wants to
+    badge a watch's row or warn a profile delete out from under a live watch
+    (#582) needs the NAME alone, and scraping it out of a sentence would
+    break every time the wording does. Same cache key as hook_preamble, for
+    the same reason - a changed env file or profiles directory has to
+    re-render both.
+    """
+    if not HOOK_SPAWN_CMD:
+        return ("", ())
+    try:
+        proc = subprocess.run(
+            [HOOK_SPAWN_CMD, "--resolved-profile", topic, note],
+            env=dict(os.environ, LOCAL_WEBHOOK_STATE_DIR=webhook_state_dir()),
+            check=False,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+    except (OSError, subprocess.SubprocessError) as exc:
+        sys.stderr.write("webhook: resolved-profile: %s\n" % exc)
+        return ("", ())
+    if proc.returncode != 0:
+        return ("", ())
+    try:
+        data = json.loads(proc.stdout)
+    except ValueError:
+        return ("", ())
+    if not isinstance(data, dict):
+        return ("", ())
+    profile = data.get("profile")
+    missing = data.get("missing")
+    return (
+        profile if isinstance(profile, str) else "",
+        tuple(m for m in missing if isinstance(m, str))
+        if isinstance(missing, list) else (),
+    )
+
+
+def profile_usage(watches):
+    """profile name -> sorted topics whose standing watch resolves to it
+    right now, explicitly or via the box-wide AGENT_BOX_HOOK_PROFILE
+    fallback (#582). What `agent-box-profile rm`/the delete route never
+    checked: a profile deleted out from under a live watch does not stop
+    that watch, it just changes which worker future events start - silently,
+    and possibly onto a more expensive one than whoever deleted it expected.
+
+    Reuses hook_resolved_profile's own cache, so a page that already renders
+    the watch list (which looks up the same answer per row) pays for this
+    once per (topic, note, stamp), not twice.
+    """
+    stamp = hook_args_stamp()
+    usage = {}
+    for entry in watches:
+        topic = str(entry.get("topic") or "")
+        if not topic:
+            continue
+        note = str(entry.get("note") or "")
+        profile, _missing = hook_resolved_profile(topic, note, stamp)
+        if profile:
+            usage.setdefault(profile, []).append(topic)
+    return {name: sorted(topics) for name, topics in usage.items()}
+
+
 def webhook_entries(data, dispatch):
     """The topic entries of a `subscriptions` payload, session or
     dispatch side, as a list of dicts."""
@@ -5299,11 +5370,20 @@ def render_effort_options(selected=""):
     return "".join(items)
 
 
-def render_profiles(profiles):
+def render_profiles(profiles, usage=None):
     """The profiles list. Each row folds open onto its launch config and its
     environment KEY NAMES — never a value, the rule `agent-box-profile show`
     and `env ls` already keep, and the one that matters most here because a
-    profile is exactly where a token ends up."""
+    profile is exactly where a token ends up.
+
+    `usage` is profile_usage(watches) (#582): a profile a standing watch
+    resolves to right now says so on its own row, not only on the watch's,
+    because the delete button lives here and the cost of pressing it by
+    mistake is a watch quietly starting the box default agent instead - no
+    error, no dropped events, just a worker nobody chose. Defaults to none
+    in use, for a caller (a unit test, mainly) that has no watch list to
+    hand and does not care."""
+    usage = usage or {}
     base = html.escape(BASE)
     rows = []
     for name in sorted(profiles):
@@ -5321,6 +5401,28 @@ def render_profiles(profiles):
         if env_keys:
             bits.append("%d custom setting%s" % (
                 len(env_keys), "" if len(env_keys) == 1 else "s"))
+        topics = usage.get(name) or []
+        watch_warn = ""
+        if topics:
+            plural = "" if len(topics) == 1 else "es"
+            bits.append("used by %d standing watch%s" % (len(topics), plural))
+            # RAW here, not html.escape()'d: this only ever reaches the
+            # confirm() dialog below, built through json.dumps() rather than
+            # hand-spliced into a quoted JS string. A webhook topic is a
+            # source:key the operator (or a hand edit of the dispatch file)
+            # chooses, and local-webhook's own key charset allows an
+            # apostrophe - html.escape() alone would leave `&#x27;` in the
+            # HTML attribute, which the BROWSER decodes back to `'` before
+            # handing the onsubmit text to the JS parser, breaking out of a
+            # hand-quoted confirm('...') string.
+            topic_list = ", ".join(topics)
+            watch_warn = (
+                " It is used by %d standing watch%s: %s. After deleting, "
+                "%s the box default agent instead."
+                % (len(topics), plural, topic_list,
+                   "that watch starts" if len(topics) == 1
+                   else "those watches start")
+            )
         # Each bit was escaped as it went in, so the join must NOT be
         # escaped again: a MODEL holding "&" or "<" would render as visible
         # entity text ("&amp;lt;").
@@ -5349,14 +5451,26 @@ def render_profiles(profiles):
         # stored, so an edit is an edit and not a retype. SYSTEM_PROMPT is a
         # textarea for the same reason it is one above — it can span lines.
         prompt_val = html.escape(res.get("SYSTEM_PROMPT") or "")
+        # json.dumps(), not hand-quoted JS: `name` is charset-restricted
+        # (PROFILE_NAME_RE), but watch_warn's topic names are not, so this is
+        # where the confirm() dialog's whole message gets ONE correct
+        # escaping instead of a second, wrong one — html.escape() on its own
+        # protects the HTML attribute but leaves the JS string quoting to
+        # hope, and a topic holding an apostrophe broke out of it.
+        confirm_js = html.escape(
+            json.dumps(
+                "Delete profile %s?%s Sessions already running keep what "
+                "they started with." % (name, watch_warn)
+            ),
+            quote=True,
+        )
         rows.append(
             f'<li class="foldrow prof-row"><details><summary>'
             f'<span class="nm"><code>{safe}</code></span>'
             f'<span class="meta">{meta}</span>'
             f'<span class="acts"><form class="inline" method="post" '
             f'action="{base}/profiles/delete" '
-            f'onsubmit="return confirm(\'Delete profile {safe}? Sessions already '
-            f'running keep what they started with.\');">'
+            f'onsubmit="return confirm({confirm_js});">'
             f'<input type="hidden" name="name" value="{safe}">'
             f'<button type="submit" class="icon idanger" aria-label="Delete" '
             f'title="Delete profile {safe}">{ICON_TRASH}</button></form></span>'
@@ -5839,6 +5953,20 @@ def render_webhook_endpoint():
     )
 
 
+def display_hook_profile(profile, missing):
+    """The one-line answer to "what does this watch start" (#582), for the
+    row itself rather than the fold an operator has to open to find it.
+    `missing` being non-empty even when `profile` resolved is exactly the
+    case --preamble already reports via IGNORED - the watch's own name was
+    unusable and a less specific one took over - so it says so here too,
+    rather than only in the fold's prose."""
+    bit = ("Profile: %s" % profile if profile
+           else "No profile - box default agent")
+    if missing:
+        bit += " (%s not found)" % ", ".join("'%s'" % m for m in missing)
+    return bit
+
+
 def render_webhooks(watches):
     """The standing watches. Session subscriptions are NOT here: they
     belong to a session and are folded into its row above. A standing
@@ -5859,9 +5987,11 @@ def render_webhooks(watches):
             continue
         note = str(entry.get("note") or "")
         prompt = hook_preamble(topic, note, stamp)
+        profile, missing = hook_resolved_profile(topic, note, stamp)
         rows.append(render_webhook_row(
             topic,
-            [display_event_expiry(entry.get("expiresIn"))],
+            [display_event_expiry(entry.get("expiresIn")),
+             display_hook_profile(profile, missing)],
             # Only when the prompt could not be rendered: then the note is
             # the one thing left that says why this watch exists.
             "" if prompt else note,
@@ -6323,6 +6453,11 @@ def render_page(message="", kind="ok"):
     # and the panel below it — the same rule the subscription pass above
     # states, for the same reason.
     profiles = read_profiles()
+    # Which of those profiles a standing watch is actually spending right
+    # now (#582) - computed once here, from the same `watches` the webhooks
+    # panel below already walks, so the profiles panel's delete warning and
+    # that panel's per-row badge never disagree about what "in use" means.
+    usage = profile_usage(watches)
     return (
         render_head("Settings &mdash; " + html.escape(USER))
         + STYLE
@@ -6339,7 +6474,7 @@ def render_page(message="", kind="ok"):
                 base=html.escape(BASE),
                 harnesses=render_harness_options(),
                 effort=render_effort_options(),
-                profiles=render_profiles(profiles),
+                profiles=render_profiles(profiles, usage),
             ),
             webhooks_section=(
                 WEBHOOK_UNAVAILABLE_TPL.format(text=unavailable)
diff --git a/tests/golden/web/payloads/agent-box-webhook-spawn/bin/agent-box-webhook-spawn b/tests/golden/web/payloads/agent-box-webhook-spawn/bin/agent-box-webhook-spawn
index 1724e5dd..d2841cc6 100644
--- a/tests/golden/web/payloads/agent-box-webhook-spawn/bin/agent-box-webhook-spawn
+++ b/tests/golden/web/payloads/agent-box-webhook-spawn/bin/agent-box-webhook-spawn
@@ -701,15 +701,16 @@ fi
 # the event. Older receivers set nothing, and an entry with no config sets `{}`,
 # so both read as "no watch-level answer" and the box-wide setting stands.
 #
-# --preamble has no delivery and so no variable: the settings page asks what a
-# named TOPIC would start, so that mode reads the watch straight out of the
-# dispatch file. Same precedence either way, because the page must not advertise
-# a worker the spawn would not use.
+# --preamble and --resolved-profile have no delivery and so no variable: the
+# settings page asks what a named TOPIC would start, so both modes read the
+# watch straight out of the dispatch file. Same precedence either way,
+# because the page must not advertise a worker the spawn would not use.
 watch_profile=""
 watch_config=""
 if [ -n "${LOCAL_WEBHOOK_SPAWN_CONFIG:-}" ]; then
   watch_config="$LOCAL_WEBHOOK_SPAWN_CONFIG"
-elif [ "${1:-}" = "--preamble" ] && [ -n "${2:-}" ] && [ -n "${LOCAL_WEBHOOK_STATE_DIR:-}" ]; then
+elif { [ "${1:-}" = "--preamble" ] || [ "${1:-}" = "--resolved-profile" ]; } \
+     && [ -n "${2:-}" ] && [ -n "${LOCAL_WEBHOOK_STATE_DIR:-}" ]; then
   # Best effort, like every other read here: no file, bad JSON or no such topic
   # all mean "this watch names no profile", never a failed render.
   watch_config=$("$JQ" -r --arg t "$2" \
@@ -746,6 +747,12 @@ profile_problem() {
 hook_profile=""
 hook_profile_source=""
 hook_profile_ignored=""
+# Bare names alongside the prose above, for --resolved-profile (#582): a
+# consumer that wants to warn about a named-but-missing profile needs the
+# NAME, and hook_profile_ignored only ever carries it wrapped in a sentence
+# meant for a human. Names are charset-restricted by profile_problem before
+# they land here, so a plain space-joined list round-trips with no quoting.
+hook_profile_ignored_names=""
 try_profile() {
   [ -n "$1" ] || return 0
   [ -z "$hook_profile" ] || return 0
@@ -757,6 +764,7 @@ try_profile() {
   fi
   echo "agent-box-webhook-spawn: ignoring profile '$1' from $2 — $why" >&2
   hook_profile_ignored="${hook_profile_ignored:+$hook_profile_ignored; }$2 — IGNORED, $why"
+  hook_profile_ignored_names="${hook_profile_ignored_names:+$hook_profile_ignored_names }$1"
 }
 
 try_profile "$watch_profile" "this watch's own spawnConfig.profile"
@@ -851,6 +859,24 @@ ${AGENT_BOX_HOOK_ARGS_OPTION_NAME:-the fleet-wide default}, which is the \
 fallback."
 }
 
+# --resolved-profile TOPIC [NOTE]: print, as one JSON object, the profile a
+# match on TOPIC would actually use right now — {"profile": NAME or null,
+# "missing": [NAME, ...]} — and spawn nothing. Same resolution as a real
+# spawn and as --preamble's prose (the precedence above already ran by the
+# time this checks $1), but MACHINE-readable: the settings page needs a bare
+# name to badge a watch's row and to warn a profile delete out from under a
+# live watch (#582), and scraping that out of --preamble's sentences would
+# break every time the wording does. `missing` lists every named-but-unusable
+# profile that was tried and passed over, most specific (the watch's own)
+# first — empty when nothing was named, distinct from `profile` being null
+# for "nothing resolved, so the box default harness starts".
+if [ "${1:-}" = "--resolved-profile" ]; then
+  "$JQ" -n --arg p "$hook_profile" --arg m "$hook_profile_ignored_names" \
+    '{profile: (if $p == "" then null else $p end),
+      missing: (if $m == "" then [] else ($m | split(" ")) end)}'
+  exit 0
+fi
+
 # --preamble TOPIC [NOTE]: print what a match on TOPIC would launch — the
 # launch command first, then the prompt — and spawn nothing. Everything a
 # delivery decides is left as a <placeholder>: the event key names the session
diff --git a/tests/webhook.nix b/tests/webhook.nix
index 8d42e55d..e02538f3 100644
--- a/tests/webhook.nix
+++ b/tests/webhook.nix
@@ -1241,6 +1241,18 @@
         f" {spawn_cmd} --preamble 'github:defangdevs/*'"
     )
     assert "IGNORED, no such profile" in launch, launch
+    # ...and --resolved-profile says the same thing with no prose to parse:
+    # nothing usable resolved (a match starts the box default agent), but
+    # the box-wide name that was TRIED is still reported, so a caller can
+    # say "your AGENT_BOX_HOOK_PROFILE names a profile that no longer
+    # exists" rather than just falling silent.
+    resolved = machine.succeed(
+        "sudo -u agent env HOME=/home/agent"
+        f" {spawn_cmd} --resolved-profile 'github:defangdevs/*'"
+    )
+    assert json.loads(resolved) == {
+        "profile": None, "missing": ["triage"],
+    }, resolved
     machine.succeed(
         f"sudo -u agent env HOME=/home/agent agent-box-session rm {ghosted}"
     )
@@ -1348,6 +1360,15 @@
     )
     assert "agent profile watchbot" in launch, launch
     assert "spawnConfig.profile" in launch, launch
+    # --resolved-profile answers the same question as MACHINE-readable JSON
+    # (#582), for a caller that wants the bare name rather than a sentence to
+    # scrape it out of — the settings page badges a watch's row with this.
+    resolved = machine.succeed(
+        "sudo -u agent env HOME=/home/agent"
+        " LOCAL_WEBHOOK_STATE_DIR=/home/agent/.local/state/local-webhook"
+        f" {spawn_cmd} --resolved-profile github:defangdevs/watch-profile"
+    )
+    assert json.loads(resolved) == {"profile": "watchbot", "missing": []}, resolved
     # A topic with no watch-level profile still reports the box-wide one.
     launch = machine.succeed(
         "sudo -u agent env HOME=/home/agent"
@@ -1355,6 +1376,12 @@
         f" {spawn_cmd} --preamble github:defangdevs/no-watch-profile"
     )
     assert "agent profile boxwide" in launch, launch
+    resolved = machine.succeed(
+        "sudo -u agent env HOME=/home/agent"
+        " LOCAL_WEBHOOK_STATE_DIR=/home/agent/.local/state/local-webhook"
+        f" {spawn_cmd} --resolved-profile github:defangdevs/no-watch-profile"
+    )
+    assert json.loads(resolved) == {"profile": "boxwide", "missing": []}, resolved
 
     # An unusable WATCH profile must not cost the box-wide one. It used to:
     # the watch's name displaced the box-wide one BEFORE validation, so one
@@ -1368,6 +1395,19 @@
     )
     assert "agent profile boxwide" in launch, launch
     assert "IGNORED, no such profile" not in launch, launch
+    # ...and --resolved-profile names the box-wide profile it fell back to
+    # AND the watch-level name it passed over — so a delete-time warning and
+    # a row badge can both say "boxwide (and 'ghost' not found)" rather than
+    # only ever seeing the winner.
+    resolved = machine.succeed(
+        "sudo -u agent env HOME=/home/agent"
+        " LOCAL_WEBHOOK_STATE_DIR=/home/agent/.local/state/local-webhook"
+        " LOCAL_WEBHOOK_SPAWN_CONFIG='{\"profile\": \"ghost\"}'"
+        f" {spawn_cmd} --resolved-profile github:defangdevs/no-watch-profile"
+    )
+    assert json.loads(resolved) == {
+        "profile": "boxwide", "missing": ["ghost"],
+    }, resolved
     # A non-string value is ignored rather than stringified into a name.
     # webhook.py drops one when it reads the filter file, so no delivery
     # carries it — but that file is documented as hand-editable, and
@@ -1886,6 +1926,10 @@
         "1 event notification",        # and counted on that session's row
         f'data-fold="subs-{hook_name}"',   # a spawned session's seeded topic
         "Automatic session rule",      # the shared dispatch list, its own panel
+        # #582: which profile a standing watch starts belongs on the ROW,
+        # not only in the fold an operator has to open to find it.
+        "Profile: panelbot",           # panel-profile's own worker...
+        "No profile - box default agent",  # ...and panel's, which names none
         # The endpoint half of the same panel: what to register in the
         # sender, per configured source, paste-ready with a copy button.
         # Until this, both halves were reachable only by running
@@ -1915,8 +1959,13 @@
         )
 
     # The standing watches are NOT session-scoped, so they are the one thing
-    # that must not have moved into a session's fold.
-    watches = page.split("Standing watch")[-1]
+    # that must not have moved into a session's fold. Split on the panel's
+    # OWN heading, not the "Standing watch" wording the panel used to carry:
+    # that string left this page entirely when the panel was renamed to
+    # "Automations" (#259), so the split matched nothing and silently
+    # returned the whole page - every assertion below still passed, just
+    # with no isolation from the Sessions and Profiles panels above it.
+    watches = page.split("<h2>Automations</h2>")[-1]
     assert "github:defangdevs/agent-box" in watches, watches
 
     # A watch row says what a match DOES, not why someone subscribed (#259):
@@ -1928,6 +1977,18 @@
     assert "You are a fresh agent session started by" in watches, watches
     assert "(&quot;standing watch: triage&quot;)" in watches, watches
     assert "hook-&lt;key&gt;-&lt;hex&gt;" in watches, watches
+    # And the row for panel-profile's own watch carries its badge, isolated
+    # to the Automations panel the same way (#582).
+    assert "Profile: panelbot" in watches, watches
+
+    # The Profiles panel says the reverse (#582): panelbot is spent by a
+    # live watch, so deleting it is not a no-op, and the row says so before
+    # anyone has to press the button to find out.
+    profiles_html = page.split("<h2>Profiles</h2>", 1)[-1].split(
+        "<h2>Automations</h2>", 1)[0]
+    assert "used by 1 standing watch" in profiles_html, profiles_html
+    assert ("It is used by 1 standing watch: github:defangdevs/panel-profile"
+            in profiles_html), profiles_html
     # And the note is no longer a paragraph on the row itself.
     assert 'wh-note">standing watch: triage' not in page, page