diff --git a/TOOLING.md b/TOOLING.md
index 49e18f4..dfc1e89 100644
--- a/TOOLING.md
+++ b/TOOLING.md
@@ -159,6 +159,32 @@ files, it is host-local runtime config, and it embeds the same real
 Chrome-profile path already documented above. Recreate it by hand (or from
 this section) after a fresh `mattellite` setup.
 
+## Healthchecks.io
+
+`run-stories.sh` and `run-profiles.sh` each ping a healthchecks.io check —
+`instagram-archiver-stories` / `instagram-archiver-posts` — via `HC_URL`,
+plumbed through to `gdl-cron.sh`. A start ping fires before the sync, a
+finish ping fires after with the run's own log attached as the body (visible
+in the healthchecks.io dashboard, so a failure is diagnosable without SSHing
+in). The trailing URL segment is the exit code: `0` means success, anything
+else fails the check — including the `stories: 0 to sync` → exit 75 remap
+above, so a fully-skipped stories run alerts, not silently passes.
+
+Unset `HC_URL` (e.g. `HC_URL= ./run-stories.sh`) to run without pinging.
+`run-full-sweep.sh` and the reels scripts have no check configured yet.
+
+**This is also why `gdl-sync.py`'s `publish()` no longer treats the routine
+chown-permission warning as a failure (2026-09-14).** The archive share is
+never owned by the ssh user, so rsync's own `chown` step fails on *every*
+run — exit 23, "some files/attrs were not transferred" — even though every
+file lands; "Reading the output" above has documented this as cosmetic since
+this file was created. Before this fix the exit *code* didn't know that, so
+`gdl-sync.py` returned 1 on every clean run too — harmless when a human was
+reading the log anyway, but it would have made every healthcheck ping report
+a normal run as a failure. Only that specific permission-warning shape is
+masked; a real transfer failure sharing the same exit code (23) still fails
+loudly, verified with both a real captured rsync failure and unit tests.
+
 ## Remotes
 
 | remote | what goes there |
diff --git a/scripts/gdl-cron.sh b/scripts/gdl-cron.sh
index b151772..a73cc5a 100755
--- a/scripts/gdl-cron.sh
+++ b/scripts/gdl-cron.sh
@@ -15,6 +15,13 @@ set -eu
 
 MODE="${1:?usage: gdl-cron.sh stories|profiles|full-sweep}"
 
+# healthchecks.io (or compatible) ping URL, e.g. https://hc-ping.com/<uuid>.
+# Set by the run-*.sh wrapper for whichever mode has a check configured;
+# unset here means no ping, silently. A ping failure (network blip, check
+# deleted) must never fail the sync itself -- hence `|| true` throughout, and
+# a short timeout (-m) so a hung ping can't hang the run.
+HC_URL="${HC_URL:-}"
+
 GDL_HOME="${GDL_HOME:-$HOME/gdl}"
 INDEX="${GDL_INDEX:-https://instaarchive.ergosteur.com}"
 PUBLISH="${GDL_PUBLISH:-agentapi@10.20.28.200:/volume1/rslsync/sync/Instagram-archive/archives/}"
@@ -57,6 +64,8 @@ esac
 
 mkdir -p "$GDL_HOME/logs"
 
+[ -n "$HC_URL" ] && curl -fsS -m 10 --retry 3 -o /dev/null "$HC_URL/start" || true
+
 # Staging is wiped every run ON PURPOSE. What we already hold is decided by the
 # skip-archive (--download-archive), never by which files happen to be sitting
 # in staging, so starting empty is correct -- and it keeps the publish rsync
@@ -104,6 +113,14 @@ fi
 
 echo "=== exit $status at $(date -Is) ===" | tee -a "$LOG"
 
+# The log becomes the ping body -- healthchecks.io keeps the last ping's body
+# and shows it in the dashboard, so a failure is diagnosable without SSHing
+# in. The trailing URL segment is the exit code by convention: 0 means
+# success, anything else means fail (this is how the "0 skipped" -> 75
+# remap above also reaches the dashboard as a failure, not a quiet success).
+[ -n "$HC_URL" ] && curl -fsS -m 10 --retry 3 --data-binary "@$LOG" \
+  -o /dev/null "$HC_URL/$status" || true
+
 # Keep the log directory from growing without bound.
 ls -1t "$GDL_HOME/logs" | tail -n +30 | while read -r old; do
   rm -f "$GDL_HOME/logs/$old"
diff --git a/scripts/gdl-sync.py b/scripts/gdl-sync.py
index 358080f..67f633c 100755
--- a/scripts/gdl-sync.py
+++ b/scripts/gdl-sync.py
@@ -748,7 +748,27 @@ def publish(staging: Path, dest: str, dry_run: bool) -> int:
         return 0
     cmd = rsync_command(staging, dest, dry_run)
     print("    " + " ".join(cmd))
-    return subprocess.run(cmd).returncode
+    result = subprocess.run(cmd, capture_output=True, text=True)
+    sys.stdout.write(result.stdout)
+    sys.stderr.write(result.stderr)
+    if result.returncode == 0:
+        return 0
+
+    # The archive share is never owned by the ssh user, so rsync's `chown`
+    # step fails on every single run -- exit 23 ("some files/attrs were not
+    # transferred"), even though every file landed. This is long documented
+    # (TOOLING.md "Reading the output") as something to read past, not a
+    # real failure -- but until now the exit CODE didn't know that, so it
+    # was 1 on every clean run too, silently. Only mask it when every rsync
+    # error line is that specific permission warning; anything else (a real
+    # transfer failure sharing the same exit code) still fails loudly.
+    err_lines = [l for l in result.stderr.splitlines() if l.startswith("rsync:")]
+    if (result.returncode == 23 and err_lines
+            and all("failed to set permissions" in l for l in err_lines)):
+        print("    (rsync exit 23 was only the expected chown-permission "
+              "warning; files landed)")
+        return 0
+    return result.returncode
 
 
 def run_post_urls(args) -> int:
diff --git a/scripts/run-profiles.sh b/scripts/run-profiles.sh
index cb567ba..fe98687 100755
--- a/scripts/run-profiles.sh
+++ b/scripts/run-profiles.sh
@@ -3,4 +3,7 @@
 # does this), ~5 min. Covers everything but is no substitute for stories.sh --
 # a story posted and expired between two runs of this is simply gone.
 set -eu
+# healthchecks.io check "instagram-archiver-posts". Override or unset (e.g.
+# HC_URL= ./run-profiles.sh) to run without pinging it.
+export HC_URL="${HC_URL:-https://hc-ping.com/3f40abd8-e9bd-43af-a105-c583efaad88c}"
 exec "$(dirname "$0")/gdl-cron.sh" profiles "$@"
diff --git a/scripts/run-stories.sh b/scripts/run-stories.sh
index 236b7d0..67cbfd2 100755
--- a/scripts/run-stories.sh
+++ b/scripts/run-stories.sh
@@ -6,4 +6,7 @@
 # mode argument; override pacing/paths the same way gdl-cron.sh does, with
 # GDL_* env vars (see gdl-cron.sh's own comments for what's available).
 set -eu
+# healthchecks.io check "instagram-archiver-stories". Override or unset (e.g.
+# HC_URL= ./run-stories.sh) to run without pinging it.
+export HC_URL="${HC_URL:-https://hc-ping.com/9fe7347f-95be-47aa-a46b-affd27691554}"
 exec "$(dirname "$0")/gdl-cron.sh" stories "$@"
diff --git a/scripts/test_gdl_sync.py b/scripts/test_gdl_sync.py
index 5534eda..9b1ccb6 100644
--- a/scripts/test_gdl_sync.py
+++ b/scripts/test_gdl_sync.py
@@ -12,10 +12,12 @@ whose absence got the archive's Instagram account suspended.
 import datetime as dt
 import importlib.util
 import json
+import subprocess
 import sys
 import tempfile
 import unittest
 from pathlib import Path
+from unittest import mock
 
 _spec = importlib.util.spec_from_file_location(
     "gdl_sync", Path(__file__).with_name("gdl-sync.py"))
@@ -208,6 +210,48 @@ class Publishing(unittest.TestCase):
             self.assertIn(pattern, cmd)
         self.assertIn("--dry-run", cmd)
 
+    def _publish_with(self, returncode, stderr=""):
+        with tempfile.TemporaryDirectory() as d:
+            staging = Path(d)
+            (staging / "file.txt").write_text("x")  # publish() skips empty dirs
+            completed = subprocess.CompletedProcess(
+                args=["rsync"], returncode=returncode, stdout="", stderr=stderr)
+            with mock.patch("subprocess.run", return_value=completed):
+                return gdl.publish(staging, "host:/dest", dry_run=False)
+
+    def test_a_clean_rsync_is_success(self):
+        self.assertEqual(self._publish_with(0), 0)
+
+    def test_the_expected_chown_warning_is_not_a_failure(self):
+        # The exact shape seen on every real run: the archive share is never
+        # owned by the ssh user, so rsync's own chown step fails -- exit 23,
+        # "some files/attrs were not transferred" -- even though every file
+        # landed. TOOLING.md documents this as something to read past; the
+        # exit CODE needs to agree, or every healthcheck ping reports a
+        # clean run as a failure.
+        stderr = (
+            'rsync: failed to set permissions on "/dest/.": Operation not permitted (1)\n'
+            'rsync: failed to set permissions on "/dest/user": Operation not permitted (1)\n'
+            'rsync error: some files/attrs were not transferred (see previous errors) '
+            '(code 23) at main.c(1347) [sender=3.4.1]\n'
+        )
+        self.assertEqual(self._publish_with(23, stderr), 0)
+
+    def test_a_real_transfer_failure_still_fails(self):
+        # Same exit code (23) can also mean a real problem -- e.g. a file
+        # vanishing mid-transfer -- so only the SPECIFIC permission-warning
+        # shape above is masked, not the exit code in general.
+        stderr = (
+            'rsync: [sender] readlink_stat("/stage/broken") failed: '
+            'No such file or directory (2)\n'
+            'rsync error: some files/attrs were not transferred (see previous errors) '
+            '(code 23) at main.c(1347) [sender=3.4.1]\n'
+        )
+        self.assertEqual(self._publish_with(23, stderr), 23)
+
+    def test_an_unrelated_exit_code_still_fails(self):
+        self.assertEqual(self._publish_with(1, "rsync: some other error\n"), 1)
+
 
 class PostUrl(unittest.TestCase):
     """--post-url: a one-off fetch outside the tracked profile list, whose