diff --git a/assets/sourceos/bin/turtle-netwatch b/assets/sourceos/bin/turtle-netwatch
index 592c47d8178..cac18a758cf 100755
--- a/assets/sourceos/bin/turtle-netwatch
+++ b/assets/sourceos/bin/turtle-netwatch
@@ -223,12 +223,47 @@ def _load_obs(args) -> list[dict[str, Any]]:
     return [json.loads(l) for l in src.read_text().splitlines() if l.strip()]
 
 
+def _discover_hellgraph() -> Path | None:
+    """Zero-config: $HELLGRAPH_HOME -> a sibling ~/dev/hellgraph checkout with a
+    built ingest bin. Returns the repo root or None (caller fails SOFT — graph
+    memory is not a security mutation)."""
+    root = os.environ.get("HELLGRAPH_HOME")
+    cands = [Path(root)] if root else [p / "hellgraph" for p in Path(__file__).resolve().parents]
+    for c in cands:
+        if (c / "bin" / "hellgraph-agent-ingest.mjs").exists() and (c / "ts" / "dist" / "index.mjs").exists():
+            return c
+    return None
+
+
+def _ingest_to_hellgraph(ku: dict[str, Any]) -> dict[str, Any]:
+    """Ingest a KnowledgeUpdate into hellgraph's AtomSpace. FAIL-SOFT: if node or
+    hellgraph is unavailable, the delta is still on the sink; we just report that
+    it was not ingested (memory, not a fail-closed gate)."""
+    hg = _discover_hellgraph()
+    if hg is None:
+        return {"ingested": False, "reason": "hellgraph not found (set $HELLGRAPH_HOME); "
+                "System Graph delta written to sink but not ingested"}
+    if not shutil.which("node"):
+        return {"ingested": False, "reason": "node not on PATH; delta on sink, not ingested"}
+    try:
+        r = subprocess.run(["node", str(hg / "bin" / "hellgraph-agent-ingest.mjs"), "-"],
+                           input=json.dumps(ku), text=True, capture_output=True, timeout=30)
+        if r.returncode != 0:
+            return {"ingested": False, "reason": f"hellgraph ingest failed: {r.stderr.strip()[:200]}"}
+        return {"ingested": True, "hellgraph": json.loads(r.stdout or "{}").get("ingested", {})}
+    except Exception as exc:  # fail-soft
+        return {"ingested": False, "reason": f"ingest error: {exc}"}
+
+
 def cmd_graph(args) -> int:
     ku = build_system_graph(_load_obs(args))
     out = state_dir() / "system_graph.json"
     out.write_text(json.dumps(ku, indent=2))
-    _print(args, ku if args.json else {"nodes": len(ku["patch"]["nodes"]),
-                                       "edges": len(ku["patch"]["edges"]), "sink": str(out)})
+    result: dict[str, Any] = {"nodes": len(ku["patch"]["nodes"]),
+                              "edges": len(ku["patch"]["edges"]), "sink": str(out)}
+    if getattr(args, "ingest", False):
+        result["ingest"] = _ingest_to_hellgraph(ku)
+    _print(args, ku if args.json else result)
     return 0
 
 
@@ -489,6 +524,9 @@ def main(argv=None) -> int:
         s.add_argument("--json", action="store_true")
         if name in ("graph", "detect"):
             s.add_argument("--from", dest="from", default=None)
+        if name == "graph":
+            s.add_argument("--ingest", action="store_true",
+                           help="ingest the System Graph delta into hellgraph's AtomSpace (fail-soft)")
     o = sub.add_parser("observe")
     o.add_argument("--window", type=int, default=5)
     o.add_argument("--interval", type=int, default=1)
diff --git a/assets/sourceos/runbooks/netwatch.yaml b/assets/sourceos/runbooks/netwatch.yaml
index acbe08cbea9..bd5eb1a393a 100644
--- a/assets/sourceos/runbooks/netwatch.yaml
+++ b/assets/sourceos/runbooks/netwatch.yaml
@@ -10,8 +10,8 @@ steps:
     desc: "Point-in-time connection snapshot (portable: ss on Linux, lsof on macOS). Verifies a collector is present."
   - cmd: turtle-netwatch observe --window 15 --interval 3
     desc: "Observe for 15s; emit agent.v1 Observation events to the netwatch sink (schemas/agent/observation.avsc)."
-  - cmd: turtle-netwatch graph
-    desc: "Project the observations into a System Graph subgraph (KnowledgeUpdate delta) for hellgraph AtomSpace ingestion."
+  - cmd: turtle-netwatch graph --ingest
+    desc: "Project the observations into a System Graph subgraph (KnowledgeUpdate delta) AND ingest it into hellgraph's AtomSpace as queryable memory (fail-soft: if hellgraph is absent the delta still lands on the sink). Omit --ingest to only write the delta."
   - cmd: turtle-netwatch detect
     desc: "Scan the window for anomalies — beaconing (low-variance periodic contact) and egress fan-out. Exit 2 if any found."
   - cmd: turtle-netwatch propose --action block-domain --target suspicious.example
diff --git a/assets/sourceos/tests/test_turtle_netwatch.py b/assets/sourceos/tests/test_turtle_netwatch.py
index b228ac9356c..2c0dc196363 100644
--- a/assets/sourceos/tests/test_turtle_netwatch.py
+++ b/assets/sourceos/tests/test_turtle_netwatch.py
@@ -156,3 +156,21 @@ class A:  # minimal args
 if __name__ == "__main__":
     import pytest
     sys.exit(pytest.main([__file__, "-q"]))
+
+
+def test_graph_ingest_fails_soft_without_hellgraph(tmp_path, monkeypatch):
+    # graph --ingest with no hellgraph -> ingested:false, exit 0 (memory, NOT fail-closed)
+    monkeypatch.setenv("SOURCEOS_TERMINAL_RECEIPTS", str(tmp_path / "r"))
+    monkeypatch.setenv("HELLGRAPH_HOME", str(tmp_path / "no-hellgraph"))
+    # seed one observation so the graph has content
+    obs = nw.state_dir() / "observations.jsonl"
+    obs.write_text(json.dumps(_obs("1.2.3.4", "443", "curl", "2026-08-02T00:00:00Z")) + "\n")
+    env = dict(os.environ)
+    env["SOURCEOS_TERMINAL_RECEIPTS"] = str(tmp_path / "r")
+    env["HELLGRAPH_HOME"] = str(tmp_path / "no-hellgraph")
+    r = subprocess.run([sys.executable, str(BIN), "graph", "--ingest"],
+                       env=env, text=True, capture_output=True)
+    assert r.returncode == 0, r.stderr  # fail-SOFT
+    out = json.loads(r.stdout)
+    assert out["ingest"]["ingested"] is False
+    assert "hellgraph not found" in out["ingest"]["reason"]