diff --git a/decnet/agent/executor.py b/decnet/agent/executor.py
index 3c1030f..76eaff2 100644
--- a/decnet/agent/executor.py
+++ b/decnet/agent/executor.py
@@ -87,14 +87,44 @@ async def teardown(decky_id: str | None = None) -> None:
         await asyncio.to_thread(clear_state)
 
 
+def _decky_runtime_states(config: DecnetConfig) -> dict[str, dict[str, Any]]:
+    """Map decky_name → {"running": bool, "services": {svc: container_state}}.
+
+    Queried so the master can tell, after a partial-failure deploy, which
+    deckies actually came up instead of tainting the whole shard as failed.
+    Best-effort: a docker error returns an empty map, not an exception.
+    """
+    try:
+        import docker  # local import — agent-only path
+        client = docker.from_env()
+        live = {c.name: c.status for c in client.containers.list(all=True, ignore_removed=True)}
+    except Exception:  # pragma: no cover — defensive
+        log.exception("_decky_runtime_states: docker query failed")
+        return {}
+
+    out: dict[str, dict[str, Any]] = {}
+    for d in config.deckies:
+        svc_states = {
+            svc: live.get(f"{d.name}-{svc.replace('_', '-')}", "absent")
+            for svc in d.services
+        }
+        out[d.name] = {
+            "running": bool(svc_states) and all(s == "running" for s in svc_states.values()),
+            "services": svc_states,
+        }
+    return out
+
+
 async def status() -> dict[str, Any]:
     state = await asyncio.to_thread(load_state)
     if state is None:
         return {"deployed": False, "deckies": []}
     config, _compose_path = state
+    runtime = await asyncio.to_thread(_decky_runtime_states, config)
     return {
         "deployed": True,
         "mode": config.mode,
         "compose_path": str(_compose_path),
         "deckies": [d.model_dump() for d in config.deckies],
+        "runtime": runtime,
     }
diff --git a/decnet/web/router/swarm/api_deploy_swarm.py b/decnet/web/router/swarm/api_deploy_swarm.py
index b15f4b7..2b19ebc 100644
--- a/decnet/web/router/swarm/api_deploy_swarm.py
+++ b/decnet/web/router/swarm/api_deploy_swarm.py
@@ -98,14 +98,28 @@ async def dispatch_decnet_config(
             return SwarmHostResult(host_uuid=host_uuid, host_name=host["name"], ok=True, detail=body)
         except Exception as exc:
             log.exception("swarm.deploy dispatch failed host=%s", host["name"])
+            # Compose-up is partial-success-friendly: one decky failing to
+            # build doesn't roll back the ones that already came up. Ask the
+            # agent which containers actually exist before painting the whole
+            # shard red — otherwise decky1 and decky2 look "failed" even
+            # though they're live on the worker.
+            runtime: dict[str, Any] = {}
+            try:
+                async with AgentClient(host=host) as probe:
+                    snap = await probe.status()
+                runtime = snap.get("runtime") or {}
+            except Exception:
+                log.warning("swarm.deploy: runtime probe failed host=%s — marking shard failed", host["name"])
             for d in shard:
+                rstate = runtime.get(d.name) or {}
+                is_up = bool(rstate.get("running"))
                 await repo.upsert_decky_shard(
                     {
                         "decky_name": d.name,
                         "host_uuid": host_uuid,
                         "services": json.dumps(d.services),
-                        "state": "failed",
-                        "last_error": str(exc)[:512],
+                        "state": "running" if is_up else "failed",
+                        "last_error": None if is_up else str(exc)[:512],
                         "updated_at": datetime.now(timezone.utc),
                     }
                 )
diff --git a/tests/swarm/test_swarm_api.py b/tests/swarm/test_swarm_api.py
index 02f0759..77629d8 100644
--- a/tests/swarm/test_swarm_api.py
+++ b/tests/swarm/test_swarm_api.py
@@ -273,6 +273,68 @@ def test_deploy_rejects_missing_host_uuid(client: TestClient, stub_agent) -> Non
     assert "host_uuid" in resp.json()["detail"]
 
 
+def test_deploy_partial_failure_only_marks_actually_failed_decky(
+    client: TestClient, repo, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """docker compose up is partial-success-friendly: one failed service
+    doesn't roll back the ones already up. The master must probe /status
+    after a dispatch exception so healthy deckies aren't painted red just
+    because a sibling in the same shard failed."""
+
+    class _PartialFailAgent:
+        def __init__(self, host=None, **_):
+            self._host = host or {}
+
+        async def __aenter__(self):
+            return self
+
+        async def __aexit__(self, *exc):
+            return None
+
+        async def deploy(self, config, **kw):
+            raise RuntimeError("Server error '500 Internal Server Error'")
+
+        async def status(self):
+            return {
+                "deployed": True,
+                "runtime": {
+                    "decky1": {"running": True, "services": {"ssh": "running"}},
+                    "decky2": {"running": True, "services": {"ssh": "running"}},
+                    "decky3": {"running": False, "services": {"ssh": "absent"}},
+                },
+            }
+
+    from decnet.web.router.swarm import api_deploy_swarm as deploy_mod
+    monkeypatch.setattr(deploy_mod, "AgentClient", _PartialFailAgent)
+
+    h1 = client.post(
+        "/swarm/enroll",
+        json={"name": "decktest", "address": "192.168.1.47", "agent_port": 8765},
+    ).json()
+
+    cfg = {
+        "mode": "swarm",
+        "interface": "eth0",
+        "subnet": "192.168.1.0/24",
+        "gateway": "192.168.1.1",
+        "deckies": [
+            _decky_dict("decky1", h1["host_uuid"], "192.168.1.2"),
+            _decky_dict("decky2", h1["host_uuid"], "192.168.1.3"),
+            _decky_dict("decky3", h1["host_uuid"], "192.168.1.4"),
+        ],
+    }
+    resp = client.post("/swarm/deploy", json={"config": cfg})
+    assert resp.status_code == 200
+    assert resp.json()["results"][0]["ok"] is False
+
+    shards = {s["decky_name"]: s for s in client.get("/swarm/deckies").json()}
+    assert shards["decky1"]["state"] == "running"
+    assert shards["decky1"]["last_error"] is None
+    assert shards["decky2"]["state"] == "running"
+    assert shards["decky3"]["state"] == "failed"
+    assert "500" in (shards["decky3"]["last_error"] or "")
+
+
 def test_deploy_rejects_non_swarm_mode(client: TestClient, stub_agent) -> None:
     cfg = {
         "mode": "unihost",