fix: scope circuit device ids to the panel that owns them

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## 2.5.3 — two simulated panels no longer publish over each other
+
+**A simulated panel already added to Home Assistant has to be removed and re-added**, because its circuits get new device ids and so its circuit entities get
+new unique ids.
+
+### Fixed
+
+- **Two simulated panels running in one add-on no longer collide on their circuits' topics**, where circuit device ids were derived from the circuit id alone
+  and the shipped configs reuse ids such as `solar_inverter` across panel sizes, so each panel's readings overwrote the other's every tick.
+
 ## 2.5.2 — discovery hands over an address, not an internal alias
 
 ### Fixed

DEVELOPER.md

@@ -482,6 +482,9 @@ ebus/5/{serial}/{node}/{property}
 | `evse-0`          | EV charger: status, lock state, advertised current                     |
 | `power-flows`     | Aggregated: PV, battery, grid, site power                              |
 
+`{circuit-uuid}` is a UUID v5 over `{panel-serial}/{circuit-id}`. It is scoped to the panel because the shipped configs reuse circuit ids such as
+`solar_inverter` across panel sizes, and two panels in one add-on publish to one broker.
+
 ### Settable Properties
 
 Control circuits by publishing to `/set` topics:

panelbench/Dockerfile

@@ -32,7 +32,7 @@ EXPOSE 18883 8081 18080
 LABEL io.hass.name="SPAN PanelBench" \
       io.hass.description="Simulates a SPAN electrical panel for testing and upgrade modeling" \
       io.hass.type="addon" \
-      io.hass.version="2.5.2" \
+      io.hass.version="2.5.3" \
       io.hass.arch="aarch64|amd64"
 
 CMD ["/run.sh"]

panelbench/config.yaml

@@ -1,6 +1,6 @@
 name: "SPAN PanelBench"
 description: "Simulates a SPAN electrical panel for testing and upgrade modeling"
-version: "2.5.2"
+version: "2.5.3"
 slug: "panelbench"
 url: "https://github.com/SpanPanel/panelbench"
 image: "ghcr.io/spanpanel/panelbench/{arch}"

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "panelbench"
-version = "2.5.2"
+version = "2.5.3"
 description = "Standalone eBus simulator for SPAN panels"
 requires-python = ">=3.14"
 dependencies = [

src/panelbench/__init__.py

@@ -1,3 +1,3 @@
 """Standalone eBus simulator for SPAN panels."""
 
-__version__ = "2.5.2"
+__version__ = "2.5.3"

src/panelbench/emitter_adapter/instance_ids.py

@@ -2,7 +2,9 @@
 
 Circuit UUIDs were lifted from publisher.py so the simulator's derivation matches
 what the legacy publisher produced: UUID v5 with a fixed namespace, so the same
-circuit_id always yields the same UUID across restarts.
+circuit always yields the same UUID across restarts. The name hashed is
+``<panel-serial>/<circuit-id>`` rather than the circuit id alone — see
+`stable_circuit_uuid`.
 
 The rest of the device ids live here for a different reason. They follow the
 migration guide's Device ID Stability table, because **a Home Assistant entity's
@@ -13,7 +15,7 @@
 
     Panel         <panel-serial>
     Lugs          <panel-serial>-lugs-{up,dn}
-    Circuit       <circuit-uuid>
+    Circuit       <circuit-uuid>   (uuid5 of <panel-serial>/<circuit-id>)
     BESS/PV/EVSE  <proxier-id>-<identifier>   (proxied; proxier is the panel)
     MID           <bess-id>-mid
 
@@ -40,9 +42,31 @@
 _CIRCUIT_NAMESPACE = uuid.UUID("a1b2c3d4-e5f6-7890-abcd-ef1234567890")
 
 
-def stable_circuit_uuid(circuit_id: str) -> str:
-    """Return a deterministic dashless UUID for a circuit identifier."""
-    return str(uuid.uuid5(_CIRCUIT_NAMESPACE, circuit_id)).replace("-", "")
+def stable_circuit_uuid(panel_id: str, circuit_id: str) -> str:
+    """Deterministic dashless UUID for a circuit, scoped to the panel that owns it.
+
+    Every other id here is already panel-scoped, because every other device is named
+    relative to its proxier. A circuit's was not: it hashed the YAML `id` alone, and
+    those ids are shared vocabulary across the shipped configs — `MAIN_32.yaml` and
+    `MAIN_40.yaml` both have a `solar_inverter` and an `oven`. One panel per broker
+    makes that harmless, which is why it survived; two panels in one add-on publish
+    to one broker, and the two `solar_inverter`s then claim the same device id and
+    the same `ebus/5/<uuid>/...` topics. Both panels write every tick, so each
+    circuit's readings alternate between two unrelated loads and a consumer sees
+    energy counters that fall as often as they rise.
+
+    Hashing `<panel-serial>/<circuit-id>` scopes the id to its owner the way the
+    `<proxier>-<identifier>` forms do. The separator is `/` and not `-` because a
+    panel serial may itself contain `-`, and any separator the serial can contain
+    admits two different (panel, circuit) pairs hashing the same name.
+
+    Real firmware cannot hit the collision — a panel has its own broker — so this is
+    an emulator-only defect. The derivation is nonetheless shared byte-for-byte with
+    the flat simulator, which publishes the same circuit ids for the same config: the
+    firmware-upgrade rehearsal stops one and starts the other on one panel, and a
+    circuit whose id changed at the swap strands its Home Assistant history.
+    """
+    return str(uuid.uuid5(_CIRCUIT_NAMESPACE, f"{panel_id}/{circuit_id}")).replace("-", "")
 
 
 def lugs_device_ids(panel_id: str) -> tuple[str, str]:

src/panelbench/emitter_adapter/runtime.py

@@ -272,7 +272,10 @@ async def start_clone(
     ``start`` or ``stop``."""
     manifest = build_manifest(engine.config)
 
-    uuid_to_circuit_id = {stable_circuit_uuid(c["id"]): c["id"] for c in engine.config["circuits"]}
+    panel_id = engine.config["panel_config"]["serial_number"]
+    uuid_to_circuit_id = {
+        stable_circuit_uuid(panel_id, c["id"]): c["id"] for c in engine.config["circuits"]
+    }
 
     # The emitter registers internal default /set handlers from the empty
     # SetterRegistry — no producer-side wiring required.
@@ -431,6 +434,10 @@ def _feeds_for_device_type(config: SimulationConfig, device_type: str) -> list[s
     circuits = config.get("circuits")
     if not isinstance(templates, dict) or not isinstance(circuits, list):
         return []
+    # Read from the config being walked, not from a serial handed in beside it: a
+    # feed id must be the id the *owner* of these circuits publishes, and taking
+    # both from one mapping is what makes that true by construction.
+    panel_id = config["panel_config"]["serial_number"]
     feeds: list[str] = []
     for item in circuits:
         if not isinstance(item, dict):
@@ -442,5 +449,5 @@ def _feeds_for_device_type(config: SimulationConfig, device_type: str) -> list[s
         if isinstance(template, dict) and template.get("device_type") == device_type:
             circuit_id = item.get("id")
             if circuit_id is not None:
-                feeds.append(stable_circuit_uuid(str(circuit_id)))
+                feeds.append(stable_circuit_uuid(panel_id, str(circuit_id)))
     return feeds

src/panelbench/emitter_adapter/spec_generator.py

@@ -141,6 +141,7 @@ def _lugs_instances(profile: SimulationConfig) -> list[DeviceInstance]:
 
 def _circuit_instances(profile: SimulationConfig) -> list[DeviceInstance]:
     templates = profile.get("circuit_templates") or {}
+    panel_id = profile["panel_config"]["serial_number"]
     instances: list[DeviceInstance] = []
     for idx, c in enumerate(profile.get("circuits") or [], start=1):
         tabs = c.get("tabs") or [0]
@@ -165,7 +166,7 @@ def _circuit_instances(profile: SimulationConfig) -> list[DeviceInstance]:
         instances.append(
             DeviceInstance(
                 entity_class="circuit",
-                instance_id=stable_circuit_uuid(c["id"]),
+                instance_id=stable_circuit_uuid(panel_id, c["id"]),
                 display_name=c.get("name", c["id"]),
                 metadata={
                     "tab-numbers": ",".join(str(int(t)) for t in tabs if t),
@@ -331,18 +332,18 @@ def _pv_instance(profile: SimulationConfig) -> DeviceInstance | None:
 
 def _evse_instances(profile: SimulationConfig) -> list[DeviceInstance]:
     evse_cfg = profile.get("evse") or {}
+    panel_id = profile["panel_config"]["serial_number"]
     feed_circuits = _circuits_for_device_type(profile, "evse")
     explicit_feed = str(evse_cfg["feed"]) if "feed" in evse_cfg else None
     if explicit_feed:
         feeds = [explicit_feed]
     else:
-        feeds = [stable_circuit_uuid(circuit["id"]) for circuit in feed_circuits]
+        feeds = [stable_circuit_uuid(panel_id, circuit["id"]) for circuit in feed_circuits]
     if not feeds and evse_cfg.get("enabled"):
         feeds = [""]
     if not feeds:
         return []
 
-    panel_id = profile["panel_config"]["serial_number"]
     base_metadata = {
         "vendor-name": str(evse_cfg.get("vendor", "SPAN")),
         "model": str(evse_cfg.get("product", "SPAN Drive")),
@@ -465,7 +466,7 @@ def _feed_circuit_id(profile: SimulationConfig, device_type: str) -> str | None:
     circuit = _first_circuit_for_device_type(profile, device_type)
     if circuit is None:
         return None
-    return stable_circuit_uuid(circuit["id"])
+    return stable_circuit_uuid(profile["panel_config"]["serial_number"], circuit["id"])
 
 
 def _first_circuit_for_device_type(

src/panelbench/engine.py

@@ -931,11 +931,12 @@ async def get_tick_inputs(self) -> dict[str, Any]:
         # Apply the v0.3.0 sign convention: producers (PV) report negative
         # power; consumers report positive. SimulatedCircuit stores magnitudes
         # only; the energy_mode tells direction.
+        panel_id = self.serial_number
         circuit_powers: dict[str, float] = {}
         for cid, circuit in self._circuits.items():
             mag = circuit.instant_power_w
             signed = -mag if circuit.energy_mode == "producer" else mag
-            circuit_powers[stable_circuit_uuid(cid)] = signed
+            circuit_powers[stable_circuit_uuid(panel_id, cid)] = signed
 
         return {
             "current_time": current_time,