update CHANGELOG

.gitea/workflows/ci.yml

@@ -25,12 +25,12 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/v')  # Only run on tag push
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
 
       - name: Set up Go Environment
         uses: actions/setup-go@v4
         with:
-          go-version: '1.24'
+          go-version: '1.26'
 
       - name: Build Binary
         run: make build
@@ -72,7 +72,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/v')  # Only run on tag push
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -102,7 +102,7 @@ jobs:
     outputs:
       chart-updated: ${{ steps.filter.outputs.chart }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
       - name: Check Chart Changed
         uses: dorny/paths-filter@v3
         id: filter
@@ -118,7 +118,7 @@ jobs:
     if: ${{ needs.check-chart.outputs.chart-updated == 'true' }}
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
 
       - name: Install Helm
         env:

AGENTS.md

@@ -16,16 +16,55 @@ Exporter for Rheem EcoNet / Rheemcloud water heaters, built on the
   HTTP/gRPC server startup. The client is stateless REST, so `ShutdownFunc` is
   effectively a no-op (the poll goroutine stops on ctx cancel).
 - `pkg/econet/econetclient/` — a minimal EcoNet REST client (ClearBlade
-  backend). `client.go` does the 3 REST calls (auth → `getUserDataForApp` →
+  backend). `client.go` does the read REST calls (auth → `getUserDataForApp` →
   `dynamicAction` usage) and caches a snapshot under an `RWMutex`; `device.go`
   decodes the `@...` datapoints into a flat `Device` struct (ported from
   kevinburke/rheemcloud-go, minus MQTT). `Devices()` is empty until the first
   `Refresh` succeeds — consumers just see an empty list (no nil-guarding).
   **No MQTT**, so `WiFiSignal` and `Running`/`RunningState` stay zero.
+- **Writes (SetMode)**: `Client.SetMode` changes a unit's operating mode by
+  publishing a desired-state message over ClearBlade's REST publish endpoint
+  (`POST /message/{systemKey}/publish`, topic `user/{account_id}/device/desired`,
+  payload `{transactionId, device_name, serial_number, "@MODE": <idx>}`). This
+  is the HTTP equivalent of the app's MQTT publish — **no MQTT client needed**.
+  `@MODE` is an *index* into the device's reported mode list, so `device.go`
+  retains that list (`modeEnumText`) and maps a slug → index (`modeIndex`);
+  supported modes are device-specific (`Device.SupportedModes`). The change is
+  **applied asynchronously** — the new mode only shows up on a later `Refresh`,
+  and a 200 from publish means "accepted", not "applied".
 - `pkg/econet/econetgrpc/` — `EconetService` gRPC impl (`ListDevices`,
-  `GetDevice`) + `deviceToProto`. Does **not** own a client; it's injected.
-- `pkg/econet/econetmcp/` — MCP server at `/api/mcp`; the `list_water_heaters`
-  tool delegates to the gRPC server.
+  `GetDevice`, `SetMode`) + `deviceToProto`. Does **not** own a client; it's
+  injected. `SetMode` maps the proto `Mode` enum → client slug; note MCP calls
+  it in-process and so **bypass the protovalidate interceptor** (the gRPC/REST
+  paths don't), hence `SetMode` re-checks the enum itself.
+- `pkg/econet/econetmcpgen/` — **active** MCP server at `/api/mcp`. Registers
+  the tools generated by protoc-gen-go-mcp (`api/econet/v1alpha1/v1alpha1mcp/`)
+  against our go-sdk `*mcp.Server` via the `runtime/gosdk` adapter, forwarding
+  in-process to the gRPC server. Exposes the same package API as `econetmcp`.
+- `pkg/econet/econetmcp/` — the older hand-written MCP server; a single
+  `list_water_heaters` tool delegating to the gRPC server. Kept in place as a
+  fallback. **Switch between the two** with the aliased `econetmcp` import in
+  `pkg/econet/econet.go` (one line — both packages export identical symbols).
+- `pkg/econet/econetui/` — admin UI served at **`/`** (the root; the HTTP
+  server is not "under `/api`" — only the grpc-gateway is, via
+  `grpcGatewayPath`). Gated by `enableWebUI` (default true). Server-rendered
+  `html/template` + embedded assets (`embed.FS`: Pico.css classless, HTMX,
+  per-`generic_type` SVG icons) with a dark-mode toggle (persisted in
+  `localStorage`). Reads devices and writes mode through the in-process gRPC
+  server, same as the MCP packages. Routes: `GET /` (page), `GET /ui/devices`
+  (HTMX poll partial, every 30s), `POST /ui/devices/{serial}/mode` (returns a
+  re-rendered card), `GET /ui/devices/{serial}/debug` (raw device JSON for the
+  🐛 modal), `GET /static/`. A **fill-level meter** visualizes hot-water
+  availability. `iconFor` matches `@TYPE` loosely (substring, case/spacing
+  insensitive) since real values vary (e.g. `heatpumpWaterHeaterGen5`).
+  Template funcs (`fillClass`/`fillWidth`) take **int32** to match proto fields
+  — `html/template` is strict about arg types.
+  **Pending state** for a mode change is best-effort: `pending.go` holds a
+  TTL-bounded (`pendingTTL`, 90s) desired-mode hint, shown as an "Updating…"
+  badge and cleared once the reported mode converges; a full page load ignores
+  it (fresh reported state), the poll honors it. **Auth is left to the edge**
+  (oauth2-proxy) — the UI/write live at `/` and `/ui/`; keep `/health` and
+  `/metrics` on skip-auth so probes/Prometheus keep working.
 - `pkg/econet/econetmetrics/` — OTEL observable gauges (read the client
   snapshot at scrape time; no poller of its own).
 
@@ -41,6 +80,14 @@ that's all it takes — no extra wiring.
 
 - `costPerKWH` is **US dollars per kWh** (0.18 = 18¢), feeding
   `econet_energy_cost_dollars`.
+- **The `default:` tag is NOT applied at runtime for custom `ServiceConfig`
+  fields** — `LoadEnv` uses plain `env.Parse` (no `DefaultValueTagName`), so
+  `default:` only feeds the JSON schema. A bool that must default to true
+  therefore can't be a plain `bool` (zero value = false); `enableWebUI` is a
+  `*bool` where nil ⇒ enabled (read via `WebUIEnabled()`). `disableWaterUsage`
+  is a plain `bool` because its desired default (poll water usage) is the zero
+  value — set it true to skip the wasted water-usage REST call on units that
+  don't report it.
 - `econetTLSInsecure` (env `ECONET_TLS_INSECURE`) skips TLS certificate
   verification when connecting to the EcoNet cloud API. It exists because the
   upstream host (cloudblade) serves a
@@ -68,6 +115,8 @@ that's all it takes — no extra wiring.
 ## Workflow
 
 - Regenerate proto: `make proto` (buf; `PROTO_DIRS=proto/econet/v1alpha1/*`).
+  This also runs the `protoc-gen-go-mcp` plugin (see `buf.gen.yaml`), emitting
+  the MCP registrars under `api/econet/v1alpha1/v1alpha1mcp/`.
 - Regenerate config schema after config changes: `make schema`.
 - Build/test: `go build ./... && go test ./...`.
 - `econetclient.Device` is a plain struct, so `deviceToProto` and the datapoint
@@ -82,3 +131,11 @@ Creds are configured via `ECONET_EMAIL` / `ECONET_PASSWORD`. Run
 (streamable HTTP; POST to `/api/mcp/` with trailing slash — bare `/api/mcp`
 307-redirects). The REST gateway needs `grpcGatewayPathStrip: true` in
 config.yaml (otherwise the `/api` prefix isn't stripped and routes 404).
+
+`SetMode` (write) can be driven three ways once a real device is loaded:
+`grpcurl -plaintext -d '{"serial_number":"<sn>","mode":"MODE_HEAT_PUMP"}' :8081 econet.v1alpha1.EconetService/SetMode`,
+`POST /api/v1alpha1/devices/<sn>/mode` with `{"mode":"MODE_HEAT_PUMP"}`, or the
+MCP `econet_v1alpha1_EconetService_SetMode` tool. **Unverified against a live
+account**: whether the user token is authorized to publish over REST (same
+authority as MQTT, but Rheem's topic ACL is untested) — this is the one thing
+that can't be confirmed without a real unit.

CHANGELOG.md

@@ -4,6 +4,70 @@ All notable changes to econet-exporter are documented here. The format is
 based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this
 project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+## [v0.5.0] - 2026-07-16
+
+### Added
+
+* **Admin UI** at `/` (`econetui`): a server-rendered dashboard of devices and
+  their status (connectivity, running state, setpoint, hot-water, alerts) with a
+  per-device mode dropdown that writes via the in-process gRPC server. HTMX for
+  interactivity (30s auto-refresh, card-level swaps), Pico.css + embedded SVG
+  icons per device type, a hot-water **fill-level meter**, a 🐛 debug button
+  that shows the raw device JSON, and a persisted **dark-mode toggle** — all
+  served from a single binary via `embed.FS`, responsive down to mobile. Mode
+  changes show a best-effort, TTL-bounded "Updating…" pending badge that
+  reconciles against the reported state (or falls back to a fresh fetch if it
+  never lands). Auth is intentionally left to the edge (e.g. oauth2-proxy);
+  `/health` and `/metrics` stay unauthenticated.
+* `enableWebUI` config (env `ECONET_ENABLE_WEB_UI`, default **true**) to toggle
+  the admin UI, and `disableWaterUsage` (env `ECONET_DISABLE_WATER_USAGE`,
+  default false) to skip the per-device water-usage REST call on units that
+  don't report it.
+* `MODE_ELECTRIC_GAS` added to the `Mode` enum — real devices report a combined
+  "Electric/Gas" mode that was previously decoded as unknown and dropped from
+  the settable-mode list.
+* `supported_modes` on the `Device` proto message (the settable modes for that
+  unit), populated from the device's reported mode list and surfaced over gRPC,
+  REST, and MCP.
+
+## [v0.4.0] - 2026-07-16
+
+### Added
+
+* **Mode control (first mutating RPC).** New `SetMode` RPC on `EconetService`,
+  exposed over gRPC, the REST gateway (`POST /v1alpha1/devices/{serial}/mode`),
+  and as an MCP tool. Writes go out over ClearBlade's REST publish endpoint
+  (`POST /message/{systemKey}/publish`, topic `user/{account_id}/device/desired`,
+  payload `{"@MODE": <idx>, ...}`) — the HTTP equivalent of the app's MQTT
+  publish, so **no MQTT client is required**. The mode is applied
+  asynchronously by the Rheem cloud and only reflected on a later poll.
+* `Mode` proto enum (`off`, `electric`, `energy-saving`, `heat-pump`,
+  `high-demand`, `gas`, `performance`, `vacation`) with protovalidate rejecting
+  the unspecified value. The enum flows into the MCP tool's input schema, so
+  clients see the valid modes. Supported modes are validated per-device against
+  the unit's reported mode list (`@MODE` is published as an index into it).
+* Generated MCP server (`econetmcpgen`) built from the proto via
+  `protoc-gen-go-mcp`, now mounted at `/api/mcp`, forwarding in-process to the
+  gRPC server through the go-sdk adapter. The hand-written `econetmcp` package
+  is retained as a one-line-switchable fallback in `pkg/econet/econet.go`.
+* Optional Grafana dashboard shipped as a ConfigMap in the Helm chart. Enable
+  with `hull.config.settings.grafanaDashboard.enabled=true`; the ConfigMap is
+  labeled `grafana_dashboard: "1"` for the Grafana sidecar to auto-import. The
+  dashboard uses the default Prometheus datasource (no hard-coded UID) and has a
+  multi-select `Device` filter driven by `econet_friendly_name`. Covers connect/
+  heating/mode/setpoint/hot-water/alerts, setpoint range, hot-water availability,
+  energy + cost + water usage, a heating-state timeline, WiFi signal, and a
+  device-info table. Sidecar label/value and Grafana folder are configurable.
+
+### Changed
+
+* MCP tool surface changed with the switch to generated tools: `/api/mcp` now
+  serves `econet_v1alpha1_EconetService_ListDevices`, `_GetDevice`, and
+  `_SetMode` (structured JSON output) instead of the single `list_water_heaters`
+  summary tool. Switch back via the aliased import in `pkg/econet/econet.go`.
+
 ## [v0.3.0] - 2026-07-05
 
 ### Changed

README.md

@@ -58,6 +58,22 @@ Polled usage: `econet_energy_usage_kwh`, `econet_water_usage_gallons`,
 > Note: `econet_wifi_signal_db` is only delivered over Rheem's MQTT push stream,
 > which this exporter does not use — it stays at `0`.
 
+### 📈 Grafana dashboard
+
+The Helm chart ships a ready-made Grafana dashboard
+(`helm/dashboards/econet-exporter.json`). It is **off by default**; enable it by
+setting `hull.config.settings.grafanaDashboard.enabled=true`, which renders a
+ConfigMap labeled `grafana_dashboard: "1"` for the [Grafana sidecar](https://github.com/grafana/helm-charts/tree/main/charts/grafana#sidecar-for-dashboards)
+to auto-import. The dashboard uses the **default Prometheus datasource** (no
+hard-coded UID) and has a multi-select **Device** filter backed by
+`econet_friendly_name`. Tunables under `grafanaDashboard`: `label` / `labelValue`
+(match your sidecar's watch config) and `folder` (target Grafana folder).
+
+```sh
+helm upgrade --install econet ./helm \
+  --set hull.config.settings.grafanaDashboard.enabled=true
+```
+
 ## 📂 Project Structure
 - `proto/econet/v1alpha1/` - Protobuf definitions (source).
 - `api/econet/v1alpha1/` - Generated proto, grpc, grpc-gateway code.

api/econet/v1alpha1/econet.pb.go

@@ -24,6 +24,80 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
+// Mode is a settable operating mode for a water heater. The values mirror the
+// kebab-case slugs reported in Device.mode. Not every device supports every
+// mode; the supported set is device-specific (derived from the unit's reported
+// mode list), so SetMode validates against the target device.
+type Mode int32
+
+const (
+	Mode_MODE_UNSPECIFIED   Mode = 0
+	Mode_MODE_OFF           Mode = 1
+	Mode_MODE_ELECTRIC      Mode = 2
+	Mode_MODE_ENERGY_SAVING Mode = 3
+	Mode_MODE_HEAT_PUMP     Mode = 4
+	Mode_MODE_HIGH_DEMAND   Mode = 5
+	Mode_MODE_GAS           Mode = 6
+	Mode_MODE_PERFORMANCE   Mode = 7
+	Mode_MODE_VACATION      Mode = 8
+	Mode_MODE_ELECTRIC_GAS  Mode = 9 // combined electric/gas backup mode (e.g. hybrid units)
+)
+
+// Enum value maps for Mode.
+var (
+	Mode_name = map[int32]string{
+		0: "MODE_UNSPECIFIED",
+		1: "MODE_OFF",
+		2: "MODE_ELECTRIC",
+		3: "MODE_ENERGY_SAVING",
+		4: "MODE_HEAT_PUMP",
+		5: "MODE_HIGH_DEMAND",
+		6: "MODE_GAS",
+		7: "MODE_PERFORMANCE",
+		8: "MODE_VACATION",
+		9: "MODE_ELECTRIC_GAS",
+	}
+	Mode_value = map[string]int32{
+		"MODE_UNSPECIFIED":   0,
+		"MODE_OFF":           1,
+		"MODE_ELECTRIC":      2,
+		"MODE_ENERGY_SAVING": 3,
+		"MODE_HEAT_PUMP":     4,
+		"MODE_HIGH_DEMAND":   5,
+		"MODE_GAS":           6,
+		"MODE_PERFORMANCE":   7,
+		"MODE_VACATION":      8,
+		"MODE_ELECTRIC_GAS":  9,
+	}
+)
+
+func (x Mode) Enum() *Mode {
+	p := new(Mode)
+	*p = x
+	return p
+}
+
+func (x Mode) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (Mode) Descriptor() protoreflect.EnumDescriptor {
+	return file_econet_v1alpha1_econet_proto_enumTypes[0].Descriptor()
+}
+
+func (Mode) Type() protoreflect.EnumType {
+	return &file_econet_v1alpha1_econet_proto_enumTypes[0]
+}
+
+func (x Mode) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Use Mode.Descriptor instead.
+func (Mode) EnumDescriptor() ([]byte, []int) {
+	return file_econet_v1alpha1_econet_proto_rawDescGZIP(), []int{0}
+}
+
 // Device is the live state of a single Rheem EcoNet device
 // (typically a water heater) as reported by the Rheem cloud.
 type Device struct {
@@ -46,6 +120,7 @@ type Device struct {
 	AlertCount           int32                  `protobuf:"varint,16,opt,name=alert_count,json=alertCount,proto3" json:"alert_count,omitempty"`
 	Away                 bool                   `protobuf:"varint,17,opt,name=away,proto3" json:"away,omitempty"`
 	LastUpdated          *timestamppb.Timestamp `protobuf:"bytes,18,opt,name=last_updated,json=lastUpdated,proto3" json:"last_updated,omitempty"`
+	SupportedModes       []Mode                 `protobuf:"varint,19,rep,packed,name=supported_modes,json=supportedModes,proto3,enum=econet.v1alpha1.Mode" json:"supported_modes,omitempty"` // modes this device can be set to (may be empty)
 	unknownFields        protoimpl.UnknownFields
 	sizeCache            protoimpl.SizeCache
 }
@@ -206,6 +281,13 @@ func (x *Device) GetLastUpdated() *timestamppb.Timestamp {
 	return nil
 }
 
+func (x *Device) GetSupportedModes() []Mode {
+	if x != nil {
+		return x.SupportedModes
+	}
+	return nil
+}
+
 type ListDevicesRequest struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	unknownFields protoimpl.UnknownFields
@@ -374,11 +456,109 @@ func (x *GetDeviceResponse) GetDevice() *Device {
 	return nil
 }
 
+type SetModeRequest struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	SerialNumber  string                 `protobuf:"bytes,1,opt,name=serial_number,json=serialNumber,proto3" json:"serial_number,omitempty"`
+	Mode          Mode                   `protobuf:"varint,2,opt,name=mode,proto3,enum=econet.v1alpha1.Mode" json:"mode,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *SetModeRequest) Reset() {
+	*x = SetModeRequest{}
+	mi := &file_econet_v1alpha1_econet_proto_msgTypes[5]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *SetModeRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*SetModeRequest) ProtoMessage() {}
+
+func (x *SetModeRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_econet_v1alpha1_econet_proto_msgTypes[5]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use SetModeRequest.ProtoReflect.Descriptor instead.
+func (*SetModeRequest) Descriptor() ([]byte, []int) {
+	return file_econet_v1alpha1_econet_proto_rawDescGZIP(), []int{5}
+}
+
+func (x *SetModeRequest) GetSerialNumber() string {
+	if x != nil {
+		return x.SerialNumber
+	}
+	return ""
+}
+
+func (x *SetModeRequest) GetMode() Mode {
+	if x != nil {
+		return x.Mode
+	}
+	return Mode_MODE_UNSPECIFIED
+}
+
+type SetModeResponse struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	// Last-known device state. The mode change is applied asynchronously by the
+	// Rheem cloud, so this reflects the requested mode only after a later poll.
+	Device        *Device `protobuf:"bytes,1,opt,name=device,proto3" json:"device,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *SetModeResponse) Reset() {
+	*x = SetModeResponse{}
+	mi := &file_econet_v1alpha1_econet_proto_msgTypes[6]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *SetModeResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*SetModeResponse) ProtoMessage() {}
+
+func (x *SetModeResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_econet_v1alpha1_econet_proto_msgTypes[6]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use SetModeResponse.ProtoReflect.Descriptor instead.
+func (*SetModeResponse) Descriptor() ([]byte, []int) {
+	return file_econet_v1alpha1_econet_proto_rawDescGZIP(), []int{6}
+}
+
+func (x *SetModeResponse) GetDevice() *Device {
+	if x != nil {
+		return x.Device
+	}
+	return nil
+}
+
 var File_econet_v1alpha1_econet_proto protoreflect.FileDescriptor
 
 const file_econet_v1alpha1_econet_proto_rawDesc = "" +
 	"\n" +
-	"\x1ceconet/v1alpha1/econet.proto\x12\x0feconet.v1alpha1\x1a\x1bbuf/validate/validate.proto\x1a\x1cgoogle/api/annotations.proto\x1a\x1fgoogle/protobuf/timestamp.proto\"\xde\x04\n" +
+	"\x1ceconet/v1alpha1/econet.proto\x12\x0feconet.v1alpha1\x1a\x1bbuf/validate/validate.proto\x1a\x1cgoogle/api/annotations.proto\x1a\x1fgoogle/protobuf/timestamp.proto\"\x9e\x05\n" +
 	"\x06Device\x12#\n" +
 	"\rserial_number\x18\x01 \x01(\tR\fserialNumber\x12\x1b\n" +
 	"\tdevice_id\x18\x02 \x01(\tR\bdeviceId\x12#\n" +
@@ -400,17 +580,36 @@ const file_econet_v1alpha1_econet_proto_rawDesc = "" +
 	"\valert_count\x18\x10 \x01(\x05R\n" +
 	"alertCount\x12\x12\n" +
 	"\x04away\x18\x11 \x01(\bR\x04away\x12=\n" +
-	"\flast_updated\x18\x12 \x01(\v2\x1a.google.protobuf.TimestampR\vlastUpdated\"\x14\n" +
+	"\flast_updated\x18\x12 \x01(\v2\x1a.google.protobuf.TimestampR\vlastUpdated\x12>\n" +
+	"\x0fsupported_modes\x18\x13 \x03(\x0e2\x15.econet.v1alpha1.ModeR\x0esupportedModes\"\x14\n" +
 	"\x12ListDevicesRequest\"H\n" +
 	"\x13ListDevicesResponse\x121\n" +
 	"\adevices\x18\x01 \x03(\v2\x17.econet.v1alpha1.DeviceR\adevices\"@\n" +
 	"\x10GetDeviceRequest\x12,\n" +
 	"\rserial_number\x18\x01 \x01(\tB\a\xbaH\x04r\x02\x10\x01R\fserialNumber\"D\n" +
 	"\x11GetDeviceResponse\x12/\n" +
-	"\x06device\x18\x01 \x01(\v2\x17.econet.v1alpha1.DeviceR\x06device2\x83\x02\n" +
+	"\x06device\x18\x01 \x01(\v2\x17.econet.v1alpha1.DeviceR\x06device\"u\n" +
+	"\x0eSetModeRequest\x12,\n" +
+	"\rserial_number\x18\x01 \x01(\tB\a\xbaH\x04r\x02\x10\x01R\fserialNumber\x125\n" +
+	"\x04mode\x18\x02 \x01(\x0e2\x15.econet.v1alpha1.ModeB\n" +
+	"\xbaH\a\x82\x01\x04\x10\x01 \x00R\x04mode\"B\n" +
+	"\x0fSetModeResponse\x12/\n" +
+	"\x06device\x18\x01 \x01(\v2\x17.econet.v1alpha1.DeviceR\x06device*\xcd\x01\n" +
+	"\x04Mode\x12\x14\n" +
+	"\x10MODE_UNSPECIFIED\x10\x00\x12\f\n" +
+	"\bMODE_OFF\x10\x01\x12\x11\n" +
+	"\rMODE_ELECTRIC\x10\x02\x12\x16\n" +
+	"\x12MODE_ENERGY_SAVING\x10\x03\x12\x12\n" +
+	"\x0eMODE_HEAT_PUMP\x10\x04\x12\x14\n" +
+	"\x10MODE_HIGH_DEMAND\x10\x05\x12\f\n" +
+	"\bMODE_GAS\x10\x06\x12\x14\n" +
+	"\x10MODE_PERFORMANCE\x10\a\x12\x11\n" +
+	"\rMODE_VACATION\x10\b\x12\x15\n" +
+	"\x11MODE_ELECTRIC_GAS\x10\t2\x84\x03\n" +
 	"\rEconetService\x12s\n" +
 	"\vListDevices\x12#.econet.v1alpha1.ListDevicesRequest\x1a$.econet.v1alpha1.ListDevicesResponse\"\x19\x82\xd3\xe4\x93\x02\x13\x12\x11/v1alpha1/devices\x12}\n" +
-	"\tGetDevice\x12!.econet.v1alpha1.GetDeviceRequest\x1a\".econet.v1alpha1.GetDeviceResponse\")\x82\xd3\xe4\x93\x02#\x12!/v1alpha1/devices/{serial_number}B\xcb\x01\n" +
+	"\tGetDevice\x12!.econet.v1alpha1.GetDeviceRequest\x1a\".econet.v1alpha1.GetDeviceResponse\")\x82\xd3\xe4\x93\x02#\x12!/v1alpha1/devices/{serial_number}\x12\x7f\n" +
+	"\aSetMode\x12\x1f.econet.v1alpha1.SetModeRequest\x1a .econet.v1alpha1.SetModeResponse\"1\x82\xd3\xe4\x93\x02+:\x01*\"&/v1alpha1/devices/{serial_number}/modeB\xcb\x01\n" +
 	"\x13com.econet.v1alpha1B\vEconetProtoP\x01ZJgitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1\xa2\x02\x03EXX\xaa\x02\x0fEconet.V1alpha1\xca\x02\x0fEconet\\V1alpha1\xe2\x02\x1bEconet\\V1alpha1\\GPBMetadata\xea\x02\x10Econet::V1alpha1b\x06proto3"
 
 var (
@@ -425,28 +624,37 @@ func file_econet_v1alpha1_econet_proto_rawDescGZIP() []byte {
 	return file_econet_v1alpha1_econet_proto_rawDescData
 }
 
-var file_econet_v1alpha1_econet_proto_msgTypes = make([]protoimpl.MessageInfo, 5)
+var file_econet_v1alpha1_econet_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
+var file_econet_v1alpha1_econet_proto_msgTypes = make([]protoimpl.MessageInfo, 7)
 var file_econet_v1alpha1_econet_proto_goTypes = []any{
-	(*Device)(nil),                // 0: econet.v1alpha1.Device
-	(*ListDevicesRequest)(nil),    // 1: econet.v1alpha1.ListDevicesRequest
-	(*ListDevicesResponse)(nil),   // 2: econet.v1alpha1.ListDevicesResponse
-	(*GetDeviceRequest)(nil),      // 3: econet.v1alpha1.GetDeviceRequest
-	(*GetDeviceResponse)(nil),     // 4: econet.v1alpha1.GetDeviceResponse
-	(*timestamppb.Timestamp)(nil), // 5: google.protobuf.Timestamp
+	(Mode)(0),                     // 0: econet.v1alpha1.Mode
+	(*Device)(nil),                // 1: econet.v1alpha1.Device
+	(*ListDevicesRequest)(nil),    // 2: econet.v1alpha1.ListDevicesRequest
+	(*ListDevicesResponse)(nil),   // 3: econet.v1alpha1.ListDevicesResponse
+	(*GetDeviceRequest)(nil),      // 4: econet.v1alpha1.GetDeviceRequest
+	(*GetDeviceResponse)(nil),     // 5: econet.v1alpha1.GetDeviceResponse
+	(*SetModeRequest)(nil),        // 6: econet.v1alpha1.SetModeRequest
+	(*SetModeResponse)(nil),       // 7: econet.v1alpha1.SetModeResponse
+	(*timestamppb.Timestamp)(nil), // 8: google.protobuf.Timestamp
 }
 var file_econet_v1alpha1_econet_proto_depIdxs = []int32{
-	5, // 0: econet.v1alpha1.Device.last_updated:type_name -> google.protobuf.Timestamp
-	0, // 1: econet.v1alpha1.ListDevicesResponse.devices:type_name -> econet.v1alpha1.Device
-	0, // 2: econet.v1alpha1.GetDeviceResponse.device:type_name -> econet.v1alpha1.Device
-	1, // 3: econet.v1alpha1.EconetService.ListDevices:input_type -> econet.v1alpha1.ListDevicesRequest
-	3, // 4: econet.v1alpha1.EconetService.GetDevice:input_type -> econet.v1alpha1.GetDeviceRequest
-	2, // 5: econet.v1alpha1.EconetService.ListDevices:output_type -> econet.v1alpha1.ListDevicesResponse
-	4, // 6: econet.v1alpha1.EconetService.GetDevice:output_type -> econet.v1alpha1.GetDeviceResponse
-	5, // [5:7] is the sub-list for method output_type
-	3, // [3:5] is the sub-list for method input_type
-	3, // [3:3] is the sub-list for extension type_name
-	3, // [3:3] is the sub-list for extension extendee
-	0, // [0:3] is the sub-list for field type_name
+	8, // 0: econet.v1alpha1.Device.last_updated:type_name -> google.protobuf.Timestamp
+	0, // 1: econet.v1alpha1.Device.supported_modes:type_name -> econet.v1alpha1.Mode
+	1, // 2: econet.v1alpha1.ListDevicesResponse.devices:type_name -> econet.v1alpha1.Device
+	1, // 3: econet.v1alpha1.GetDeviceResponse.device:type_name -> econet.v1alpha1.Device
+	0, // 4: econet.v1alpha1.SetModeRequest.mode:type_name -> econet.v1alpha1.Mode
+	1, // 5: econet.v1alpha1.SetModeResponse.device:type_name -> econet.v1alpha1.Device
+	2, // 6: econet.v1alpha1.EconetService.ListDevices:input_type -> econet.v1alpha1.ListDevicesRequest
+	4, // 7: econet.v1alpha1.EconetService.GetDevice:input_type -> econet.v1alpha1.GetDeviceRequest
+	6, // 8: econet.v1alpha1.EconetService.SetMode:input_type -> econet.v1alpha1.SetModeRequest
+	3, // 9: econet.v1alpha1.EconetService.ListDevices:output_type -> econet.v1alpha1.ListDevicesResponse
+	5, // 10: econet.v1alpha1.EconetService.GetDevice:output_type -> econet.v1alpha1.GetDeviceResponse
+	7, // 11: econet.v1alpha1.EconetService.SetMode:output_type -> econet.v1alpha1.SetModeResponse
+	9, // [9:12] is the sub-list for method output_type
+	6, // [6:9] is the sub-list for method input_type
+	6, // [6:6] is the sub-list for extension type_name
+	6, // [6:6] is the sub-list for extension extendee
+	0, // [0:6] is the sub-list for field type_name
 }
 
 func init() { file_econet_v1alpha1_econet_proto_init() }
@@ -459,13 +667,14 @@ func file_econet_v1alpha1_econet_proto_init() {
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_econet_v1alpha1_econet_proto_rawDesc), len(file_econet_v1alpha1_econet_proto_rawDesc)),
-			NumEnums:      0,
-			NumMessages:   5,
+			NumEnums:      1,
+			NumMessages:   7,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
 		GoTypes:           file_econet_v1alpha1_econet_proto_goTypes,
 		DependencyIndexes: file_econet_v1alpha1_econet_proto_depIdxs,
+		EnumInfos:         file_econet_v1alpha1_econet_proto_enumTypes,
 		MessageInfos:      file_econet_v1alpha1_econet_proto_msgTypes,
 	}.Build()
 	File_econet_v1alpha1_econet_proto = out.File

api/econet/v1alpha1/econet.pb.gw.go

@@ -95,6 +95,51 @@ func local_request_EconetService_GetDevice_0(ctx context.Context, marshaler runt
 	return msg, metadata, err
 }
 
+func request_EconetService_SetMode_0(ctx context.Context, marshaler runtime.Marshaler, client EconetServiceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var (
+		protoReq SetModeRequest
+		metadata runtime.ServerMetadata
+		err      error
+	)
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && !errors.Is(err, io.EOF) {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+	if req.Body != nil {
+		_, _ = io.Copy(io.Discard, req.Body)
+	}
+	val, ok := pathParams["serial_number"]
+	if !ok {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "missing parameter %s", "serial_number")
+	}
+	protoReq.SerialNumber, err = runtime.String(val)
+	if err != nil {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "type mismatch, parameter: %s, error: %v", "serial_number", err)
+	}
+	msg, err := client.SetMode(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+}
+
+func local_request_EconetService_SetMode_0(ctx context.Context, marshaler runtime.Marshaler, server EconetServiceServer, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var (
+		protoReq SetModeRequest
+		metadata runtime.ServerMetadata
+		err      error
+	)
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && !errors.Is(err, io.EOF) {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+	val, ok := pathParams["serial_number"]
+	if !ok {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "missing parameter %s", "serial_number")
+	}
+	protoReq.SerialNumber, err = runtime.String(val)
+	if err != nil {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "type mismatch, parameter: %s, error: %v", "serial_number", err)
+	}
+	msg, err := server.SetMode(ctx, &protoReq)
+	return msg, metadata, err
+}
+
 // RegisterEconetServiceHandlerServer registers the http handlers for service EconetService to "mux".
 // UnaryRPC     :call EconetServiceServer directly.
 // StreamingRPC :currently unsupported pending https://github.com/grpc/grpc-go/issues/906.
@@ -141,6 +186,26 @@ func RegisterEconetServiceHandlerServer(ctx context.Context, mux *runtime.ServeM
 		}
 		forward_EconetService_GetDevice_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
 	})
+	mux.Handle(http.MethodPost, pattern_EconetService_SetMode_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		var stream runtime.ServerTransportStream
+		ctx = grpc.NewContextWithServerTransportStream(ctx, &stream)
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		annotatedContext, err := runtime.AnnotateIncomingContext(ctx, mux, req, "/econet.v1alpha1.EconetService/SetMode", runtime.WithHTTPPathPattern("/v1alpha1/devices/{serial_number}/mode"))
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := local_request_EconetService_SetMode_0(annotatedContext, inboundMarshaler, server, req, pathParams)
+		md.HeaderMD, md.TrailerMD = metadata.Join(md.HeaderMD, stream.Header()), metadata.Join(md.TrailerMD, stream.Trailer())
+		annotatedContext = runtime.NewServerMetadataContext(annotatedContext, md)
+		if err != nil {
+			runtime.HTTPError(annotatedContext, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		forward_EconetService_SetMode_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+	})
 
 	return nil
 }
@@ -215,15 +280,34 @@ func RegisterEconetServiceHandlerClient(ctx context.Context, mux *runtime.ServeM
 		}
 		forward_EconetService_GetDevice_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
 	})
+	mux.Handle(http.MethodPost, pattern_EconetService_SetMode_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		annotatedContext, err := runtime.AnnotateContext(ctx, mux, req, "/econet.v1alpha1.EconetService/SetMode", runtime.WithHTTPPathPattern("/v1alpha1/devices/{serial_number}/mode"))
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_EconetService_SetMode_0(annotatedContext, inboundMarshaler, client, req, pathParams)
+		annotatedContext = runtime.NewServerMetadataContext(annotatedContext, md)
+		if err != nil {
+			runtime.HTTPError(annotatedContext, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		forward_EconetService_SetMode_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+	})
 	return nil
 }
 
 var (
 	pattern_EconetService_ListDevices_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1}, []string{"v1alpha1", "devices"}, ""))
 	pattern_EconetService_GetDevice_0   = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 1, 0, 4, 1, 5, 2}, []string{"v1alpha1", "devices", "serial_number"}, ""))
+	pattern_EconetService_SetMode_0     = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 1, 0, 4, 1, 5, 2, 2, 3}, []string{"v1alpha1", "devices", "serial_number", "mode"}, ""))
 )
 
 var (
 	forward_EconetService_ListDevices_0 = runtime.ForwardResponseMessage
 	forward_EconetService_GetDevice_0   = runtime.ForwardResponseMessage
+	forward_EconetService_SetMode_0     = runtime.ForwardResponseMessage
 )

api/econet/v1alpha1/econet_grpc.pb.go

@@ -21,6 +21,7 @@ const _ = grpc.SupportPackageIsVersion9
 const (
 	EconetService_ListDevices_FullMethodName = "/econet.v1alpha1.EconetService/ListDevices"
 	EconetService_GetDevice_FullMethodName   = "/econet.v1alpha1.EconetService/GetDevice"
+	EconetService_SetMode_FullMethodName     = "/econet.v1alpha1.EconetService/SetMode"
 )
 
 // EconetServiceClient is the client API for EconetService service.
@@ -31,6 +32,7 @@ const (
 type EconetServiceClient interface {
 	ListDevices(ctx context.Context, in *ListDevicesRequest, opts ...grpc.CallOption) (*ListDevicesResponse, error)
 	GetDevice(ctx context.Context, in *GetDeviceRequest, opts ...grpc.CallOption) (*GetDeviceResponse, error)
+	SetMode(ctx context.Context, in *SetModeRequest, opts ...grpc.CallOption) (*SetModeResponse, error)
 }
 
 type econetServiceClient struct {
@@ -61,6 +63,16 @@ func (c *econetServiceClient) GetDevice(ctx context.Context, in *GetDeviceReques
 	return out, nil
 }
 
+func (c *econetServiceClient) SetMode(ctx context.Context, in *SetModeRequest, opts ...grpc.CallOption) (*SetModeResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(SetModeResponse)
+	err := c.cc.Invoke(ctx, EconetService_SetMode_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // EconetServiceServer is the server API for EconetService service.
 // All implementations should embed UnimplementedEconetServiceServer
 // for forward compatibility.
@@ -69,6 +81,7 @@ func (c *econetServiceClient) GetDevice(ctx context.Context, in *GetDeviceReques
 type EconetServiceServer interface {
 	ListDevices(context.Context, *ListDevicesRequest) (*ListDevicesResponse, error)
 	GetDevice(context.Context, *GetDeviceRequest) (*GetDeviceResponse, error)
+	SetMode(context.Context, *SetModeRequest) (*SetModeResponse, error)
 }
 
 // UnimplementedEconetServiceServer should be embedded to have
@@ -84,6 +97,9 @@ func (UnimplementedEconetServiceServer) ListDevices(context.Context, *ListDevice
 func (UnimplementedEconetServiceServer) GetDevice(context.Context, *GetDeviceRequest) (*GetDeviceResponse, error) {
 	return nil, status.Error(codes.Unimplemented, "method GetDevice not implemented")
 }
+func (UnimplementedEconetServiceServer) SetMode(context.Context, *SetModeRequest) (*SetModeResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "method SetMode not implemented")
+}
 func (UnimplementedEconetServiceServer) testEmbeddedByValue() {}
 
 // UnsafeEconetServiceServer may be embedded to opt out of forward compatibility for this service.
@@ -140,6 +156,24 @@ func _EconetService_GetDevice_Handler(srv interface{}, ctx context.Context, dec
 	return interceptor(ctx, in, info, handler)
 }
 
+func _EconetService_SetMode_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(SetModeRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(EconetServiceServer).SetMode(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: EconetService_SetMode_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(EconetServiceServer).SetMode(ctx, req.(*SetModeRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 // EconetService_ServiceDesc is the grpc.ServiceDesc for EconetService service.
 // It's only intended for direct use with grpc.RegisterService,
 // and not to be introspected or modified (even as a copy)
@@ -155,6 +189,10 @@ var EconetService_ServiceDesc = grpc.ServiceDesc{
 			MethodName: "GetDevice",
 			Handler:    _EconetService_GetDevice_Handler,
 		},
+		{
+			MethodName: "SetMode",
+			Handler:    _EconetService_SetMode_Handler,
+		},
 	},
 	Streams:  []grpc.StreamDesc{},
 	Metadata: "econet/v1alpha1/econet.proto",

buf.gen.yaml

@@ -24,5 +24,9 @@ plugins:
     opt:
       - merge_file_name=econet-exporter
       - allow_merge=true
+  - local: ["go", "run", "github.com/redpanda-data/protoc-gen-go-mcp/cmd/protoc-gen-go-mcp@latest"]
+    out: api
+    opt:
+      - paths=source_relative
 inputs:
   - directory: proto

buf.lock

@@ -2,8 +2,8 @@
 version: v2
 deps:
   - name: buf.build/bufbuild/protovalidate
-    commit: 50325440f8f24053b047484a6bf60b76
-    digest: b5:74cb6f5c0853c3c10aafc701614194bbd63326bdb8ef4068214454b8894b03ba4113e04b3a33a8321cdf05336e37db4dc14a5e2495db8462566914f36086ba31
+    commit: 435963d1631043e694e56e6bcc3c79c3
+    digest: b5:f4ea07ad2dd94bd7243562f9908b9fb104feef8076040c89d9f7c1dedc074de4d4ce2b997686ef4400f3eccb765a7cfc20ed4acdd70b9a3699351245c61dba97
   - name: buf.build/googleapis/googleapis
     commit: c17df5b2beca46928cc87d5656bd5343
     digest: b5:648a01e0170d4512dea7d564016165decd1ed6e34bef79fe54753e51ad7e27545709ad9157d7551270147d551155c595a2fb0bf5bb33b1c83040ddbce915c604

config.yaml

@@ -5,6 +5,7 @@
 econetEmail: ""
 costPerKWH: 0.0 # US dollars per kWh (e.g. 0.18 = 18 cents), not cents
 pollInterval: 1m # how often device state + daily usage are re-fetched over REST
+enableWebUI: true # serve the admin UI at / (default true; set false to disable)
 
 # go-app config
 name: econet-exporter

contrib/econet-exporter.swagger.json

@@ -67,9 +67,55 @@
           "EconetService"
         ]
       }
+    },
+    "/v1alpha1/devices/{serialNumber}/mode": {
+      "post": {
+        "operationId": "EconetService_SetMode",
+        "responses": {
+          "200": {
+            "description": "A successful response.",
+            "schema": {
+              "$ref": "#/definitions/v1alpha1SetModeResponse"
+            }
+          },
+          "default": {
+            "description": "An unexpected error response.",
+            "schema": {
+              "$ref": "#/definitions/rpcStatus"
+            }
+          }
+        },
+        "parameters": [
+          {
+            "name": "serialNumber",
+            "in": "path",
+            "required": true,
+            "type": "string"
+          },
+          {
+            "name": "body",
+            "in": "body",
+            "required": true,
+            "schema": {
+              "$ref": "#/definitions/EconetServiceSetModeBody"
+            }
+          }
+        ],
+        "tags": [
+          "EconetService"
+        ]
+      }
     }
   },
   "definitions": {
+    "EconetServiceSetModeBody": {
+      "type": "object",
+      "properties": {
+        "mode": {
+          "$ref": "#/definitions/v1alpha1Mode"
+        }
+      }
+    },
     "protobufAny": {
       "type": "object",
       "properties": {
@@ -167,6 +213,13 @@
         "lastUpdated": {
           "type": "string",
           "format": "date-time"
+        },
+        "supportedModes": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/v1alpha1Mode"
+          },
+          "title": "modes this device can be set to (may be empty)"
         }
       },
       "description": "Device is the live state of a single Rheem EcoNet device\n(typically a water heater) as reported by the Rheem cloud."
@@ -190,6 +243,32 @@
           }
         }
       }
+    },
+    "v1alpha1Mode": {
+      "type": "string",
+      "enum": [
+        "MODE_UNSPECIFIED",
+        "MODE_OFF",
+        "MODE_ELECTRIC",
+        "MODE_ENERGY_SAVING",
+        "MODE_HEAT_PUMP",
+        "MODE_HIGH_DEMAND",
+        "MODE_GAS",
+        "MODE_PERFORMANCE",
+        "MODE_VACATION",
+        "MODE_ELECTRIC_GAS"
+      ],
+      "default": "MODE_UNSPECIFIED",
+      "description": "Mode is a settable operating mode for a water heater. The values mirror the\nkebab-case slugs reported in Device.mode. Not every device supports every\nmode; the supported set is device-specific (derived from the unit's reported\nmode list), so SetMode validates against the target device.\n\n - MODE_ELECTRIC_GAS: combined electric/gas backup mode (e.g. hybrid units)"
+    },
+    "v1alpha1SetModeResponse": {
+      "type": "object",
+      "properties": {
+        "device": {
+          "$ref": "#/definitions/v1alpha1Device",
+          "description": "Last-known device state. The mode change is applied asynchronously by the\nRheem cloud, so this reflects the requested mode only after a later poll."
+        }
+      }
     }
   }
 }

contrib/schema.json

@@ -127,6 +127,10 @@
       "default": 0.19,
       "type": "number"
     },
+    "disableWaterUsage": {
+      "default": false,
+      "type": "boolean"
+    },
     "econetEmail": {
       "type": "string"
     },
@@ -137,6 +141,13 @@
       "default": false,
       "type": "boolean"
     },
+    "enableWebUI": {
+      "default": true,
+      "type": [
+        "null",
+        "boolean"
+      ]
+    },
     "environment": {
       "type": "string"
     },

env-sample

@@ -9,6 +9,7 @@ ECONET_EMAIL="you@example.com"
 ECONET_PASSWORD="changeme"
 ECONET_COST_PER_KWH=0.12 ## US dollars per kWh (0.12 = 12 cents), for econet_energy_cost_dollars
 ECONET_USAGE_INTERVAL=5m ## how often to poll energy/water usage history
+ECONET_ENABLE_WEB_UI=true ## serve the admin UI at / (default true; set false to disable)
 
 # App OTEL Config
 APP_OTEL_STDOUT_ENABLED=true ## For testing only

go.mod

@@ -1,12 +1,14 @@
 module gitea.libretechconsulting.com/rmcguire/econet-exporter
 
-go 1.26
+go 1.26.1
 
 require (
 	buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.11-20260415201107-50325440f8f2.1
+	connectrpc.com/connect v1.20.0
 	gitea.libretechconsulting.com/rmcguire/go-app v0.17.1
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0
 	github.com/modelcontextprotocol/go-sdk v1.6.1
+	github.com/redpanda-data/protoc-gen-go-mcp v0.0.0-20260709214304-372b2d56e470
 	github.com/rs/zerolog v1.35.1
 	go.opentelemetry.io/otel/metric v1.44.0
 	go.opentelemetry.io/otel/trace v1.44.0
@@ -36,6 +38,7 @@ require (
 )
 
 require (
+	buf.build/gen/go/redpandadata/common/protocolbuffers/go v1.34.2-20240917150400-3f349e63f44a.2 // indirect
 	buf.build/go/protovalidate v1.2.0 // indirect
 	cel.dev/expr v0.25.2 // indirect
 	github.com/antlr4-go/antlr/v4 v4.13.1 // indirect
@@ -55,6 +58,7 @@ require (
 	github.com/prometheus/common v0.69.0 // indirect
 	github.com/prometheus/otlptranslator v1.0.0 // indirect
 	github.com/prometheus/procfs v0.21.1 // indirect
+	github.com/redpanda-data/common-go/api v0.0.0-20250801174835-9eea07f1ea06 // indirect
 	github.com/rs/cors v1.11.1 // indirect
 	github.com/segmentio/asm v1.2.1 // indirect
 	github.com/segmentio/encoding v0.5.4 // indirect

go.sum

@@ -1,9 +1,13 @@
 buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.11-20260415201107-50325440f8f2.1 h1:s6hzCXtND/ICdGPTMGk7C+/BFlr2Jg5GyH0NKf4XGXg=
 buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.11-20260415201107-50325440f8f2.1/go.mod h1:tvtbpgaVXZX4g6Pn+AnzFycuRK3MOz5HJfEGeEllXYM=
+buf.build/gen/go/redpandadata/common/protocolbuffers/go v1.34.2-20240917150400-3f349e63f44a.2 h1:JyGBchZNUPlQ7/qjieeKq/Cy+/i1vc0H+cIniGZNSFg=
+buf.build/gen/go/redpandadata/common/protocolbuffers/go v1.34.2-20240917150400-3f349e63f44a.2/go.mod h1:wThyg02xJx4K/DA5fg0QlKts8XVPyTT86JC8hPfEzno=
 buf.build/go/protovalidate v1.2.0 h1:DQVrUWkmGTBij+kOYv/x2LLxwcLaGKMdzShj1/6/3H0=
 buf.build/go/protovalidate v1.2.0/go.mod h1:7rYiQEhqvAipoazpVNBBH2S2f8bjG4huMVy1V2Yofn4=
 cel.dev/expr v0.25.2 h1:K6j46C81hXtZQfuX60cVWQFBJahKSE2gfRbNuvr5bFs=
 cel.dev/expr v0.25.2/go.mod h1:hrXvqGP6G6gyx8UAHSHJ5RGk//1Oj5nXQ2NI02Nrsg4=
+connectrpc.com/connect v1.20.0 h1:6TNDAB+WeNd2uolWNlYczB5E0KNNaVMNUEx8JEUsPmQ=
+connectrpc.com/connect v1.20.0/go.mod h1:A2ygJrukXwWy32vkCAAHNVguZrqZ+jeZ9rGRnGR4dN4=
 gitea.libretechconsulting.com/rmcguire/go-app v0.17.1 h1:OdUNAXRoDpB5sC3KdaJC7Rav8MmxiRZC0fRx9YNH1Ks=
 gitea.libretechconsulting.com/rmcguire/go-app v0.17.1/go.mod h1:YBygVa9JBYAP+ibF8FevN1KUe3h5GHWxAdFyU6I8QgA=
 github.com/antlr4-go/antlr/v4 v4.13.1 h1:SqQKkuVZ+zWkMMNkjy5FZe5mr5WURWnlpmOuzYWrPrQ=
@@ -65,6 +69,8 @@ github.com/modelcontextprotocol/go-sdk v1.6.1 h1:0zOSupjKUxPKSocPT1Wtago+mUHU2/u
 github.com/modelcontextprotocol/go-sdk v1.6.1/go.mod h1:kzm3kzFL1/+AziGOE0nUs3gvPoNxMCvkxokMkuFapXQ=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/onsi/gomega v1.37.0 h1:CdEG8g0S133B4OswTDC/5XPSzE1OeP29QOioj2PID2Y=
+github.com/onsi/gomega v1.37.0/go.mod h1:8D9+Txp43QWKhM24yyOBEdpkzN8FvJyAwecBgsU4KU0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h0RJWRi/o0o=
@@ -77,6 +83,10 @@ github.com/prometheus/otlptranslator v1.0.0 h1:s0LJW/iN9dkIH+EnhiD3BlkkP5QVIUVEo
 github.com/prometheus/otlptranslator v1.0.0/go.mod h1:vRYWnXvI6aWGpsdY/mOT/cbeVRBlPWtBNDb7kGR3uKM=
 github.com/prometheus/procfs v0.21.1 h1:GljZCt+zSTS+NZq88cyQ1LjZ+RCHp3uVuabBWA5+OJI=
 github.com/prometheus/procfs v0.21.1/go.mod h1:aB55Cww9pdSJVHk0hUf0inxWyyjPogFIjmHKYgMKmtY=
+github.com/redpanda-data/common-go/api v0.0.0-20250801174835-9eea07f1ea06 h1:9Ecc+Cg1EyqSTIQ6wQKoKk8BqDlBQmR74bJui4qIqsM=
+github.com/redpanda-data/common-go/api v0.0.0-20250801174835-9eea07f1ea06/go.mod h1:klAmWfc8Q3hEZk8geFTMu6f2sk3VUKRS7cv/LvB05ig=
+github.com/redpanda-data/protoc-gen-go-mcp v0.0.0-20260709214304-372b2d56e470 h1:gBvQBXc+MtBa8aGjXTOFLPu+1a+7I0UMu6Np9ofY1Ow=
+github.com/redpanda-data/protoc-gen-go-mcp v0.0.0-20260709214304-372b2d56e470/go.mod h1:1Ulz0OS7NpChjyMu6NWZucui6SEbIsOzAshGfpqWCV8=
 github.com/rodaine/protogofakeit v0.1.1 h1:ZKouljuRM3A+TArppfBqnH8tGZHOwM/pjvtXe9DaXH8=
 github.com/rodaine/protogofakeit v0.1.1/go.mod h1:pXn/AstBYMaSfc1/RqH3N82pBuxtWgejz1AlYpY1mI0=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=

helm/Chart.yaml

@@ -15,7 +15,7 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.1.6
+version: 0.2.10
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
@@ -26,5 +26,5 @@ appVersion: "v0.3.0"
 dependencies:
   - name: hull
     repository: https://vidispine.github.io/hull
-    version: 1.32.2
+    version: 1.36.0
 

helm/templates/grafana-dashboard.yaml

@@ -0,0 +1,20 @@
+{{- $gd := .Values.hull.config.settings.grafanaDashboard | default dict }}
+{{- if $gd.enabled }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Release.Name }}-grafana-dashboard
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app.kubernetes.io/name: {{ .Chart.Name }}
+    app.kubernetes.io/instance: {{ .Release.Name }}
+    {{- /* Label the Grafana sidecar watches for to auto-import dashboards */}}
+    {{ $gd.label | default "grafana_dashboard" }}: {{ $gd.labelValue | default "1" | quote }}
+  {{- with $gd.folder }}
+  annotations:
+    grafana_folder: {{ . | quote }}
+  {{- end }}
+data:
+  econet-exporter.json: |-
+{{ .Files.Get "dashboards/econet-exporter.json" | indent 4 }}
+{{- end }}

helm/values.yaml

@@ -58,6 +58,18 @@ hull:
       otelResourceAttributes: app=econet-exporter
       otlpEndpoint: http://otel.otel.svc.cluster.local:4317 # Replace me
 
+      # Ship a ready-made Grafana dashboard as a ConfigMap for the Grafana
+      # sidecar to auto-import (kiwigrid/k8s-sidecar). Flip enabled to true;
+      # the dashboard uses the default Prometheus datasource and filters by
+      # device name. No datasource UID hard-coding required.
+      grafanaDashboard:
+        enabled: false
+        # Label/value the Grafana sidecar is configured to watch for.
+        label: grafana_dashboard
+        labelValue: "1"
+        # Optional Grafana folder to file the dashboard under (blank = General).
+        folder: ""
+
       serviceType: ClusterIP
       serviceLbIP: "" # Used if serviceTyps=LoadBalancer
 

pkg/config/custom.go

@@ -34,6 +34,19 @@ type ServiceConfig struct {
 	// usage are re-fetched over REST.
 	PollInterval time.Duration `yaml:"pollInterval" json:"pollInterval,omitempty" env:"ECONET_POLL_INTERVAL"`
 
+	// EnableWebUI toggles the admin UI served at /. It defaults to enabled:
+	// a pointer so an unset value (nil) is distinguishable from an explicit
+	// false, which is what makes the default actually true at runtime —
+	// LoadEnv's plain env.Parse does not apply the `default` tag (that tag
+	// only feeds the JSON schema). Use WebUIEnabled to read it.
+	EnableWebUI *bool `yaml:"enableWebUI" json:"enableWebUI,omitempty" env:"ECONET_ENABLE_WEB_UI" default:"true"`
+
+	// DisableWaterUsage skips the per-device water-usage REST call on each
+	// refresh. Handy for units that don't report water usage, where the call is
+	// wasted work and just produces debug-log noise. Zero value (false) keeps
+	// water usage enabled, so unlike EnableWebUI this needs no pointer.
+	DisableWaterUsage bool `yaml:"disableWaterUsage" json:"disableWaterUsage,omitempty" env:"ECONET_DISABLE_WATER_USAGE" default:"false"`
+
 	// Embeds go-app config, used by go-app to
 	// merge custom config into go-app config, and to produce
 	// a complete configuration json schema
@@ -51,6 +64,12 @@ func (c *ServiceConfig) LoadEnv() error {
 	return env.Parse(c)
 }
 
+// WebUIEnabled reports whether the admin UI should be served. Unset defaults to
+// true; set enableWebUI: false (or ECONET_ENABLE_WEB_UI=false) to disable it.
+func (c *ServiceConfig) WebUIEnabled() bool {
+	return c.EnableWebUI == nil || *c.EnableWebUI
+}
+
 // GetPollInterval returns the configured poll interval or the default.
 func (c *ServiceConfig) GetPollInterval() time.Duration {
 	if c.PollInterval <= 0 {

pkg/config/custom_test.go

@@ -0,0 +1,24 @@
+package config
+
+import "testing"
+
+func TestWebUIEnabledDefaultsTrue(t *testing.T) {
+	tru, fls := true, false
+	cases := []struct {
+		name string
+		in   *bool
+		want bool
+	}{
+		{"unset defaults to enabled", nil, true},
+		{"explicit true", &tru, true},
+		{"explicit false", &fls, false},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			c := &ServiceConfig{EnableWebUI: tc.in}
+			if got := c.WebUIEnabled(); got != tc.want {
+				t.Errorf("WebUIEnabled() = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}

pkg/econet/econet.go

@@ -16,8 +16,13 @@ import (
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetclient"
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetgrpc"
-	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetmcp"
+	// MCP server. Aliased so switching implementations is a one-line change.
+	// Generated (protoc-gen-go-mcp) tools:
+	econetmcp "gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetmcpgen"
+	// Hand-written tools (switch back by using this import instead):
+	// econetmcp "gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetmcp"
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetmetrics"
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetui"
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/service"
 )
 
@@ -28,6 +33,7 @@ type EconetService struct {
 	client  *econetclient.Client
 	grpc    *econetgrpc.EconetGRPCServer
 	mcp     *econetmcp.EconetMCPServer
+	ui      *econetui.EconetUIServer
 	metrics *econetmetrics.Collector
 }
 
@@ -44,6 +50,9 @@ func (e *EconetService) Init(ctx context.Context, cfg *config.ServiceConfig) (se
 	e.client = econetclient.New(cfg, e.log)
 	e.grpc = econetgrpc.NewEconetGRPCServer(ctx, cfg, e.client)
 	e.mcp = econetmcp.NewEconetMCPServer(ctx, cfg, e.grpc)
+	if cfg.WebUIEnabled() {
+		e.ui = econetui.NewEconetUIServer(ctx, cfg, e.grpc)
+	}
 	e.metrics = econetmetrics.NewCollector(ctx, cfg, e.client)
 	if err := e.metrics.RegisterGauges(); err != nil {
 		return nil, err
@@ -96,9 +105,13 @@ func (e *EconetService) GetGRPC() *optsgrpc.AppGRPC {
 }
 
 func (e *EconetService) GetHTTP() *optshttp.AppHTTP {
+	handlers := e.mcp.GetHandlers()
+	if e.ui != nil {
+		handlers = append(handlers, e.ui.GetHandlers()...)
+	}
 	return &optshttp.AppHTTP{
 		Ctx:          e.ctx,
-		Handlers:     e.mcp.GetHandlers(),
+		Handlers:     handlers,
 		HealthChecks: e.healthChecks(),
 	}
 }

pkg/econet/econetclient/client.go

@@ -37,6 +37,7 @@ type Client struct {
 	email             string
 	password          string
 	costPerKWH        float64
+	disableWaterUsage bool
 	http              *http.Client
 	log               *zerolog.Logger
 
@@ -55,6 +56,7 @@ func New(cfg *config.ServiceConfig, log *zerolog.Logger) *Client {
 		email:             cfg.EconetEmail,
 		password:          cfg.EconetPassword,
 		costPerKWH:        cfg.CostPerKWH,
+		disableWaterUsage: cfg.DisableWaterUsage,
 		http:              &http.Client{Transport: transport, Timeout: 15 * time.Second},
 		log:               log,
 		devices:           map[string]*Device{},
@@ -100,6 +102,7 @@ func (c *Client) Refresh(ctx context.Context) error {
 	devices := make(map[string]*Device, len(equipment))
 	for _, raw := range equipment {
 		d := newDevice(raw, now)
+		c.traceRawEquipment(d.SerialNumber, raw)
 		if d.SerialNumber == "" {
 			continue
 		}
@@ -113,6 +116,67 @@ func (c *Client) Refresh(ctx context.Context) error {
 	return nil
 }
 
+// SetMode changes a device's operating mode. It resolves the normalized mode
+// slug to the device's @MODE enum index and publishes a desired-state message
+// to the EcoNet cloud over ClearBlade's REST publish endpoint (the HTTP
+// equivalent of the app's MQTT publish). The change is applied asynchronously;
+// the new mode is only reflected after a subsequent Refresh.
+func (c *Client) SetMode(ctx context.Context, serial, mode string) error {
+	c.mu.RLock()
+	d, account := c.devices[serial], c.accountID
+	c.mu.RUnlock()
+	if d == nil {
+		return fmt.Errorf("econet: unknown device %q", serial)
+	}
+	idx, ok := d.modeIndex(mode)
+	if !ok {
+		return fmt.Errorf("econet: device %q does not support mode %q (supported: %s)",
+			serial, mode, strings.Join(d.SupportedModes(), ", "))
+	}
+
+	if err := c.ensureAuth(ctx); err != nil {
+		return err
+	}
+
+	desired, err := json.Marshal(map[string]any{
+		"transactionId": transactionID(),
+		"device_name":   d.DeviceID,
+		"serial_number": d.SerialNumber,
+		"@MODE":         idx,
+	})
+	if err != nil {
+		return err
+	}
+	publish := map[string]any{
+		"topic": "user/" + account + "/device/desired",
+		"body":  string(desired),
+		"qos":   1,
+	}
+
+	path := "/message/" + clearBladeSystemKey + "/publish"
+	if err := c.do(ctx, path, c.userToken(), publish, nil); err != nil {
+		c.clearToken() // token may have expired; re-auth next call
+		return fmt.Errorf("econet: set mode: %w", err)
+	}
+	c.log.Info().Str("serial", serial).Str("mode", mode).Int("modeIndex", idx).
+		Msg("econet: published mode change")
+	return nil
+}
+
+// traceRawEquipment logs one device's undecoded equipment block so the full set
+// of "@..." datapoints (including fields we don't decode, e.g. any image/model)
+// can be inspected. The level guard keeps us from marshaling unless trace is on.
+func (c *Client) traceRawEquipment(serial string, raw map[string]json.RawMessage) {
+	if c.log.GetLevel() > zerolog.TraceLevel {
+		return
+	}
+	b, err := json.Marshal(raw)
+	if err != nil {
+		return
+	}
+	c.log.Trace().Str("serial", serial).RawJSON("equipment", b).Msg("econet: raw equipment payload")
+}
+
 func (c *Client) clearToken() {
 	c.mu.Lock()
 	c.token = ""
@@ -187,6 +251,9 @@ func (c *Client) fetchUsage(ctx context.Context, d *Device) {
 	} else {
 		c.log.Debug().Err(err).Str("serial", d.SerialNumber).Msg("energy usage poll failed")
 	}
+	if c.disableWaterUsage {
+		return
+	}
 	if w, _, err := c.usage(ctx, d, "waterUsage"); err == nil {
 		d.WaterGallons = w
 	} else {
@@ -274,6 +341,11 @@ func (c *Client) do(ctx context.Context, path, token string, body, out any) erro
 	if resp.StatusCode != http.StatusOK {
 		return fmt.Errorf("HTTP %d: %s", resp.StatusCode, bytes.TrimSpace(raw))
 	}
+	// The publish endpoint replies 200 with an empty (or non-JSON) body; callers
+	// that don't need the response pass out == nil.
+	if out == nil || len(bytes.TrimSpace(raw)) == 0 {
+		return nil
+	}
 	return json.Unmarshal(raw, out)
 }
 
@@ -285,6 +357,12 @@ func (c *Client) userToken() string {
 
 // --- usage helpers -------------------------------------------------------
 
+// transactionID mirrors the identifier the Rheem Android app stamps on each
+// desired-state publish: "ANDROID_" + a local second-resolution timestamp.
+func transactionID() string {
+	return "ANDROID_" + time.Now().Format("2006-01-02T15:04:05")
+}
+
 // dayWindow returns ISO-8601 start/end strings covering the current local day,
 // matching pyeconet's formats: energy includes the timezone offset, water does
 // not (the upstream parser is picky).

pkg/econet/econetclient/device.go

@@ -26,6 +26,11 @@ type Device struct {
 	Running      bool   // true when actively heating (decoded from @RUNNING over REST)
 	RunningState string // normalized @RUNNING label: "compressor-running" | "element-running" | "idle" | ...
 
+	// modeEnumText is the raw @MODE enum label list; the slice index is the
+	// integer value published to change the mode. Empty for units without a
+	// settable @MODE (mode changes are unsupported for those).
+	modeEnumText []string
+
 	Setpoint    int
 	SetpointMin int
 	SetpointMax int
@@ -40,6 +45,10 @@ type Device struct {
 	EnergyKWH    float64
 	EnergyType   string // "KWH" or "KBTU"
 	WaterGallons float64
+
+	// Raw is the undecoded equipment payload as received, kept for the web UI's
+	// debug view (and to surface any fields we don't decode).
+	Raw json.RawMessage
 }
 
 // newDevice decodes an equipment block (the raw JSON map for one unit) into
@@ -62,9 +71,34 @@ func newDevice(info map[string]json.RawMessage, now time.Time) *Device {
 	d.FriendlyName = friendlyName(info, d.DeviceID)
 	d.Setpoint, d.SetpointMin, d.SetpointMax = setpoint(info["@SETPOINT"])
 	d.Running, d.RunningState = running(info)
+	d.modeEnumText = modeLabels(info)
+	if b, err := json.Marshal(info); err == nil {
+		d.Raw = b
+	}
 	return d
 }
 
+// SupportedModes returns the normalized mode slugs this device can be set to,
+// in publish-index order. Empty for units without a settable @MODE.
+func (d *Device) SupportedModes() []string {
+	out := make([]string, 0, len(d.modeEnumText))
+	for _, label := range d.modeEnumText {
+		out = append(out, modeFromEnumText(label))
+	}
+	return out
+}
+
+// modeIndex maps a normalized mode slug to the integer value the EcoNet cloud
+// expects in a @MODE publish, matching pyeconet's enumText-position lookup.
+func (d *Device) modeIndex(slug string) (int, bool) {
+	for i, label := range d.modeEnumText {
+		if modeFromEnumText(label) == slug {
+			return i, true
+		}
+	}
+	return 0, false
+}
+
 // --- field decoders ------------------------------------------------------
 
 func connected(info map[string]json.RawMessage) bool {
@@ -201,6 +235,8 @@ func modeFromEnumText(s string) string {
 		return "heat-pump"
 	case "HIGH_DEMAND":
 		return "high-demand"
+	case "ELECTRIC_GAS":
+		return "electric-gas"
 	case "GAS":
 		return "gas"
 	case "PERFORMANCE":
@@ -217,7 +253,7 @@ func modeFromEnumText(s string) string {
 // series regardless of which one is currently active.
 var KnownModes = []string{
 	"off", "electric", "energy-saving", "heat-pump",
-	"high-demand", "gas", "performance", "vacation", "unknown",
+	"high-demand", "electric-gas", "gas", "performance", "vacation", "unknown",
 }
 
 // running reports whether the unit is actively heating and a normalized label

pkg/econet/econetclient/device_test.go

@@ -0,0 +1,66 @@
+package econetclient
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+	"time"
+)
+
+// sampleGen5 is a trimmed but faithful slice of a real getUserDataForApp
+// equipment block for a Rheem Gen5 heat-pump water heater (see the values in
+// the field decoders it exercises: @TYPE, @MODE enumText incl. "Electric/Gas",
+// @HOTWATER "_v2" icon, @SETPOINT limits, @ENABLED, @NAME).
+const sampleGen5 = `{
+  "@TYPE":"heatpumpWaterHeaterGen5",
+  "@CONNECTED":true,
+  "@ENABLED":{"constraints":{"enumText":["Disabled","Enabled "],"lowerLimit":0,"upperLimit":1},"status":"Enabled ","value":1},
+  "@MODE":{"constraints":{"enumText":["Off           ","Energy Saver  ","Heat Pump     ","High Demand   ","Electric/Gas  ","Vacation      "],"lowerLimit":0,"upperLimit":5},"status":"Energy Saver  ","value":1},
+  "@HOTWATER":"ic_tank_hundread_percent_v2.png",
+  "@SETPOINT":{"constraints":{"lowerLimit":110,"upperLimit":140},"value":135},
+  "@NAME":{"constraints":{"stringLength":64},"value":"Heat Pump Water Heater"},
+  "@RUNNING":"",
+  "@ALERTCOUNT":0,
+  "device_name":"3224625639131449",
+  "device_type":"WH",
+  "serial_number":"04-17-1a-0d-22-11-25-c0-01"
+}`
+
+func TestNewDeviceGen5(t *testing.T) {
+	var info map[string]json.RawMessage
+	if err := json.Unmarshal([]byte(sampleGen5), &info); err != nil {
+		t.Fatalf("bad sample: %v", err)
+	}
+	d := newDevice(info, time.Now())
+
+	if d.SerialNumber != "04-17-1a-0d-22-11-25-c0-01" {
+		t.Errorf("serial = %q", d.SerialNumber)
+	}
+	if d.GenericType != "heatpumpWaterHeaterGen5" {
+		t.Errorf("genericType = %q", d.GenericType)
+	}
+	if d.FriendlyName != "Heat Pump Water Heater" {
+		t.Errorf("friendlyName = %q", d.FriendlyName)
+	}
+	if !d.Enabled {
+		t.Errorf("enabled = false, want true")
+	}
+	if d.Mode != "energy-saving" {
+		t.Errorf("mode = %q, want energy-saving", d.Mode)
+	}
+	if d.Setpoint != 135 || d.SetpointMin != 110 || d.SetpointMax != 140 {
+		t.Errorf("setpoint = %d [%d,%d], want 135 [110,140]", d.Setpoint, d.SetpointMin, d.SetpointMax)
+	}
+	if d.HotWaterAvailability != 100 {
+		t.Errorf("hotWater = %d, want 100", d.HotWaterAvailability)
+	}
+	if len(d.Raw) == 0 {
+		t.Errorf("raw payload not retained")
+	}
+
+	// "Electric/Gas" must map to a real, settable mode (not dropped as unknown).
+	want := []string{"off", "energy-saving", "heat-pump", "high-demand", "electric-gas", "vacation"}
+	if got := d.SupportedModes(); !reflect.DeepEqual(got, want) {
+		t.Errorf("supportedModes = %v, want %v", got, want)
+	}
+}

pkg/econet/econetgrpc/device.go

@@ -27,5 +27,18 @@ func deviceToProto(d *econetclient.Device) *pb.Device {
 		AlertCount:           int32(d.AlertCount),
 		Away:                 d.Away,
 		LastUpdated:          timestamppb.New(d.LastUpdated),
+		SupportedModes:       supportedModes(d.SupportedModes()),
 	}
 }
+
+// supportedModes maps the device's mode slugs to proto enums, dropping any that
+// aren't settable (e.g. "unknown").
+func supportedModes(slugs []string) []pb.Mode {
+	out := make([]pb.Mode, 0, len(slugs))
+	for _, slug := range slugs {
+		if m, ok := modeFromSlug(slug); ok {
+			out = append(out, m)
+		}
+	}
+	return out
+}

pkg/econet/econetgrpc/econet.go

@@ -70,3 +70,75 @@ func (s *EconetGRPCServer) GetDevice(ctx context.Context, req *pb.GetDeviceReque
 	span.SetStatus(codes.Ok, "")
 	return &pb.GetDeviceResponse{Device: deviceToProto(d)}, nil
 }
+
+// DeviceRawJSON returns the undecoded EcoNet equipment payload for a device,
+// used by the web UI's debug view. ok is false if the serial is unknown or no
+// raw payload was captured. It is a debug accessor, not part of the RPC surface.
+func (s *EconetGRPCServer) DeviceRawJSON(serial string) ([]byte, bool) {
+	d := s.client.Device(serial)
+	if d == nil || len(d.Raw) == 0 {
+		return nil, false
+	}
+	return d.Raw, true
+}
+
+// modeSlugs maps the settable proto Mode enum to the normalized slugs the
+// client (and Device.mode) use. MODE_UNSPECIFIED is intentionally absent;
+// protovalidate rejects it before we get here.
+var modeSlugs = map[pb.Mode]string{
+	pb.Mode_MODE_OFF:           "off",
+	pb.Mode_MODE_ELECTRIC:      "electric",
+	pb.Mode_MODE_ENERGY_SAVING: "energy-saving",
+	pb.Mode_MODE_HEAT_PUMP:     "heat-pump",
+	pb.Mode_MODE_HIGH_DEMAND:   "high-demand",
+	pb.Mode_MODE_GAS:           "gas",
+	pb.Mode_MODE_PERFORMANCE:   "performance",
+	pb.Mode_MODE_VACATION:      "vacation",
+	pb.Mode_MODE_ELECTRIC_GAS:  "electric-gas",
+}
+
+// ModeSlug returns the normalized slug for a settable Mode, or "" if unknown.
+func ModeSlug(m pb.Mode) string { return modeSlugs[m] }
+
+// modeFromSlug is the reverse of modeSlugs; ok is false for slugs with no
+// settable enum (e.g. "unknown").
+func modeFromSlug(slug string) (pb.Mode, bool) {
+	for m, s := range modeSlugs {
+		if s == slug {
+			return m, true
+		}
+	}
+	return pb.Mode_MODE_UNSPECIFIED, false
+}
+
+func (s *EconetGRPCServer) SetMode(ctx context.Context, req *pb.SetModeRequest) (
+	*pb.SetModeResponse, error,
+) {
+	ctx, span := s.tracer.Start(ctx, "setMode", trace.WithAttributes(
+		attribute.String("serialNumber", req.GetSerialNumber()),
+		attribute.String("mode", req.GetMode().String()),
+	))
+	defer span.End()
+
+	slug, ok := modeSlugs[req.GetMode()]
+	if !ok {
+		err := status.Errorf(grpccodes.InvalidArgument, "unsupported mode %q", req.GetMode())
+		span.SetStatus(codes.Error, err.Error())
+		return nil, err
+	}
+
+	if err := s.client.SetMode(ctx, req.GetSerialNumber(), slug); err != nil {
+		err := status.Error(grpccodes.FailedPrecondition, err.Error())
+		span.SetStatus(codes.Error, err.Error())
+		return nil, err
+	}
+
+	span.SetStatus(codes.Ok, "")
+	// State applies asynchronously; return the last-known snapshot. Guard against
+	// a concurrent refresh evicting the device between publish and lookup.
+	resp := &pb.SetModeResponse{}
+	if d := s.client.Device(req.GetSerialNumber()); d != nil {
+		resp.Device = deviceToProto(d)
+	}
+	return resp, nil
+}

pkg/econet/econetmcp/tool.go

@@ -1,76 +0,0 @@
-package econetmcp
-
-import (
-	"context"
-	"fmt"
-	"strings"
-
-	"github.com/modelcontextprotocol/go-sdk/mcp"
-	"k8s.io/utils/ptr"
-
-	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
-)
-
-var ListDevicesTool = &mcp.Tool{
-	Name:        "list_water_heaters",
-	Title:       "List EcoNet Water Heaters",
-	Description: "Lists Rheem EcoNet devices and their current state (mode, setpoint, " +
-		"hot water availability, connectivity). Optionally filter to one serial number.",
-	Annotations: &mcp.ToolAnnotations{
-		ReadOnlyHint:  true,
-		OpenWorldHint: ptr.To(true),
-	},
-}
-
-type ListDevicesParams struct {
-	SerialNumber string `json:"serial_number,omitempty" jsonschema:"Optional device serial number to return a single device"`
-}
-
-func (m *EconetMCPServer) addListDevicesTool() {
-	mcp.AddTool(m.server, ListDevicesTool, m.listDevicesHandler)
-}
-
-func (m *EconetMCPServer) listDevicesHandler(ctx context.Context, _ *mcp.CallToolRequest, args *ListDevicesParams) (
-	*mcp.CallToolResult, any, error,
-) {
-	m.log.Debug().Str("serial", args.SerialNumber).Msg("list water heaters tool called")
-
-	devices, err := m.lookup(ctx, args.SerialNumber)
-	if err != nil {
-		return &mcp.CallToolResult{IsError: true, Meta: mcp.Meta{"error": err.Error()}}, nil, err
-	}
-
-	return &mcp.CallToolResult{
-		Content: []mcp.Content{&mcp.TextContent{Text: summarizeDevices(devices)}},
-	}, nil, nil
-}
-
-func (m *EconetMCPServer) lookup(ctx context.Context, serial string) ([]*pb.Device, error) {
-	if serial != "" {
-		resp, err := m.econetGRPC.GetDevice(ctx, &pb.GetDeviceRequest{SerialNumber: serial})
-		if err != nil {
-			return nil, err
-		}
-		return []*pb.Device{resp.GetDevice()}, nil
-	}
-
-	resp, err := m.econetGRPC.ListDevices(ctx, &pb.ListDevicesRequest{})
-	if err != nil {
-		return nil, err
-	}
-	return resp.GetDevices(), nil
-}
-
-func summarizeDevices(devices []*pb.Device) string {
-	if len(devices) == 0 {
-		return "No EcoNet devices found."
-	}
-	var b strings.Builder
-	for _, d := range devices {
-		fmt.Fprintf(&b, "%s (%s, serial %s): mode=%s setpoint=%d°F running=%t connected=%t hotWater=%d%% alerts=%d\n",
-			d.GetFriendlyName(), d.GetGenericType(), d.GetSerialNumber(),
-			d.GetMode(), d.GetSetpoint(), d.GetRunning(), d.GetConnected(),
-			d.GetHotWaterAvailability(), d.GetAlertCount())
-	}
-	return strings.TrimRight(b.String(), "\n")
-}

pkg/econet/econetmcp/tool_test.go

@@ -1,38 +0,0 @@
-package econetmcp
-
-import (
-	"strings"
-	"testing"
-
-	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
-)
-
-func TestSummarizeDevices(t *testing.T) {
-	tests := []struct {
-		name    string
-		devices []*pb.Device
-		want    string // substring that must appear
-	}{
-		{"empty", nil, "No EcoNet devices found."},
-		{
-			name: "single",
-			devices: []*pb.Device{{
-				FriendlyName: "Garage",
-				GenericType:  "heatpumpWaterHeater",
-				SerialNumber: "ABC123",
-				Mode:         "heat-pump",
-				Setpoint:     125,
-			}},
-			want: "Garage (heatpumpWaterHeater, serial ABC123): mode=heat-pump setpoint=125",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got := summarizeDevices(tt.devices)
-			if !strings.Contains(got, tt.want) {
-				t.Errorf("summarizeDevices() = %q, want substring %q", got, tt.want)
-			}
-		})
-	}
-}

pkg/econet/econetmcpgen/server.go

@@ -1,8 +1,13 @@
 /*
-Package econetmcp exposes an MCP server, mounted as an HTTP handler at
-/api/mcp, whose tools wrap the EconetService gRPC API.
+Package econetmcpgen exposes an MCP server, mounted as an HTTP handler at
+/api/mcp, whose tools are generated from the EconetService proto by
+protoc-gen-go-mcp and forwarded to the in-process gRPC server.
+
+It is the generated-code counterpart to econetmcp (which hand-writes a single
+list_water_heaters tool). Both expose an identical package API, so switching
+between them is a one-line import change in pkg/econet/econet.go.
 */
-package econetmcp
+package econetmcpgen
 
 import (
 	"context"
@@ -10,8 +15,10 @@ import (
 
 	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
 	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/redpanda-data/protoc-gen-go-mcp/pkg/runtime/gosdk"
 	"github.com/rs/zerolog"
 
+	v1alpha1mcp "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1/v1alpha1mcp"
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
 	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetgrpc"
 )
@@ -46,14 +53,15 @@ func NewEconetMCPServer(ctx context.Context, cfg *config.ServiceConfig,
 }
 
 func (m *EconetMCPServer) GetHandlers() []opts.HTTPHandler {
-	// NOTE: Add other tools here
-	m.addListDevicesTool()
+	// Register the generated tools against the in-process gRPC server via the
+	// go-sdk adapter, so the generated code shares our configured *mcp.Server.
+	v1alpha1mcp.RegisterEconetServiceHandler(gosdk.Wrap(m.server), m.econetGRPC)
 
 	handler := mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
 		return m.server
 	}, &mcp.StreamableHTTPOptions{})
 
-	m.log.Debug().Msg("Econet MCP tools ready")
+	m.log.Debug().Msg("Econet MCP tools ready (generated)")
 
 	return []opts.HTTPHandler{
 		{

pkg/econet/econetui/handlers.go

@@ -0,0 +1,162 @@
+package econetui
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetgrpc"
+)
+
+// cardView is the template model for one device card.
+type cardView struct {
+	Device  *pb.Device
+	Icon    string       // static asset path for the device type
+	Modes   []modeOption // settable modes for the dropdown
+	Pending string       // pretty label of an in-flight mode change, if any
+	Error   string       // last mode-change error, if any
+}
+
+type modeOption struct {
+	Value    string // proto enum name, e.g. MODE_HEAT_PUMP
+	Label    string // display label, e.g. Heat Pump
+	Selected bool
+}
+
+type pageView struct {
+	Devices []cardView
+}
+
+func (s *EconetUIServer) handleIndex(w http.ResponseWriter, r *http.Request) {
+	// A full page load is a "fresh get": show reported state, ignore pending.
+	s.render(w, "layout", pageView{Devices: s.deviceViews(r.Context(), false)})
+}
+
+func (s *EconetUIServer) handleDevices(w http.ResponseWriter, r *http.Request) {
+	// The polling refresh honors pending so an in-flight change stays visible
+	// until it lands or its TTL lapses.
+	s.render(w, "devices", pageView{Devices: s.deviceViews(r.Context(), true)})
+}
+
+func (s *EconetUIServer) handleSetMode(w http.ResponseWriter, r *http.Request) {
+	serial := r.PathValue("serial")
+	modeName := r.FormValue("mode")
+
+	modeVal, ok := pb.Mode_value[modeName]
+	if !ok || pb.Mode(modeVal) == pb.Mode_MODE_UNSPECIFIED {
+		s.renderCard(w, r.Context(), serial, "invalid mode "+modeName)
+		return
+	}
+
+	_, err := s.econetGRPC.SetMode(r.Context(), &pb.SetModeRequest{
+		SerialNumber: serial,
+		Mode:         pb.Mode(modeVal),
+	})
+	if err != nil {
+		s.log.Warn().Err(err).Str("serial", serial).Msg("ui: set mode failed")
+		s.renderCard(w, r.Context(), serial, err.Error())
+		return
+	}
+
+	s.pending.set(serial, econetgrpc.ModeSlug(pb.Mode(modeVal)))
+	s.renderCard(w, r.Context(), serial, "")
+}
+
+// handleDebug returns the raw EcoNet payload for a device, pretty-printed, for
+// the bug-icon modal.
+func (s *EconetUIServer) handleDebug(w http.ResponseWriter, r *http.Request) {
+	serial := r.PathValue("serial")
+	raw, ok := s.econetGRPC.DeviceRawJSON(serial)
+	if !ok {
+		s.render(w, "debug", "No raw payload captured for "+serial+" yet.")
+		return
+	}
+	var buf bytes.Buffer
+	if err := json.Indent(&buf, raw, "", "  "); err != nil {
+		buf.Write(raw)
+	}
+	s.render(w, "debug", buf.String())
+}
+
+// deviceViews builds card views for all devices. When usePending is true, an
+// in-flight mode change is shown as a pending badge (and cleared once the
+// reported mode catches up).
+func (s *EconetUIServer) deviceViews(ctx context.Context, usePending bool) []cardView {
+	resp, err := s.econetGRPC.ListDevices(ctx, &pb.ListDevicesRequest{})
+	if err != nil {
+		s.log.Error().Err(err).Msg("ui: list devices failed")
+		return nil
+	}
+	views := make([]cardView, 0, len(resp.GetDevices()))
+	for _, d := range resp.GetDevices() {
+		views = append(views, s.toCardView(d, usePending))
+	}
+	return views
+}
+
+// renderCard re-renders a single device's card, used for the HTMX swap after a
+// mode change. A successful change is optimistic (pending badge shown).
+func (s *EconetUIServer) renderCard(w http.ResponseWriter, ctx context.Context, serial, errMsg string) {
+	resp, err := s.econetGRPC.GetDevice(ctx, &pb.GetDeviceRequest{SerialNumber: serial})
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusNotFound)
+		return
+	}
+	cv := s.toCardView(resp.GetDevice(), true)
+	cv.Error = errMsg
+	s.render(w, "card", cv)
+}
+
+func (s *EconetUIServer) toCardView(d *pb.Device, usePending bool) cardView {
+	cv := cardView{Device: d, Icon: iconFor(d.GetGenericType())}
+
+	for _, m := range d.GetSupportedModes() {
+		slug := econetgrpc.ModeSlug(m)
+		cv.Modes = append(cv.Modes, modeOption{
+			Value:    m.String(),
+			Label:    prettyMode(slug),
+			Selected: slug == d.GetMode(),
+		})
+	}
+
+	if usePending {
+		if desired, ok := s.pending.get(d.GetSerialNumber()); ok {
+			if desired == d.GetMode() {
+				s.pending.clear(d.GetSerialNumber()) // reported caught up
+			} else {
+				cv.Pending = prettyMode(desired)
+			}
+		}
+	}
+	return cv
+}
+
+func (s *EconetUIServer) render(w http.ResponseWriter, name string, data any) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := s.tmpl.ExecuteTemplate(w, name, data); err != nil {
+		s.log.Error().Err(err).Str("template", name).Msg("ui: render failed")
+	}
+}
+
+// iconFor maps a device's generic type to an embedded SVG asset. It matches
+// loosely (case/spacing/underscore-insensitive substrings) because the reported
+// @TYPE varies in form across firmware (e.g. "heatpumpWaterHeater", "HeatPump",
+// "Hybrid Electric"); unrecognized types fall back to a generic icon.
+func iconFor(genericType string) string {
+	t := strings.NewReplacer(" ", "", "_", "", "-", "").Replace(strings.ToLower(genericType))
+	switch {
+	case strings.Contains(t, "heatpump"), strings.Contains(t, "hybrid"):
+		return "/static/icons/heatpump.svg"
+	case strings.Contains(t, "tankless"):
+		return "/static/icons/tankless.svg"
+	case strings.Contains(t, "gas"):
+		return "/static/icons/gas.svg"
+	case strings.Contains(t, "electric"):
+		return "/static/icons/electric.svg"
+	default:
+		return "/static/icons/unknown.svg"
+	}
+}

pkg/econet/econetui/pending.go

@@ -0,0 +1,54 @@
+package econetui
+
+import (
+	"sync"
+	"time"
+)
+
+// pendingStore holds best-effort "desired mode" hints for the brief, async
+// window between a SetMode publish and the Rheem cloud reporting the new mode.
+// Entries expire after a TTL so a mode change that never takes hold quietly
+// falls back to the reported state (a "fresh get") rather than showing a stuck
+// pending badge forever.
+type pendingStore struct {
+	mu  sync.Mutex
+	ttl time.Duration
+	m   map[string]pendingEntry
+}
+
+type pendingEntry struct {
+	desired   string // desired mode slug
+	expiresAt time.Time
+}
+
+func newPendingStore(ttl time.Duration) *pendingStore {
+	return &pendingStore{ttl: ttl, m: make(map[string]pendingEntry)}
+}
+
+func (p *pendingStore) set(serial, desired string) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.m[serial] = pendingEntry{desired: desired, expiresAt: time.Now().Add(p.ttl)}
+}
+
+// get returns the desired mode slug for a serial, or ("", false) if there is no
+// pending change or it has expired (expired entries are dropped).
+func (p *pendingStore) get(serial string) (string, bool) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	e, ok := p.m[serial]
+	if !ok {
+		return "", false
+	}
+	if time.Now().After(e.expiresAt) {
+		delete(p.m, serial)
+		return "", false
+	}
+	return e.desired, true
+}
+
+func (p *pendingStore) clear(serial string) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	delete(p.m, serial)
+}

pkg/econet/econetui/server.go

@@ -0,0 +1,117 @@
+/*
+Package econetui serves a small admin UI at / for viewing EcoNet devices and
+changing their operating mode. It renders server-side HTML (html/template with
+embedded assets) and uses HTMX for interactivity; device reads and mode writes
+go through the in-process gRPC server, exactly like the MCP packages. Auth is
+left to the edge (oauth2-proxy) — this package serves the human surface at /
+and the mode-write at /ui/, leaving /health, /metrics, and /api untouched.
+*/
+package econetui
+
+import (
+	"context"
+	"embed"
+	"fmt"
+	"html/template"
+	"io/fs"
+	"net/http"
+	"strings"
+	"time"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
+	"github.com/rs/zerolog"
+
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetgrpc"
+)
+
+//go:embed templates/*.html
+var templatesFS embed.FS
+
+//go:embed static
+var staticFS embed.FS
+
+// pendingTTL bounds how long an optimistic mode change is shown before the UI
+// falls back to the reported state.
+const pendingTTL = 90 * time.Second
+
+type EconetUIServer struct {
+	ctx        context.Context
+	cfg        *config.ServiceConfig
+	log        *zerolog.Logger
+	econetGRPC *econetgrpc.EconetGRPCServer
+	tmpl       *template.Template
+	pending    *pendingStore
+}
+
+func NewEconetUIServer(ctx context.Context, cfg *config.ServiceConfig,
+	grpc *econetgrpc.EconetGRPCServer,
+) *EconetUIServer {
+	tmpl := template.Must(template.New("").Funcs(template.FuncMap{
+		"prettyMode": prettyMode,
+		"fillClass":  fillClass,
+		"fillWidth":  fillWidth,
+	}).ParseFS(templatesFS, "templates/*.html"))
+
+	return &EconetUIServer{
+		ctx:        ctx,
+		cfg:        cfg,
+		log:        zerolog.Ctx(ctx),
+		econetGRPC: grpc,
+		tmpl:       tmpl,
+		pending:    newPendingStore(pendingTTL),
+	}
+}
+
+func (s *EconetUIServer) GetHandlers() []opts.HTTPHandler {
+	staticSub, _ := fs.Sub(staticFS, "static")
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /{$}", s.handleIndex)
+	mux.HandleFunc("GET /ui/devices", s.handleDevices)
+	mux.HandleFunc("GET /ui/devices/{serial}/debug", s.handleDebug)
+	mux.HandleFunc("POST /ui/devices/{serial}/mode", s.handleSetMode)
+	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.FS(staticSub))))
+
+	s.log.Debug().Msg("Econet admin UI ready at /")
+
+	return []opts.HTTPHandler{{Prefix: "/", Handler: mux}}
+}
+
+// prettyMode turns a mode slug ("heat-pump") into a display label ("Heat Pump").
+func prettyMode(slug string) string {
+	switch slug {
+	case "":
+		return "Unknown"
+	case "electric-gas":
+		return "Electric/Gas"
+	}
+	words := strings.Split(slug, "-")
+	for i, w := range words {
+		if w != "" {
+			words[i] = strings.ToUpper(w[:1]) + w[1:]
+		}
+	}
+	return strings.Join(words, " ")
+}
+
+// fillClass buckets a hot-water fill percentage into a color class. It takes
+// int32 to match the proto Device field (html/template is strict about types).
+func fillClass(pct int32) string {
+	switch {
+	case pct >= 66:
+		return "fill-high"
+	case pct >= 33:
+		return "fill-mid"
+	default:
+		return "fill-low"
+	}
+}
+
+// fillWidth returns a safe CSS width for the fill bar.
+func fillWidth(pct int32) template.CSS {
+	if pct < 0 {
+		pct = 0
+	}
+	return template.CSS(fmt.Sprintf("width:%d%%", pct))
+}

pkg/econet/econetui/static/app.css

@@ -0,0 +1,151 @@
+/* Layout + components for the EcoNet admin UI. Colors come from Pico's CSS
+   custom properties so light and dark themes both work without overrides. */
+
+body {
+  max-width: 1100px;
+  margin: 0 auto;
+  padding: 2.5rem 2rem;
+}
+
+.app-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 1rem;
+  margin-bottom: 2.5rem;
+}
+.app-header hgroup { margin-bottom: 0; }
+
+.theme-toggle {
+  flex: 0 0 auto;
+  width: 3rem;
+  height: 3rem;
+  padding: 0;
+  border-radius: 50%;
+  font-size: 1.25rem;
+  line-height: 1;
+}
+
+/* Comfortable, capped card width that wraps and centers, so a single device
+   sits in a tidy card surrounded by whitespace rather than stretching wide or
+   getting crammed. min(100%, 420px) keeps it fluid on narrow screens. */
+.device-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(min(100%, 420px), 460px));
+  justify-content: center;
+  gap: 2rem;
+}
+
+.device-card {
+  margin: 0;
+  padding: 2rem;
+  display: flex;
+  flex-direction: column;
+  gap: 1.5rem;
+}
+
+.card-head {
+  display: flex;
+  align-items: center;
+  gap: 1rem;
+}
+.device-icon {
+  flex: 0 0 auto;
+  width: 56px;
+  height: 56px;
+  color: var(--pico-primary);
+}
+.card-title { flex: 1 1 auto; min-width: 0; line-height: 1.3; }
+.card-title strong { display: block; font-size: 1.2rem; }
+.card-title small { color: var(--pico-muted-color); word-break: break-all; }
+
+.bug-btn {
+  flex: 0 0 auto;
+  padding: 0.25rem 0.4rem;
+  background: none;
+  border: none;
+  border-radius: var(--pico-border-radius);
+  font-size: 1.1rem;
+  line-height: 1;
+  cursor: pointer;
+  opacity: 0.55;
+  transition: opacity 0.15s ease;
+}
+.bug-btn:hover { opacity: 1; }
+
+.dot {
+  flex: 0 0 auto;
+  width: 0.8rem;
+  height: 0.8rem;
+  border-radius: 50%;
+  display: inline-block;
+}
+.dot-ok  { background: var(--pico-color-green-500, #22c55e); }
+.dot-off { background: var(--pico-color-red-500, #ef4444); }
+
+.stats {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 1rem 1.5rem;
+}
+.stats > div { display: flex; flex-direction: column; gap: 0.2rem; }
+.stats span { color: var(--pico-muted-color); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }
+.stats b { font-size: 1.1rem; }
+
+.fill { display: flex; flex-direction: column; gap: 0.45rem; }
+.fill-head { display: flex; justify-content: space-between; align-items: baseline; }
+.fill-head span { color: var(--pico-muted-color); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }
+.fill-meter {
+  height: 0.6rem;
+  border-radius: 999px;
+  overflow: hidden;
+  background: color-mix(in srgb, var(--pico-muted-color) 22%, transparent);
+}
+.fill-bar { height: 100%; border-radius: 999px; transition: width 0.4s ease; }
+.fill-high { background: var(--pico-color-green-500, #22c55e); }
+.fill-mid  { background: var(--pico-color-amber-500, #f59e0b); }
+.fill-low  { background: var(--pico-color-red-500, #ef4444); }
+
+.card-foot {
+  display: flex;
+  flex-direction: column;
+  gap: 0.6rem;
+}
+.mode-label { margin: 0; font-size: 0.85rem; color: var(--pico-muted-color); }
+.mode-label select { margin-top: 0.35rem; margin-bottom: 0; }
+.mode-fixed { color: var(--pico-muted-color); }
+
+.badge {
+  align-self: flex-start;
+  padding: 0.2rem 0.55rem;
+  border-radius: var(--pico-border-radius);
+  font-size: 0.8rem;
+}
+.badge-pending {
+  background: var(--pico-primary-background);
+  color: var(--pico-primary-inverse);
+}
+.badge-error {
+  background: var(--pico-color-red-500, #ef4444);
+  color: #fff;
+}
+
+.empty-state { grid-column: 1 / -1; text-align: center; padding: 3rem 1rem; }
+
+.debug-modal pre {
+  max-height: 65vh;
+  overflow: auto;
+  margin: 0;
+}
+.debug-modal code { white-space: pre; }
+
+/* Mobile: tighten spacing; the grid already collapses to a single full-width
+   column via minmax(min(100%, 420px), …). */
+@media (max-width: 480px) {
+  body { padding: 1.25rem 1rem; }
+  .app-header { margin-bottom: 1.5rem; }
+  .app-header h1 { font-size: 1.6rem; }
+  .device-grid { gap: 1.25rem; }
+  .device-card { padding: 1.5rem; gap: 1.25rem; }
+  .device-icon { width: 48px; height: 48px; }
+}

pkg/econet/econetui/static/icons/electric.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+  <rect x="14" y="8" width="20" height="32" rx="4"/>
+  <line x1="18" y1="40" x2="18" y2="43"/>
+  <line x1="30" y1="40" x2="30" y2="43"/>
+  <path d="M25 15l-5 7h4l-1 7 6-8h-4z" fill="currentColor" stroke="none"/>
+</svg>

pkg/econet/econetui/static/icons/gas.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+  <rect x="14" y="6" width="20" height="28" rx="4"/>
+  <line x1="18" y1="34" x2="18" y2="37"/>
+  <line x1="30" y1="34" x2="30" y2="37"/>
+  <path d="M24 38c-3 0-5 2-5 4.5S21 46 24 46s5-1.5 5-3.5c0-3-3-3.5-2-6.5-2 1-3 2.5-3 4.5z"/>
+</svg>

pkg/econet/econetui/static/icons/heatpump.svg

@@ -0,0 +1,7 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+  <rect x="14" y="12" width="20" height="30" rx="4"/>
+  <line x1="18" y1="42" x2="18" y2="45"/>
+  <line x1="30" y1="42" x2="30" y2="45"/>
+  <circle cx="24" cy="9" r="6"/>
+  <path d="M24 5.5v7M20.5 9h7M21.5 6.5l5 5M26.5 6.5l-5 5"/>
+</svg>

pkg/econet/econetui/static/icons/tankless.svg

@@ -0,0 +1,7 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+  <rect x="12" y="10" width="24" height="22" rx="3"/>
+  <line x1="18" y1="32" x2="18" y2="40"/>
+  <line x1="30" y1="32" x2="30" y2="40"/>
+  <line x1="17" y1="17" x2="31" y2="17"/>
+  <circle cx="24" cy="25" r="3"/>
+</svg>

pkg/econet/econetui/static/icons/unknown.svg

@@ -0,0 +1,7 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+  <rect x="14" y="8" width="20" height="32" rx="4"/>
+  <line x1="18" y1="40" x2="18" y2="43"/>
+  <line x1="30" y1="40" x2="30" y2="43"/>
+  <path d="M21 20a3 3 0 1 1 4 2.8c-1 .5-1 1.2-1 2.2"/>
+  <line x1="24" y1="30" x2="24" y2="30.5"/>
+</svg>

pkg/econet/econetui/templates/card.html

@@ -0,0 +1,57 @@
+{{define "card"}}
+<article id="card-{{.Device.SerialNumber}}" class="device-card">
+  <div class="card-head">
+    <img class="device-icon" src="{{.Icon}}" alt="" width="56" height="56">
+    <div class="card-title">
+      <strong>{{.Device.FriendlyName}}</strong>
+      <small>{{.Device.SerialNumber}}</small>
+    </div>
+    <button class="bug-btn" title="Show raw device JSON" aria-label="Show raw device JSON"
+            hx-get="/ui/devices/{{.Device.SerialNumber}}/debug"
+            hx-target="#debug-modal-body"
+            hx-swap="innerHTML"
+            onclick="document.getElementById('debug-modal').showModal()">🐛</button>
+    <span class="dot {{if .Device.Connected}}dot-ok{{else}}dot-off{{end}}"
+          title="{{if .Device.Connected}}Connected{{else}}Disconnected{{end}}"></span>
+  </div>
+
+  <div class="stats">
+    <div><span>Status</span>
+      <b>{{if .Device.Running}}🔥 {{prettyMode .Device.RunningState}}{{else}}Idle{{end}}</b></div>
+    <div><span>Setpoint</span><b>{{.Device.Setpoint}}&deg;F</b></div>
+    <div><span>Alerts</span>
+      <b>{{if gt .Device.AlertCount 0}}⚠ {{.Device.AlertCount}}{{else}}0{{end}}</b></div>
+  </div>
+
+  {{if ge .Device.HotWaterAvailability 0}}
+  <div class="fill">
+    <div class="fill-head"><span>Hot water</span><b>{{.Device.HotWaterAvailability}}%</b></div>
+    <div class="fill-meter">
+      <div class="fill-bar {{fillClass .Device.HotWaterAvailability}}" style="{{fillWidth .Device.HotWaterAvailability}}"></div>
+    </div>
+  </div>
+  {{end}}
+
+  <div class="card-foot">
+    {{if .Modes}}
+      <label class="mode-label">
+        Mode
+        <select name="mode"
+                hx-post="/ui/devices/{{.Device.SerialNumber}}/mode"
+                hx-target="#card-{{.Device.SerialNumber}}"
+                hx-swap="outerHTML"
+                hx-trigger="change"
+                {{if .Pending}}disabled aria-busy="true"{{end}}>
+          {{range .Modes}}
+            <option value="{{.Value}}" {{if .Selected}}selected{{end}}>{{.Label}}</option>
+          {{end}}
+        </select>
+      </label>
+      {{if .Pending}}<span class="badge badge-pending" aria-busy="true">Updating → {{.Pending}}…</span>{{end}}
+    {{else}}
+      <small class="mode-fixed">Mode: {{prettyMode .Device.Mode}} (not settable)</small>
+    {{end}}
+    {{if .Error}}<span class="badge badge-error" role="alert">{{.Error}}</span>{{end}}
+  </div>
+</article>
+{{end}}

pkg/econet/econetui/templates/debug.html

@@ -0,0 +1 @@
+{{define "debug"}}{{.}}{{end}}

pkg/econet/econetui/templates/devices.html

@@ -0,0 +1,10 @@
+{{define "devices"}}
+  {{if .Devices}}
+    {{range .Devices}}{{template "card" .}}{{end}}
+  {{else}}
+    <article class="empty-state">
+      <p>No EcoNet devices loaded yet.</p>
+      <small>Device state populates after the first successful cloud poll.</small>
+    </article>
+  {{end}}
+{{end}}

pkg/econet/econetui/templates/layout.html

@@ -0,0 +1,57 @@
+{{define "layout"}}<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>EcoNet Admin</title>
+  <link rel="stylesheet" href="/static/pico.classless.min.css">
+  <link rel="stylesheet" href="/static/app.css">
+  <script src="/static/htmx.min.js" defer></script>
+  <script>
+    // Set the theme before first paint to avoid a flash.
+    (function () {
+      var saved = localStorage.getItem("theme");
+      var theme = saved || (window.matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light");
+      document.documentElement.setAttribute("data-theme", theme);
+    })();
+  </script>
+</head>
+<body>
+  <header class="app-header">
+    <hgroup>
+      <h1>EcoNet Admin</h1>
+      <p>Rheem water heater status &amp; control</p>
+    </hgroup>
+    <button id="theme-toggle" class="secondary theme-toggle" aria-label="Toggle dark mode" onclick="toggleTheme()"></button>
+  </header>
+
+  <main>
+    <div id="devices" class="device-grid" hx-get="/ui/devices" hx-trigger="every 30s" hx-swap="innerHTML">
+      {{template "devices" .}}
+    </div>
+  </main>
+
+  <dialog id="debug-modal" class="debug-modal">
+    <article>
+      <header>
+        <button aria-label="Close" rel="prev" onclick="document.getElementById('debug-modal').close()"></button>
+        <strong>Raw device JSON</strong>
+      </header>
+      <pre><code id="debug-modal-body">Loading…</code></pre>
+    </article>
+  </dialog>
+
+  <script>
+    function themeIcon(t) { return t === "dark" ? "☀️" : "🌙"; } // sun / moon
+    function toggleTheme() {
+      var cur = document.documentElement.getAttribute("data-theme");
+      var next = cur === "dark" ? "light" : "dark";
+      document.documentElement.setAttribute("data-theme", next);
+      localStorage.setItem("theme", next);
+      document.getElementById("theme-toggle").textContent = themeIcon(next);
+    }
+    document.getElementById("theme-toggle").textContent =
+      themeIcon(document.documentElement.getAttribute("data-theme"));
+  </script>
+</body>
+</html>{{end}}

pkg/econet/econetui/ui_test.go

@@ -0,0 +1,148 @@
+package econetui
+
+import (
+	"context"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
+)
+
+func newTestServer(t *testing.T) *EconetUIServer {
+	t.Helper()
+	// grpc is nil: the render/view helpers under test never touch it.
+	return NewEconetUIServer(context.Background(), &config.ServiceConfig{}, nil)
+}
+
+func sampleDevice() *pb.Device {
+	return &pb.Device{
+		SerialNumber:         "SN123",
+		FriendlyName:         "Garage Water Heater",
+		GenericType:          "heatpumpWaterHeater",
+		Connected:            true,
+		Mode:                 "energy-saving",
+		Running:              true,
+		RunningState:         "compressor-running",
+		Setpoint:             120,
+		HotWaterAvailability: 66,
+		AlertCount:           1,
+		SupportedModes: []pb.Mode{
+			pb.Mode_MODE_HEAT_PUMP,
+			pb.Mode_MODE_ENERGY_SAVING,
+			pb.Mode_MODE_HIGH_DEMAND,
+		},
+	}
+}
+
+func TestCardRendersWithPending(t *testing.T) {
+	s := newTestServer(t)
+	d := sampleDevice()
+
+	// Simulate an in-flight change to a mode different from the reported one.
+	s.pending.set(d.SerialNumber, "heat-pump")
+
+	cv := s.toCardView(d, true)
+	if cv.Pending != "Heat Pump" {
+		t.Fatalf("pending = %q, want %q", cv.Pending, "Heat Pump")
+	}
+	if cv.Icon != "/static/icons/heatpump.svg" {
+		t.Fatalf("icon = %q", cv.Icon)
+	}
+
+	rec := httptest.NewRecorder()
+	s.render(rec, "card", cv)
+	body := rec.Body.String()
+
+	for _, want := range []string{
+		`id="card-SN123"`,
+		"Garage Water Heater",
+		`hx-post="/ui/devices/SN123/mode"`,
+		"badge-pending",
+		"Updating", // "Updating → Heat Pump…"
+		"Energy Saving",
+		"Heat Pump",
+		"High Demand",
+		"120°F",
+		"66%",
+		"fill-meter", // fill-level graph
+		"fill-high",  // 66% → high bucket (>=66)
+	} {
+		if !strings.Contains(body, want) {
+			t.Errorf("card body missing %q\n---\n%s", want, body)
+		}
+	}
+}
+
+func TestCardConvergenceClearsPending(t *testing.T) {
+	s := newTestServer(t)
+	d := sampleDevice()
+	d.Mode = "heat-pump" // reported now matches the desired
+
+	s.pending.set(d.SerialNumber, "heat-pump")
+	cv := s.toCardView(d, true)
+
+	if cv.Pending != "" {
+		t.Fatalf("pending should clear once reported catches up, got %q", cv.Pending)
+	}
+	if _, ok := s.pending.get(d.SerialNumber); ok {
+		t.Fatalf("pending entry should have been removed after convergence")
+	}
+}
+
+func TestDevicesEmptyState(t *testing.T) {
+	s := newTestServer(t)
+	rec := httptest.NewRecorder()
+	s.render(rec, "devices", pageView{})
+	if !strings.Contains(rec.Body.String(), "No EcoNet devices loaded yet") {
+		t.Errorf("empty state not rendered:\n%s", rec.Body.String())
+	}
+}
+
+func TestIconForLoose(t *testing.T) {
+	cases := map[string]string{
+		"heatpumpWaterHeater":     "/static/icons/heatpump.svg",
+		"heatpumpWaterHeaterGen5": "/static/icons/heatpump.svg",
+		"HeatPump":                "/static/icons/heatpump.svg",
+		"Hybrid Electric":         "/static/icons/heatpump.svg",
+		"heat_pump_water_heater":  "/static/icons/heatpump.svg",
+		"gasWaterHeater":          "/static/icons/gas.svg",
+		"tanklessWaterHeater":     "/static/icons/tankless.svg",
+		"electricWaterHeater":     "/static/icons/electric.svg",
+		"somethingElse":           "/static/icons/unknown.svg",
+		"":                        "/static/icons/unknown.svg",
+	}
+	for in, want := range cases {
+		if got := iconFor(in); got != want {
+			t.Errorf("iconFor(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestDebugTemplateEscapes(t *testing.T) {
+	s := newTestServer(t)
+	rec := httptest.NewRecorder()
+	s.render(rec, "debug", `{"@NAME":"<b>x</b>"}`)
+	body := rec.Body.String()
+	if strings.Contains(body, "<b>") {
+		t.Errorf("debug output not escaped: %s", body)
+	}
+	if !strings.Contains(body, "&lt;b&gt;") {
+		t.Errorf("expected escaped JSON, got: %s", body)
+	}
+}
+
+func TestPrettyMode(t *testing.T) {
+	cases := map[string]string{
+		"heat-pump":     "Heat Pump",
+		"energy-saving": "Energy Saving",
+		"off":           "Off",
+		"":              "Unknown",
+	}
+	for in, want := range cases {
+		if got := prettyMode(in); got != want {
+			t.Errorf("prettyMode(%q) = %q, want %q", in, got, want)
+		}
+	}
+}

proto/econet/v1alpha1/econet.proto

@@ -28,6 +28,24 @@ message Device {
   int32 alert_count = 16;
   bool away = 17;
   google.protobuf.Timestamp last_updated = 18;
+  repeated Mode supported_modes = 19; // modes this device can be set to (may be empty)
+}
+
+// Mode is a settable operating mode for a water heater. The values mirror the
+// kebab-case slugs reported in Device.mode. Not every device supports every
+// mode; the supported set is device-specific (derived from the unit's reported
+// mode list), so SetMode validates against the target device.
+enum Mode {
+  MODE_UNSPECIFIED = 0;
+  MODE_OFF = 1;
+  MODE_ELECTRIC = 2;
+  MODE_ENERGY_SAVING = 3;
+  MODE_HEAT_PUMP = 4;
+  MODE_HIGH_DEMAND = 5;
+  MODE_GAS = 6;
+  MODE_PERFORMANCE = 7;
+  MODE_VACATION = 8;
+  MODE_ELECTRIC_GAS = 9; // combined electric/gas backup mode (e.g. hybrid units)
 }
 
 message ListDevicesRequest {}
@@ -44,6 +62,20 @@ message GetDeviceResponse {
   Device device = 1;
 }
 
+message SetModeRequest {
+  string serial_number = 1 [(buf.validate.field).string.min_len = 1];
+  Mode mode = 2 [(buf.validate.field).enum = {
+    defined_only: true
+    not_in: [0]
+  }];
+}
+
+message SetModeResponse {
+  // Last-known device state. The mode change is applied asynchronously by the
+  // Rheem cloud, so this reflects the requested mode only after a later poll.
+  Device device = 1;
+}
+
 // EconetService exposes read-only access to Rheem EcoNet device state.
 service EconetService {
   rpc ListDevices(ListDevicesRequest) returns (ListDevicesResponse) {
@@ -52,4 +84,10 @@ service EconetService {
   rpc GetDevice(GetDeviceRequest) returns (GetDeviceResponse) {
     option (google.api.http) = {get: "/v1alpha1/devices/{serial_number}"};
   }
+  rpc SetMode(SetModeRequest) returns (SetModeResponse) {
+    option (google.api.http) = {
+      post: "/v1alpha1/devices/{serial_number}/mode"
+      body: "*"
+    };
+  }
 }