Merge PR #66 : feat(web): name the house Szczepańcowa instead of Krosno

Merge PR #65 : docs(roadmap): the new gateway runs on the Pi with the inverters; D7 fixed
feat(web): name the house Szczepańcowa instead of Krosno
2026-10-24 11:29:22 +02:00 · 2026-10-24 11:29:22 +02:00 · 2026-10-24 11:26:55 +02:00 · 2026-10-24 11:25:28 +02:00 · 2026-10-24 11:13:20 +02:00 · 2026-10-24 11:11:09 +02:00
291 changed files with 23164 additions and 1358 deletions
@@ -0,0 +1,19 @@
+---
+name: close-milestone
+description: Close the current milestone in docs/roadmap.md, remove its working notes and start the next one. Use when every item of the current milestone is done.
+---
+
+# Close milestone
+
+1. Read `docs/roadmap.md`. Every item of "Current" is checked and its "Done when" holds.
+   Anything you cannot verify yourself (e.g. "a week on the Pi") you ask the user about.
+   Stop and report if something is open.
+2. Branch `docs/close-<milestone>` (e.g. `docs/close-m1`).
+3. Under "Done", add one line: `- M<n> <name> · <tag or commit>: <what it delivered>`.
+   Remove the "Current" checklist and any placeholder line.
+4. Remove the milestone's working notes: fixed defects (D…), consumed feasibility checks,
+   notes that served only this milestone. Verified knowledge moves first: controller facts
+   to `docs/frisko/`, scope or architecture to `docs/spec.md`, decisions to a new ADR.
+5. Make the next row of "Next" the new "Current": a checklist of PR-sized items in build
+   order, keeping its "Done when". Ask the user when the split is not obvious.
+6. `scripts/check.sh` (roadmap ≤ 80 lines), then `/ship`.
@@ -0,0 +1,31 @@
+---
+name: ship
+description: Take the current topic branch to master through a Gitea PR with green CI, then optionally release it and update the Pi. Use when a change is ready to merge or release.
+---
+
+# Ship
+
+Repo rules: `CONTRIBUTING.md`. Gitea: https://git.mariuszpacek.pl/mariusz.pacek/home-pump
+(no API token here; reads need none).
+
+1. On a topic branch (`feat/`, `fix/`, `docs/`, `chore/`, `refactor/`), clean tree, commits
+   in Conventional Commits. Run `scripts/check.sh`.
+2. `git push -u origin <branch>`; CI runs on every pushed branch.
+3. Open the PR by push (Gitea AGit), title in Conventional Commits, description says why:
+   `git push origin HEAD:refs/for/master -o topic=<branch> -o title="…" -o description="…"`.
+   The description is one line (push options cannot hold newlines). After later fixes push
+   both the branch and `refs/for/master` with the same topic, so CI and the PR both update.
+   If that is refused, give the user the compare link `…/compare/master...<branch>`.
+4. Wait for CI on the head commit, polling every 30 s:
+   `curl -s …/api/v1/repos/mariusz.pacek/home-pump/commits/<sha>/status` → `state`.
+   On `failure`, read the run under `…/actions`, fix, push again. Never merge red.
+5. Merge only if the user asked for it in this task:
+   `git switch master && git pull --ff-only && git merge --no-ff <branch> -m "Merge PR #N: <title>"`,
+   then `git push origin master` and delete the branch locally and on origin. Confirm CI is
+   green on master. Gitea does not close an AGit PR merged by hand: ask the user to close it.
+6. Release and update only with the user's explicit approval for this one:
+   `scripts/release.sh vMAJOR.MINOR.PATCH` (patch for fixes, minor for features) tags master;
+   wait until the Release run under `…/actions` is green (it publishes the images). Then on the
+   Pi (`ssh <host>`, an alias while D7 is open): `cd /home/pi/home-pump && ./update.sh <version>`,
+   watch `journalctl -t home-pump-gateway -f` and Grafana for one polling cycle (300 s) and
+   report what you saw. Backend and frontend reach Kraków through Arcane (homelab-compose).
@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - "**"
+
+jobs:
+  check:
+    name: Check (gateway, backend, frontend)
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Set up Java 21
+        uses: actions/setup-java@v5
+        with:
+          distribution: temurin
+          java-version: '21'
+      - name: Set up Maven
+        uses: stCarolas/setup-maven@v5
+        with:
+          maven-version: 3.9.6
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: '24'
+      - name: Check
+        run: scripts/check.sh
@@ -0,0 +1,56 @@
+# A pushed tag vMAJOR.MINOR.PATCH (scripts/release.sh) publishes the three images under that name
+# and as latest. The Pi pulls the gateway with gateway/update.sh; Kraków runs backend and frontend.
+name: Release
+
+on:
+  push:
+    tags:
+      - "v*.*.*"
+
+env:
+  REGISTRY: git.mariuszpacek.pl
+  IMAGES: git.mariuszpacek.pl/mariusz.pacek/home-pump
+
+jobs:
+  images:
+    name: Images
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      # As in homelab-upgrade: the job talks to VM103's daemon through the mounted socket.
+      - name: Docker CLI
+        run: command -v docker >/dev/null || (apt-get update -qq && apt-get install -y -qq docker.io >/dev/null); docker version --format '{{.Client.Version}} -> {{.Server.Version}}'
+      - name: Set up Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Log in to the Gitea registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ gitea.repository_owner }}
+          # The owner's token with package write access (the secret homelab-upgrade uses too).
+          password: ${{ secrets.REGISTRY_TOKEN }}
+      # The Pi is arm64. Each Dockerfile builds on the runner's platform and only copies into the
+      # final stage, so the arm64 image needs no emulation.
+      - name: Gateway
+        uses: docker/build-push-action@v6
+        with:
+          context: gateway
+          platforms: linux/arm64,linux/amd64
+          push: true
+          tags: ${{ env.IMAGES }}-gateway:${{ gitea.ref_name }},${{ env.IMAGES }}-gateway:latest
+      - name: Backend
+        uses: docker/build-push-action@v6
+        with:
+          context: backend
+          platforms: linux/amd64
+          push: true
+          tags: ${{ env.IMAGES }}-backend:${{ gitea.ref_name }},${{ env.IMAGES }}-backend:latest
+      - name: Frontend
+        uses: docker/build-push-action@v6
+        with:
+          context: frontend
+          platforms: linux/amd64
+          push: true
+          tags: ${{ env.IMAGES }}-frontend:${{ gitea.ref_name }},${{ env.IMAGES }}-frontend:latest
@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+# Enabled once per clone: git config core.hooksPath .githooks
+exec "$(git rev-parse --show-toplevel)/scripts/check.sh"
@@ -4,9 +4,10 @@
 .settings/

 # Intellij
-.idea/
+.idea
 *.iml
 *.iws
+.vscode

 # Mac
 .DS_Store
@@ -14,3 +15,46 @@
 # Maven
 log/
 target/
+/.idea/
+/.vscode/
+/.java-version
+dependency-reduced-pom.xml
+/workspace.code-workspace
+/target/
+
+# Node / frontend
+/node_modules/
+/frontend/node_modules/
+/frontend/dist/
+/dist/
+
+# Vite
+/.vite/
+
+# Env files
+.env
+.env.local
+.env.*.local
+
+# Logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+*.log
+logs/
+
+# Build / coverage
+build/
+coverage/
+
+# Misc
+.DS_Store
+
+# Large or legacy folders (not tracked)
+/apk/
+/old/
+/old_backup/
+
+# Agent worktrees
+/.claude/worktrees/
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-      <item class="javax.swing.JEditorPane" icon="/com/intellij/uiDesigner/icons/editorPane.png" removable="false" auto-create-binding="true" can-attach-label="true">
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-        <default-constraints vsize-policy="0" hsize-policy="2" anchor="8" fill="1" />
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-      <item class="javax.swing.JTable" icon="/com/intellij/uiDesigner/icons/table.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
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-      <item class="javax.swing.JList" icon="/com/intellij/uiDesigner/icons/list.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="6" hsize-policy="2" anchor="0" fill="3">
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-      </item>
-      <item class="javax.swing.JTree" icon="/com/intellij/uiDesigner/icons/tree.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3">
-          <preferred-size width="150" height="50" />
-        </default-constraints>
-      </item>
-      <item class="javax.swing.JTabbedPane" icon="/com/intellij/uiDesigner/icons/tabbedPane.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="3" hsize-policy="3" anchor="0" fill="3">
-          <preferred-size width="200" height="200" />
-        </default-constraints>
-      </item>
-      <item class="javax.swing.JSplitPane" icon="/com/intellij/uiDesigner/icons/splitPane.png" removable="false" auto-create-binding="false" can-attach-label="false">
-        <default-constraints vsize-policy="3" hsize-policy="3" anchor="0" fill="3">
-          <preferred-size width="200" height="200" />
-        </default-constraints>
-      </item>
-      <item class="javax.swing.JSpinner" icon="/com/intellij/uiDesigner/icons/spinner.png" removable="false" auto-create-binding="true" can-attach-label="true">
-        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1" />
-      </item>
-      <item class="javax.swing.JSlider" icon="/com/intellij/uiDesigner/icons/slider.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="0" hsize-policy="6" anchor="8" fill="1" />
-      </item>
-      <item class="javax.swing.JSeparator" icon="/com/intellij/uiDesigner/icons/separator.png" removable="false" auto-create-binding="false" can-attach-label="false">
-        <default-constraints vsize-policy="6" hsize-policy="6" anchor="0" fill="3" />
-      </item>
-      <item class="javax.swing.JProgressBar" icon="/com/intellij/uiDesigner/icons/progressbar.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="0" hsize-policy="6" anchor="0" fill="1" />
-      </item>
-      <item class="javax.swing.JToolBar" icon="/com/intellij/uiDesigner/icons/toolbar.png" removable="false" auto-create-binding="false" can-attach-label="false">
-        <default-constraints vsize-policy="0" hsize-policy="6" anchor="0" fill="1">
-          <preferred-size width="-1" height="20" />
-        </default-constraints>
-      </item>
-      <item class="javax.swing.JToolBar$Separator" icon="/com/intellij/uiDesigner/icons/toolbarSeparator.png" removable="false" auto-create-binding="false" can-attach-label="false">
-        <default-constraints vsize-policy="0" hsize-policy="0" anchor="0" fill="1" />
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-      <item class="javax.swing.JScrollBar" icon="/com/intellij/uiDesigner/icons/scrollbar.png" removable="false" auto-create-binding="true" can-attach-label="false">
-        <default-constraints vsize-policy="6" hsize-policy="0" anchor="0" fill="2" />
-      </item>
-    </group>
-  </component>
-</project>
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="" vcs="Git" />
-  </component>
-</project>
@@ -1,4 +0,0 @@
-{
-    "java.compile.nullAnalysis.mode": "automatic",
-    "java.configuration.updateBuildConfiguration": "automatic"
-}
@@ -0,0 +1,16 @@
+Backend for controlling the heat pump in Krosno (Frisko controller, Modbus TCP) from a phone.
+
+@CONTRIBUTING.md
+
+## For agents
+
+- Start from `docs/roadmap.md`; stay within the current milestone unless asked.
+- Read `docs/spec.md` and a decision in `docs/decisions/` only when the task touches it.
+- Production: `pi@raspberrypi.local`, the gateway in Docker (`gateway/compose.yaml`; until it is
+  installed, the old `home-pump.service`). Read-only inspection is fine; installing, updating,
+  restarting or changing files on the Pi needs explicit approval each time.
+- The Pi also runs `rpi-measurements.service` (house meter and BME280 into Influx); do not break
+  it. It moves into the gateway in M1; never run both against the meter at once. Do not upgrade
+  or reinstall the Pi's OS.
+- Never write to the controller `192.168.0.150` and never to the `Dom_Pompa` database.
+- Ask before force-pushing or rewriting history on Gitea.
@@ -0,0 +1,62 @@
+# Repository rules
+
+What we build: [docs/spec.md](docs/spec.md). Plan: [docs/roadmap.md](docs/roadmap.md).
+Reasons: [docs/decisions/](docs/decisions/).
+
+## Branches and pull requests
+
+- `master` is always deployable and matches what runs on the Pi.
+- Every change goes through a pull request on Gitea; no direct commits to `master`.
+- Branch names: `feat/…`, `fix/…`, `docs/…`, `chore/…`, `refactor/…`.
+- One topic per PR, small enough to review in one sitting. Merge only with green CI.
+- `archive/spring-boot-attempt` is reference only. Never merge it.
+
+## Commits
+
+- English, Conventional Commits: `fix(health): restart without /health polling`.
+- Imperative subject ≤ 72 characters; the body says why when it is not obvious.
+- Each commit builds and passes tests.
+
+## Code
+
+- Three parts, each with its `Dockerfile` and `compose.yaml` (ADR-010): `gateway/` and `backend/`
+  in Java 21 with Maven and no framework (ADR-001), `frontend/` in React and TypeScript (ADR-008).
+- `scripts/check.sh` is the gate: doc limits, secret scan, build and tests. CI runs it, and so
+  does the pre-push hook once enabled with `git config core.hooksPath .githooks`.
+- Readable first: small classes and methods, names from the domain, comments only for the why.
+- No dead code, no unused config, no duplicated logic, no speculative abstractions.
+- Every behaviour change has a test. Modbus is tested against `MockModbusServer` only.
+
+## Safety
+
+- Tests and local runs never use the real controller or the `Dom_Pompa` database.
+- A register is written only if it is on the allowlist (min, max, step) and verified in
+  `docs/frisko/`.
+- Changes to how or when we write to the controller need a test of the failure case.
+
+## Knowledge and docs
+
+Docs are written so an agent needs little context: read only what the task touches.
+
+| File | Limit | Changes |
+|---|---|---|
+| `CLAUDE.md` | 40 lines | rarely |
+| `docs/spec.md` | 120 lines | when scope or architecture changes |
+| `docs/roadmap.md` | 80 lines | every milestone |
+| `docs/decisions/NNN-*.md` | 40 lines | never after acceptance; supersede with a new ADR |
+| `docs/frisko/<topic>.md` | 120 lines | when knowledge is verified |
+| `<package>/CLAUDE.md` | 30 lines | rules of that layer |
+| `research/<source>/` | none | raw vendor material, kept as found; read only on demand |
+
+- Limits are checked by `scripts/check.sh`.
+- No status, audit or log documents: the state is git history and the roadmap.
+- Closing a milestone compresses it to one line in the roadmap and removes its working notes.
+- English everywhere; the UI is Polish.
+
+## Configuration, secrets, releases
+
+- No secrets in git. Production config lives on the Pi and next to the Kraków stacks, outside
+  the images.
+- Release only from `master` with `scripts/release.sh vMAJOR.MINOR.PATCH`: it tags master and
+  CI publishes the three images. On the Pi `./update.sh <version>` goes back if it is unhealthy.
+- After an update, watch the journal and Grafana for at least one polling cycle.
@@ -1,2 +1,25 @@
 # home-pump

+Heat pump (Frisko RX910-SE21) and home energy for the house in Krosno, from a phone.
+
+- What we build: [docs/spec.md](docs/spec.md)
+- Plan and current milestone: [docs/roadmap.md](docs/roadmap.md)
+- Rules for changes: [CONTRIBUTING.md](CONTRIBUTING.md)
+- Controller knowledge: [docs/frisko/](docs/frisko/rx910-se21.md)
+
+| Part | Runs | Readme |
+|---|---|---|
+| `gateway/` | Pi in Krosno, Docker: devices to InfluxDB, `/commands` | [gateway/README.md](gateway/README.md) |
+| `backend/` | Kraków, Docker: phone API | [backend/README.md](backend/README.md) |
+| `frontend/` | Kraków, Docker: web UI with nginx | [frontend/README.md](frontend/README.md) |
+
+Each part has its `Dockerfile` and `compose.yaml` (ADR-010).
+
+```bash
+scripts/check.sh                       # docs, secret scan, build and tests of all three parts
+git config core.hooksPath .githooks    # once per clone: check before every push
+scripts/release.sh vMAJOR.MINOR.PATCH  # tag master; CI publishes the three images in Gitea
+```
+
+After a release: on the Pi `./update.sh <version>` (gateway/README.md); in Kraków Arcane runs the
+backend and frontend images.
@@ -0,0 +1 @@
+target
@@ -0,0 +1,19 @@
+# Built on the build machine's own platform; the image only holds the jar and a JRE.
+FROM --platform=$BUILDPLATFORM maven:3.9-eclipse-temurin-21 AS build
+WORKDIR /src
+COPY pom.xml .
+RUN mvn -B -q dependency:go-offline
+COPY src src
+# Tests run in scripts/check.sh; some read contract files from gateway/, outside this context.
+RUN mvn -B -q package -Dmaven.test.skip=true
+
+FROM eclipse-temurin:21-jre-alpine
+USER 10001:10001
+WORKDIR /app
+COPY --from=build /src/target/home-pump-backend-1.0.0.jar app.jar
+EXPOSE 8080
+# /api/health answers 200 even while the gateway is unreachable (it reports that in the body),
+# so this only tells whether the backend itself serves requests. busybox wget ships with alpine.
+HEALTHCHECK --interval=30s --timeout=3s --start-period=10s \
+    CMD wget -q -O /dev/null "http://127.0.0.1:${PORT:-8080}/api/health" || exit 1
+ENTRYPOINT ["java", "-jar", "app.jar"]
@@ -0,0 +1,30 @@
+# Backend
+
+The phone API in Kraków (ADR-008): live state from the gateway, history from InfluxDB, setpoint
+changes passed to the gateway. JSON under `/api/` only; the web UI is the frontend's (ADR-010).
+The records in `home.backend.domain` and the examples in `src/test/resources/api/` are the contract.
+
+Settings are environment variables (`.env` next to `compose.yaml`); the backend refuses to start
+without the two URLs.
+Setpoint changes go only to the gateway; the user name from Traefik's `Remote-User` header (else `phone`) is sent as `X-Requested-By`.
+
+| Variable | Default | Meaning |
+|---|---|---|
+| `GATEWAY_URL` | required | the gateway on the Pi, e.g. `http://10.0.0.2:8080` |
+| `INFLUX_URL` | required | InfluxDB 1.x, e.g. `https://influxdb.example` |
+| `PORT` | `8080` | listening port |
+| `GATEWAY_TIMEOUT` | `5` | seconds |
+| `INFLUX_TIMEOUT` | `10` | seconds |
+| `GATEWAY_TOKEN` | unset | shared token for the gateway's `/commands`; without it the backend runs but `/api/setpoints` and `/api/presets/{id}` answer 503 |
+| `PRESETS_FILE` | built-in | JSON file replacing the presets: `[{"id", "name", "changes": [{"setpoint", "value", "hours"}]}]`, `hours` null means until changed; a bad file stops the start |
+
+```bash
+mvn -f backend/pom.xml clean package
+GATEWAY_URL=http://10.0.0.2:8080 INFLUX_URL=https://influxdb.example \
+  java -jar backend/target/home-pump-backend-1.0.0.jar        # API at http://localhost:8080/api/
+docker compose -f backend/compose.yaml up --build              # with backend/.env; network home-pump
+```
+
+Publish no host port in production: only the frontend, behind Traefik, may reach the backend. It
+trusts `Remote-User` and has no login of its own, so a direct port would bypass Traefik's access
+rules (ADR-009).
@@ -0,0 +1,16 @@
+# The backend in Kraków: the API only (ADR-010), reached by the frontend on the network home-pump
+# and published on no host port (ADR-009). Settings in .env next to this file (README).
+name: home-pump-backend
+services:
+  backend:
+    image: git.mariuszpacek.pl/mariusz.pacek/home-pump-backend:${VERSION:-latest}
+    build: .
+    restart: unless-stopped
+    env_file: .env
+    environment:
+      TZ: Europe/Warsaw
+    networks: [home-pump]
+
+networks:
+  home-pump:
+    name: home-pump
@@ -0,0 +1,84 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.home</groupId>
+    <artifactId>home-pump-backend</artifactId>
+    <version>1.0.0</version>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.release>21</maven.compiler.release>
+        <jackson.version>2.20.1</jackson.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <version>1.7.32</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.10.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>5.8.0</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.13.0</version>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.1.2</version>
+                <configuration>
+                    <redirectTestOutputToFile>true</redirectTestOutputToFile>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.4.1</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <createDependencyReducedPom>false</createDependencyReducedPom>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>home.backend.Main</mainClass>
+                                </transformer>
+                            </transformers>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>
@@ -0,0 +1,41 @@
+package home.backend;
+
+import home.backend.adapters.config.PresetFile;
+import home.backend.adapters.gateway.GatewayHttpClient;
+import home.backend.adapters.gateway.GatewayHttpCommands;
+import home.backend.adapters.http.ApiServer;
+import home.backend.adapters.influx.InfluxHistoryRepository;
+import home.backend.adapters.influx.InfluxSettings;
+import home.backend.application.EnergyService;
+import home.backend.application.HealthService;
+import home.backend.application.HeatPumpService;
+import home.backend.application.HistoryService;
+import home.backend.application.SetpointService;
+
+import java.io.IOException;
+import java.time.Clock;
+
+/** Wires the adapters and services together; the only place that knows all of them. */
+final class Backend {
+
+    private Backend() {
+    }
+
+    /**
+     * Binds the port but does not start serving.
+     *
+     * @throws IllegalArgumentException when PRESETS_FILE is unusable
+     */
+    static ApiServer assemble(Settings settings, Clock clock) throws IOException {
+        var gateway = new GatewayHttpClient(settings.gatewayUrl(), settings.gatewayTimeout());
+        var influx = new InfluxHistoryRepository(new InfluxSettings(settings.influxUrl(), settings.influxTimeout()));
+        var commands = new GatewayHttpCommands(settings.gatewayUrl(), settings.gatewayToken(),
+                settings.gatewayTimeout());
+        var setpoints = new SetpointService(commands, PresetFile.load(settings.presetsFile()));
+        return new ApiServer(settings.port(),
+                new HeatPumpService(gateway, clock),
+                new EnergyService(gateway, clock),
+                new HealthService(gateway, clock),
+                new HistoryService(influx, clock), setpoints);
+    }
+}
@@ -0,0 +1,31 @@
+package home.backend;
+
+import home.backend.adapters.http.ApiServer;
+
+import java.io.IOException;
+import java.time.Clock;
+
+public final class Main {
+
+    private Main() {
+    }
+
+    public static void main(String[] args) throws IOException {
+        Settings settings;
+        ApiServer server;
+        try {
+            settings = Settings.fromEnvironment(System.getenv());
+            server = Backend.assemble(settings, Clock.systemUTC());
+        } catch (IllegalArgumentException e) {
+            System.err.println("home-pump-backend: " + e.getMessage());
+            System.exit(2);
+            return;
+        }
+        if (settings.gatewayToken() == null) {
+            System.err.println("home-pump-backend: GATEWAY_TOKEN is not set, setpoint changes are disabled");
+        }
+        Runtime.getRuntime().addShutdownHook(new Thread(server::stop));
+        server.start();
+        System.out.println("home-pump-backend listening on port " + server.port());
+    }
+}
@@ -0,0 +1,65 @@
+package home.backend;
+
+import java.net.URI;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.util.Map;
+import java.util.Optional;
+
+/** Twelve-factor settings: everything comes from environment variables. */
+public record Settings(URI gatewayUrl, URI influxUrl, int port, Duration gatewayTimeout, Duration influxTimeout,
+        String gatewayToken, Path presetsFile) {
+
+    public static Settings fromEnvironment(Map<String, String> env) {
+        return new Settings(
+                url(env, "GATEWAY_URL"),
+                url(env, "INFLUX_URL"),
+                (int) number(env, "PORT", 8080, 0, 65535),
+                Duration.ofSeconds(number(env, "GATEWAY_TIMEOUT", 5, 1, 300)),
+                Duration.ofSeconds(number(env, "INFLUX_TIMEOUT", 10, 1, 300)),
+                optional(env, "GATEWAY_TOKEN"),
+                Optional.ofNullable(optional(env, "PRESETS_FILE")).map(Path::of).orElse(null));
+    }
+
+    /** Null when unset or blank. */
+    private static String optional(Map<String, String> env, String name) {
+        String value = env.get(name);
+        return value == null || value.isBlank() ? null : value.strip();
+    }
+
+    private static URI url(Map<String, String> env, String name) {
+        String value = env.get(name);
+        if (value == null || value.isBlank()) {
+            throw new IllegalArgumentException(name + " is required, e.g. " + name + "=http://host:8080");
+        }
+        URI uri = URI.create(value.strip());
+        if (uri.getHost() == null || !("http".equals(uri.getScheme()) || "https".equals(uri.getScheme()))) {
+            throw new IllegalArgumentException(name + " must be an http(s) URL with a host, got: " + value);
+        }
+        // The clients append their own paths to this base; a path here would be silently dropped or doubled.
+        boolean hasPath = !uri.getRawPath().isEmpty() && !uri.getRawPath().equals("/");
+        if (hasPath || uri.getRawQuery() != null || uri.getRawFragment() != null) {
+            throw new IllegalArgumentException(name + " must be only scheme, host and port, without a path, got: "
+                    + value);
+        }
+        return uri;
+    }
+
+    /** Timeouts are whole seconds. */
+    private static long number(Map<String, String> env, String name, long fallback, long min, long max) {
+        String value = env.get(name);
+        if (value == null || value.isBlank()) {
+            return fallback;
+        }
+        try {
+            long number = Long.parseLong(value.strip());
+            if (number >= min && number <= max) {
+                return number;
+            }
+        } catch (NumberFormatException e) {
+            // reported below with the same message
+        }
+        throw new IllegalArgumentException(name + " must be a whole number from " + min + " to " + max
+                + ", got: " + value);
+    }
+}
@@ -0,0 +1,41 @@
+package home.backend.adapters.config;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import home.backend.domain.Preset;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashSet;
+import java.util.List;
+
+/** Reads the presets (F3) from the optional PRESETS_FILE, else the built-in list. */
+public final class PresetFile {
+
+    private static final ObjectMapper JSON = new ObjectMapper();
+    private static final TypeReference<List<Preset>> PRESETS = new TypeReference<>() {
+    };
+
+    private PresetFile() {
+    }
+
+    /** @param file null for the built-in defaults; IllegalArgumentException when it is unusable */
+    public static List<Preset> load(Path file) {
+        String source = file == null ? "built-in presets" : "PRESETS_FILE " + file;
+        try (InputStream in = file == null ? defaults() : Files.newInputStream(file)) {
+            List<Preset> presets = JSON.readValue(in, PRESETS);
+            if (new HashSet<>(presets.stream().map(Preset::id).toList()).size() != presets.size()) {
+                throw new IllegalArgumentException("preset ids must be unique");
+            }
+            return presets;
+        } catch (IOException | IllegalArgumentException e) {
+            throw new IllegalArgumentException(source + " is not usable: " + e.getMessage(), e);
+        }
+    }
+
+    private static InputStream defaults() {
+        return PresetFile.class.getResourceAsStream("/presets-default.json");
+    }
+}
@@ -0,0 +1,88 @@
+package home.backend.adapters.gateway;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import home.backend.application.GatewayClient;
+import home.backend.domain.GatewaySnapshot;
+import home.backend.domain.GatewaySnapshot.DeviceSnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+/** Reads the gateway's {@code /health} and {@code /snapshot} over HTTP. */
+public class GatewayHttpClient implements GatewayClient {
+
+    private record Health(List<DeviceHealth> devices) {
+    }
+
+    private record DeviceHealth(String name, String status, Instant lastSuccess, String lastError) {
+    }
+
+    private record DeviceReadings(String name, List<Reading> readings) {
+    }
+
+    private record Reading(String database, String measurement, Map<String, Double> fields, Instant time) {
+    }
+
+    // Unknown properties are ignored so the gateway can add fields without breaking us.
+    private static final ObjectMapper JSON = new ObjectMapper()
+            .registerModule(new JavaTimeModule())
+            .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+    private final URI baseUri;
+    private final Duration timeout;
+    private final HttpClient http;
+
+    public GatewayHttpClient(URI baseUri, Duration timeout) {
+        this.baseUri = baseUri;
+        this.timeout = timeout;
+        this.http = HttpClient.newBuilder().connectTimeout(timeout).build();
+    }
+
+    @Override
+    public GatewaySnapshot snapshot() throws IOException {
+        var health = JSON.readValue(get("/health", true), Health.class);
+        var readings = JSON.readValue(get("/snapshot", false), DeviceReadings[].class);
+        Map<String, List<Measurement>> measurements = Arrays.stream(readings)
+                .collect(Collectors.toMap(DeviceReadings::name, GatewayHttpClient::measurements));
+        var devices = health.devices().stream()
+                .map(device -> new DeviceSnapshot(device.name(), device.status().equals("UP"),
+                        device.lastSuccess(), device.lastError(),
+                        measurements.getOrDefault(device.name(), List.of())))
+                .toList();
+        return new GatewaySnapshot(devices);
+    }
+
+    private static List<Measurement> measurements(DeviceReadings device) {
+        return device.readings().stream()
+                .map(r -> new Measurement(r.database(), r.measurement(), r.fields(), r.time()))
+                .toList();
+    }
+
+    /** A gateway with a device down answers /health with 503 and a valid body. */
+    private byte[] get(String path, boolean downIsValid) throws IOException {
+        var request = HttpRequest.newBuilder(baseUri.resolve(path)).timeout(timeout).GET().build();
+        try {
+            var response = http.send(request, HttpResponse.BodyHandlers.ofByteArray());
+            int status = response.statusCode();
+            if (status != 200 && !(downIsValid && status == 503)) {
+                throw new IOException("gateway " + path + " answered " + status);
+            }
+            return response.body();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("interrupted while calling gateway " + path, e);
+        }
+    }
+}
@@ -0,0 +1,81 @@
+package home.backend.adapters.gateway;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import home.backend.application.GatewayCommands;
+import home.backend.domain.Command;
+import home.backend.domain.CommandResult;
+import home.backend.domain.SetpointState;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.util.Set;
+
+/** Sends commands to the gateway's {@code /commands} with the shared token (S6). */
+public class GatewayHttpCommands implements GatewayCommands {
+
+    /** The gateway answers a verdict with 200 (applied), 422 (rejected) or 502 (failed). */
+    private static final Set<Integer> VERDICTS = Set.of(200, 422, 502);
+
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    private record Request(String setpoint, int value, Long minutes) {
+    }
+
+    private static final ObjectMapper JSON = new ObjectMapper()
+            .registerModule(new JavaTimeModule())
+            .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+    private final URI endpoint;
+    private final String token;
+    private final Duration timeout;
+    private final HttpClient http;
+
+    /** @param token null when not configured: every call then fails without touching the network */
+    public GatewayHttpCommands(URI baseUri, String token, Duration timeout) {
+        this.endpoint = baseUri.resolve("/commands");
+        this.token = token;
+        this.timeout = timeout;
+        this.http = HttpClient.newBuilder().connectTimeout(timeout).build();
+    }
+
+    @Override
+    public CommandResult apply(Command command) throws IOException {
+        Long minutes = command.duration() == null ? null : command.duration().toMinutes();
+        byte[] body = JSON.writeValueAsBytes(new Request(command.setpoint(), command.value(), minutes));
+        HttpRequest.Builder request = request().header("Content-Type", "application/json")
+                .header("X-Requested-By", command.requestedBy())
+                .POST(HttpRequest.BodyPublishers.ofByteArray(body));
+        return JSON.readValue(send(request, VERDICTS), CommandResult.class);
+    }
+
+    @Override
+    public SetpointState setpoints() throws IOException {
+        return JSON.readValue(send(request().GET(), Set.of(200)), SetpointState.class);
+    }
+
+    private HttpRequest.Builder request() throws IOException {
+        if (token == null) {
+            throw new IOException("GATEWAY_TOKEN is not set, commands are disabled");
+        }
+        return HttpRequest.newBuilder(endpoint).timeout(timeout).header("Authorization", "Bearer " + token);
+    }
+
+    private byte[] send(HttpRequest.Builder request, Set<Integer> accepted) throws IOException {
+        try {
+            var response = http.send(request.build(), HttpResponse.BodyHandlers.ofByteArray());
+            if (!accepted.contains(response.statusCode())) {
+                throw new IOException("gateway /commands answered " + response.statusCode());
+            }
+            return response.body();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("interrupted while calling gateway /commands", e);
+        }
+    }
+}
@@ -0,0 +1,280 @@
+package home.backend.adapters.http;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import com.sun.net.httpserver.HttpServer;
+import home.backend.application.EnergyService;
+import home.backend.application.HealthService;
+import home.backend.application.HeatPumpService;
+import home.backend.application.HistoryService;
+import home.backend.application.SetpointService;
+import home.backend.domain.CommandResult.Status;
+import home.backend.domain.PresetResult;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/** The phone-facing JSON API under {@code /api/} and the static web UI. */
+public class ApiServer {
+
+    private static final ObjectMapper JSON = new ObjectMapper()
+            .registerModule(new JavaTimeModule())
+            .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
+            // 45.5 or "45" must not silently become 45 in a request that writes to a heat pump.
+            .disable(DeserializationFeature.ACCEPT_FLOAT_AS_INT)
+            .disable(MapperFeature.ALLOW_COERCION_OF_SCALARS);
+
+    private record SetpointRequest(String setpoint, Integer value, Double hours) {
+    }
+
+    private static final String UNREACHABLE = "gateway unreachable";
+    private static final String WRITE_MARKER = "home-pump";
+    private static final String PRESETS_PATH = "/api/presets/";
+    /** The user name Traefik's auth forwards; anything odd falls back to the default. */
+    private static final String USER_HEADER = "Remote-User";
+    private static final String DEFAULT_USER = "phone";
+    private static final Pattern USER_NAME = Pattern.compile("[\\w.@+-]{1,64}");
+
+    private static final SecurityHeaders SECURITY_HEADERS = new SecurityHeaders();
+
+    /** A setpoint request is a few dozen bytes; anything near this is not from our UI. */
+    private static final int MAX_BODY_BYTES = 4096;
+    private static final int STOP_GRACE_SECONDS = 5;
+
+    private final HttpServer server;
+    private final ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
+
+    /** Binds the port now; 0 picks a free one. */
+    public ApiServer(int port, HeatPumpService heatPump, EnergyService energy, HealthService health,
+            HistoryService history, SetpointService setpoints) throws IOException {
+        server = HttpServer.create(new InetSocketAddress(port), 0);
+        server.setExecutor(executor);
+        // Everything outside the API, with the security headers too: the web UI is the frontend's (ADR-010).
+        context("/", exchange -> {
+            try (exchange) {
+                exchange.sendResponseHeaders(404, -1);
+            }
+        });
+        api("/api/heat-pump", query -> heatPump.current());
+        api("/api/energy", query -> energy.current());
+        api("/api/health", query -> health.current());
+        route("/api/history", exchange -> handleHistory(exchange, history));
+        route("/api/setpoints", exchange -> handle(exchange, Map.of(
+                "GET", () -> getSetpoints(exchange, setpoints),
+                "POST", () -> guarded(exchange, body -> postSetpoint(exchange, body, setpoints)))));
+        context(PRESETS_PATH, exchange -> handle(exchange, Map.of(
+                "POST", () -> guarded(exchange, body -> postPreset(exchange, setpoints)))));
+    }
+
+    /** The JDK matches a context by prefix, so /api/heat-pumpX would reach /api/heat-pump. */
+    private void route(String path, HttpHandler handler) {
+        context(path, exchange -> {
+            if (path.equals(exchange.getRequestURI().getPath())) {
+                handler.handle(exchange);
+            } else {
+                try (exchange) {
+                    exchange.sendResponseHeaders(404, -1);
+                }
+            }
+        });
+    }
+
+    private void context(String path, HttpHandler handler) {
+        server.createContext(path, handler).getFilters().add(SECURITY_HEADERS);
+    }
+
+    public void start() {
+        server.start();
+    }
+
+    public void stop() {
+        server.stop(STOP_GRACE_SECONDS);
+        executor.shutdown();
+    }
+
+    public int port() {
+        return server.getAddress().getPort();
+    }
+
+    private interface Gateway {
+        Object get(Map<String, String> query) throws IOException;
+    }
+
+    /** Gateway trouble on a live-state endpoint is the gateway being unreachable: 503. */
+    private void api(String path, Gateway gateway) {
+        route(path, exchange -> handle(exchange, Map.of("GET", () -> {
+            try {
+                send(exchange, 200, gateway.get(Map.of()));
+            } catch (IOException e) {
+                send(exchange, 503, error(UNREACHABLE));
+            }
+        })));
+    }
+
+    /**
+     * A page on another site can make the browser send a simple POST with the user's cookies. It cannot
+     * add a custom header, set a JSON content type or fake the Origin, so a write needs all three.
+     */
+    private static void guarded(HttpExchange exchange, Write write) throws IOException {
+        var headers = exchange.getRequestHeaders();
+        String origin = headers.getFirst("Origin");
+        if (origin != null && !origin.endsWith("//" + headers.getFirst("Host"))) {
+            send(exchange, 403, error("cross-site request"));
+        } else if (!WRITE_MARKER.equals(headers.getFirst("X-Requested-With"))) {
+            send(exchange, 403, error("missing X-Requested-With: " + WRITE_MARKER));
+        } else if (!isJson(headers.getFirst("Content-Type"))) {
+            send(exchange, 415, error("expected Content-Type: application/json"));
+        } else {
+            byte[] body = exchange.getRequestBody().readNBytes(MAX_BODY_BYTES + 1);
+            if (body.length > MAX_BODY_BYTES) {
+                send(exchange, 413, error("request body over " + MAX_BODY_BYTES + " bytes"));
+            } else {
+                write.run(body);
+            }
+        }
+    }
+
+    private static boolean isJson(String contentType) {
+        return contentType != null && contentType.split(";")[0].trim().equalsIgnoreCase("application/json");
+    }
+
+    private static void getSetpoints(HttpExchange exchange, SetpointService setpoints) throws IOException {
+        try {
+            send(exchange, 200, setpoints.current());
+        } catch (IOException e) {
+            send(exchange, 503, error(UNREACHABLE));
+        }
+    }
+
+    private static void postSetpoint(HttpExchange exchange, byte[] body, SetpointService setpoints)
+            throws IOException {
+        try {
+            var request = JSON.readValue(body, SetpointRequest.class);
+            if (request == null || request.setpoint() == null || request.value() == null) {
+                throw new IllegalArgumentException("setpoint and value are required");
+            }
+            var result = setpoints.apply(request.setpoint(), request.value(), request.hours(), user(exchange));
+            send(exchange, httpStatus(result.status()), result);
+        } catch (JsonProcessingException | IllegalArgumentException e) {
+            send(exchange, 400, error("expected {\"setpoint\", \"value\", \"hours\"?}"));
+        } catch (IOException e) {
+            send(exchange, 503, error(UNREACHABLE));
+        }
+    }
+
+    private static void postPreset(HttpExchange exchange, SetpointService setpoints) throws IOException {
+        String id = exchange.getRequestURI().getPath().substring(PRESETS_PATH.length());
+        try {
+            var result = setpoints.applyPreset(id, user(exchange));
+            if (result.isPresent()) {
+                send(exchange, presetHttpStatus(result.get().status()), result.get());
+            } else {
+                send(exchange, 404, error("no such preset"));
+            }
+        } catch (IOException e) {
+            send(exchange, 503, error(UNREACHABLE));
+        }
+    }
+
+    private static int httpStatus(Status status) {
+        return switch (status) {
+            case APPLIED -> 200;
+            case REJECTED -> 422;
+            case FAILED -> 502;
+        };
+    }
+
+    private static int presetHttpStatus(PresetResult.Status status) {
+        return switch (status) {
+            case APPLIED -> 200;
+            case REJECTED -> 422;
+            case FAILED, PARTIAL -> 502;
+        };
+    }
+
+    private static String user(HttpExchange exchange) {
+        String name = exchange.getRequestHeaders().getFirst(USER_HEADER);
+        return name != null && USER_NAME.matcher(name).matches() ? name : DEFAULT_USER;
+    }
+
+    private void handleHistory(HttpExchange exchange, HistoryService history) throws IOException {
+        handle(exchange, Map.of("GET", () -> {
+            Map<String, String> query = parseQuery(exchange.getRequestURI().getRawQuery());
+            try {
+                send(exchange, 200, history.history(query.get("series"), query.get("range")));
+            } catch (IllegalArgumentException e) {
+                send(exchange, 400, error(e.getMessage()));
+            } catch (IOException e) {
+                send(exchange, 502, error("history unavailable"));
+            }
+        }));
+    }
+
+    private interface Action {
+        void run() throws IOException;
+    }
+
+    private interface Write {
+        void run(byte[] body) throws IOException;
+    }
+
+    private static void handle(HttpExchange exchange, Map<String, Action> byMethod) throws IOException {
+        try (exchange) {
+            Action action = byMethod.get(exchange.getRequestMethod());
+            if (action == null) {
+                exchange.sendResponseHeaders(405, -1);
+                return;
+            }
+            try {
+                action.run();
+            } catch (RuntimeException e) {
+                // A gateway payload the client could not map (duplicate device, missing status): answer, do not drop.
+                System.err.println("home-pump-backend: " + exchange.getRequestURI().getPath() + ": " + e);
+                if (exchange.getResponseCode() == -1) {
+                    send(exchange, 502, error("bad gateway response"));
+                }
+            }
+        }
+    }
+
+    private static void send(HttpExchange exchange, int status, Object body) throws IOException {
+        byte[] bytes = JSON.writeValueAsBytes(body);
+        exchange.getResponseHeaders().set("Content-Type", "application/json");
+        exchange.getResponseHeaders().set("Cache-Control", "no-store");
+        exchange.sendResponseHeaders(status, bytes.length);
+        exchange.getResponseBody().write(bytes);
+    }
+
+    private static Map<String, String> error(String message) {
+        return Map.of("error", message);
+    }
+
+    private static Map<String, String> parseQuery(String raw) {
+        Map<String, String> query = new HashMap<>();
+        if (raw == null) {
+            return query;
+        }
+        for (String pair : raw.split("&")) {
+            String[] kv = pair.split("=", 2);
+            query.put(decode(kv[0]), kv.length == 2 ? decode(kv[1]) : "");
+        }
+        return query;
+    }
+
+    private static String decode(String s) {
+        return URLDecoder.decode(s, StandardCharsets.UTF_8);
+    }
+}
@@ -0,0 +1,28 @@
+package home.backend.adapters.http;
+
+import com.sun.net.httpserver.Filter;
+import com.sun.net.httpserver.HttpExchange;
+
+import java.io.IOException;
+
+/** Sets the browser hardening headers on every response, whatever handler answers. */
+final class SecurityHeaders extends Filter {
+
+    private static final String POLICY = "default-src 'none'; script-src 'self'; style-src 'self'; "
+            + "img-src 'self' data:; font-src 'self'; connect-src 'self'; base-uri 'none'; "
+            + "form-action 'self'; frame-ancestors 'none'";
+
+    @Override
+    public void doFilter(HttpExchange exchange, Chain chain) throws IOException {
+        var headers = exchange.getResponseHeaders();
+        headers.set("Content-Security-Policy", POLICY);
+        headers.set("X-Content-Type-Options", "nosniff");
+        headers.set("Referrer-Policy", "no-referrer");
+        chain.doFilter(exchange);
+    }
+
+    @Override
+    public String description() {
+        return "security headers";
+    }
+}
@@ -0,0 +1,95 @@
+package home.backend.adapters.influx;
+
+import home.backend.application.HistoryRepository;
+import home.backend.domain.HistoryView.Point;
+import home.backend.domain.Series;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URLEncoder;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+
+/** History from InfluxDB 1.x over its HTTP {@code /query} endpoint (ADR-005, ADR-008). */
+public final class InfluxHistoryRepository implements HistoryRepository {
+
+    private final InfluxSettings settings;
+    private final HttpClient http;
+
+    public InfluxHistoryRepository(InfluxSettings settings) {
+        this.settings = settings;
+        this.http = HttpClient.newBuilder().connectTimeout(settings.requestTimeout()).build();
+    }
+
+    @Override
+    public List<Point> history(Series series, Instant from, Instant to, int maxPoints) throws IOException {
+        if (maxPoints < 1 || !from.isBefore(to)) {
+            throw new IllegalArgumentException("need maxPoints >= 1 and from < to");
+        }
+        long stepMinutes = stepMinutes(from, to, maxPoints);
+        Map<Long, Double> summed = new TreeMap<>();
+        try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
+            var parts = SeriesSources.of(series).stream()
+                    .map(source -> executor.submit(() -> part(source, from, to, stepMinutes)))
+                    .toList();
+            // Summed in source order, so the result does not depend on which answer comes first.
+            for (var part : parts) {
+                // A part without data is absent, not zero, so a bucket is kept if any part has it.
+                part.get().forEach((t, v) -> summed.merge(t, v, Double::sum));
+            }
+        } catch (ExecutionException e) {
+            throw e.getCause() instanceof IOException io ? io : new IOException(e.getCause());
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("InfluxDB request interrupted", e);
+        }
+        return summed.entrySet().stream()
+                .map(e -> new Point(Instant.ofEpochMilli(e.getKey()), e.getValue()))
+                .toList();
+    }
+
+    private Map<Long, Double> part(Source source, Instant from, Instant to, long stepMinutes) throws IOException {
+        String query = source.query(from.toEpochMilli(), to.toEpochMilli(), stepMinutes);
+        return InfluxResponse.parse(fetch(source.database(), query));
+    }
+
+    private static long stepMinutes(Instant from, Instant to, int maxPoints) {
+        long stepMillis = Math.ceilDiv(Duration.between(from, to).toMillis(), maxPoints);
+        return Math.max(1, Math.ceilDiv(stepMillis, Duration.ofMinutes(1).toMillis()));
+    }
+
+    private String fetch(String database, String query) throws IOException {
+        HttpRequest request = HttpRequest.newBuilder(queryUri(database, query))
+                .timeout(settings.requestTimeout())
+                .GET()
+                .build();
+        try {
+            HttpResponse<String> response = http.send(request, HttpResponse.BodyHandlers.ofString());
+            if (response.statusCode() != 200) {
+                throw new IOException("InfluxDB answered HTTP " + response.statusCode());
+            }
+            return response.body();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("InfluxDB request interrupted", e);
+        }
+    }
+
+    private URI queryUri(String database, String query) {
+        String base = settings.baseUri().toString().replaceAll("/+$", "");
+        return URI.create(base + "/query?db=" + encode(database) + "&epoch=ms&q=" + encode(query));
+    }
+
+    private static String encode(String value) {
+        return URLEncoder.encode(value, StandardCharsets.UTF_8);
+    }
+}
@@ -0,0 +1,50 @@
+package home.backend.adapters.influx;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.TreeMap;
+
+/** The {@code time, mean} rows of an InfluxDB 1.x query response. */
+final class InfluxResponse {
+
+    private static final ObjectMapper JSON = new ObjectMapper();
+
+    private InfluxResponse() {
+    }
+
+    /** Mean per bucket start in epoch milliseconds, ascending; empty when there is no data. */
+    static Map<Long, Double> parse(String body) throws IOException {
+        JsonNode root = read(body);
+        failOnError(root);
+        Map<Long, Double> means = new TreeMap<>();
+        for (JsonNode result : root.path("results")) {
+            failOnError(result);
+            for (JsonNode series : result.path("series")) {
+                for (JsonNode row : series.path("values")) {
+                    if (row.size() >= 2 && row.get(1).isNumber()) {
+                        means.put(row.get(0).asLong(), row.get(1).asDouble());
+                    }
+                }
+            }
+        }
+        return means;
+    }
+
+    private static JsonNode read(String body) throws IOException {
+        try {
+            return JSON.readTree(body);
+        } catch (JsonProcessingException e) {
+            throw new IOException("InfluxDB returned invalid JSON: " + e.getOriginalMessage(), e);
+        }
+    }
+
+    private static void failOnError(JsonNode node) throws IOException {
+        if (node.hasNonNull("error")) {
+            throw new IOException("InfluxDB query failed: " + node.get("error").asText());
+        }
+    }
+}
@@ -0,0 +1,7 @@
+package home.backend.adapters.influx;
+
+import java.net.URI;
+import java.time.Duration;
+
+public record InfluxSettings(URI baseUri, Duration requestTimeout) {
+}
@@ -0,0 +1,44 @@
+package home.backend.adapters.influx;
+
+import home.backend.domain.Series;
+
+import java.util.List;
+import java.util.Map;
+
+/** Where each series lives in InfluxDB. A fixed table: no query is built from user input. */
+final class SeriesSources {
+
+    private static final String LEGACY = "Dom_Pompa";
+    private static final String ELECTRICITY = "electricity";
+
+    private static final Map<Series, List<Source>> SOURCES = Map.ofEntries(
+            Map.entry(Series.OUTDOOR_TEMP, List.of(pompa("External temperature"))),
+            Map.entry(Series.INDOOR_TEMP, List.of(pompa("Temp wew"))),
+            Map.entry(Series.CO_BUFFER_TEMP, List.of(pompa("Temp co"))),
+            Map.entry(Series.CWU_TEMP, List.of(pompa("Temp cwu"))),
+            Map.entry(Series.GROUND_IN_TEMP, List.of(pompa("Temp in"))),
+            Map.entry(Series.GROUND_OUT_TEMP, List.of(pompa("Temp out"))),
+            Map.entry(Series.PUMP_OUTLET_TEMP, List.of(pompa("Temp pc out"))),
+            Map.entry(Series.GRID_POWER, List.of(electricity("PRAD2", "total_power_active"))),
+            Map.entry(Series.PV_POWER, List.of(
+                    electricity("deye", "pv1_power_w"),
+                    electricity("deye", "pv2_power_w"),
+                    electricity("fronius", "pv_power_w"))),
+            Map.entry(Series.LOAD_POWER, List.of(electricity("deye", "load_power_w"))),
+            Map.entry(Series.BATTERY_SOC, List.of(electricity("deye", "battery_soc_pct"))));
+
+    private SeriesSources() {
+    }
+
+    static List<Source> of(Series series) {
+        return SOURCES.get(series);
+    }
+
+    private static Source pompa(String field) {
+        return new Source(LEGACY, "POMPA", field);
+    }
+
+    private static Source electricity(String measurement, String field) {
+        return new Source(ELECTRICITY, measurement, field);
+    }
+}
@@ -0,0 +1,15 @@
+package home.backend.adapters.influx;
+
+/** One field of one measurement; the parts of a series are summed. */
+record Source(String database, String measurement, String field) {
+
+    String query(long fromMs, long toMs, long stepMinutes) {
+        return "SELECT mean(" + quote(field) + ") FROM " + quote(measurement)
+                + " WHERE time >= " + fromMs + "ms AND time < " + toMs + "ms"
+                + " GROUP BY time(" + stepMinutes + "m) fill(none)";
+    }
+
+    private static String quote(String identifier) {
+        return '"' + identifier.replace("\\", "\\\\").replace("\"", "\\\"") + '"';
+    }
+}
@@ -0,0 +1,69 @@
+package home.backend.application;
+
+import home.backend.domain.EnergyView;
+import home.backend.domain.EnergyView.Source;
+import home.backend.domain.EnergyView.Today;
+import home.backend.domain.GatewaySnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+/** F7: house electricity from the Deye inverter and the Fronius PV inverter. */
+public class EnergyService {
+
+    /** One inverter's fields; empty when it is stale, so nothing old is shown as current. */
+    private record Inverter(Source source, Map<String, Double> fields) {
+    }
+
+    private final GatewayClient gateway;
+    private final Clock clock;
+
+    public EnergyService(GatewayClient gateway, Clock clock) {
+        this.gateway = gateway;
+        this.clock = clock;
+    }
+
+    public EnergyView current() throws IOException {
+        GatewaySnapshot snapshot = gateway.snapshot();
+        Inverter deye = inverter(snapshot, "deye");
+        Inverter fronius = inverter(snapshot, "fronius");
+        Map<String, Double> d = deye.fields();
+        Map<String, Double> f = fronius.fields();
+
+        Double froniusKwh = f.containsKey("energy_day_wh") ? f.get("energy_day_wh") / 1000 : null;
+        Today today = new Today(round(sum(d.get("pv_today_kwh"), froniusKwh)),
+                d.get("grid_bought_today_kwh"), d.get("grid_sold_today_kwh"), d.get("load_today_kwh"));
+        List<Source> sources = List.of(deye.source(), fronius.source());
+        return new EnergyView(oldest(sources), sources,
+                sum(d.get("pv1_power_w"), d.get("pv2_power_w"), f.get("pv_power_w")),
+                d.get("grid_power_w"), d.get("battery_power_w"), d.get("battery_soc_pct"),
+                d.get("load_power_w"), today);
+    }
+
+    private Inverter inverter(GatewaySnapshot snapshot, String name) {
+        Optional<Measurement> reading = SnapshotFields.find(snapshot, name, name);
+        boolean stale = SnapshotFields.stale(SnapshotFields.device(snapshot, name), reading, clock.instant());
+        Source source = new Source(name, reading.map(Measurement::time).orElse(null), stale);
+        return new Inverter(source, stale ? Map.of() : reading.get().fields());
+    }
+
+    private static Instant oldest(List<Source> sources) {
+        return sources.stream().map(Source::time).flatMap(Stream::ofNullable).min(Instant::compareTo).orElse(null);
+    }
+
+    /** Sum of the values that exist; null when none does. */
+    private static Double sum(Double... values) {
+        return Stream.of(values).filter(v -> v != null).reduce(Double::sum).orElse(null);
+    }
+
+    /** Wh to kWh leaves binary noise such as 34.300000000000004. */
+    private static Double round(Double kwh) {
+        return kwh == null ? null : Math.round(kwh * 1000) / 1000.0;
+    }
+}
@@ -0,0 +1,11 @@
+package home.backend.application;
+
+import home.backend.domain.GatewaySnapshot;
+
+import java.io.IOException;
+
+/** The live state, read from the gateway on the Pi through the tunnel. */
+public interface GatewayClient {
+
+    GatewaySnapshot snapshot() throws IOException;
+}
@@ -0,0 +1,16 @@
+package home.backend.application;
+
+import home.backend.domain.Command;
+import home.backend.domain.CommandResult;
+import home.backend.domain.SetpointState;
+
+import java.io.IOException;
+
+/** The only way the backend writes anything: through the gateway, which checks every command. */
+public interface GatewayCommands {
+
+    /** A verdict, even a negative one; IOException only when no verdict could be obtained. */
+    CommandResult apply(Command command) throws IOException;
+
+    SetpointState setpoints() throws IOException;
+}
@@ -0,0 +1,35 @@
+package home.backend.application;
+
+import home.backend.domain.GatewaySnapshot.DeviceSnapshot;
+import home.backend.domain.HealthView;
+import home.backend.domain.HealthView.DeviceHealth;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.util.List;
+
+/** F5: whether the gateway answers and which device links are up. */
+public class HealthService {
+
+    private final GatewayClient gateway;
+    private final Clock clock;
+
+    public HealthService(GatewayClient gateway, Clock clock) {
+        this.gateway = gateway;
+        this.clock = clock;
+    }
+
+    public HealthView current() {
+        try {
+            List<DeviceHealth> devices = gateway.snapshot().devices().stream()
+                    .map(HealthService::health).toList();
+            return new HealthView(clock.instant(), true, devices);
+        } catch (IOException e) {
+            return new HealthView(clock.instant(), false, List.of());
+        }
+    }
+
+    private static DeviceHealth health(DeviceSnapshot d) {
+        return new DeviceHealth(d.name(), d.up(), d.lastSuccess(), d.lastError());
+    }
+}
@@ -0,0 +1,87 @@
+package home.backend.application;
+
+import home.backend.domain.GatewaySnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+import home.backend.domain.HeatPumpView;
+import home.backend.domain.HeatPumpView.Pumps;
+import home.backend.domain.HeatPumpView.Setpoints;
+import home.backend.domain.HeatPumpView.State;
+import home.backend.domain.HeatPumpView.Targets;
+import home.backend.domain.HeatPumpView.Temperatures;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.time.Instant;
+import java.util.Map;
+import java.util.Optional;
+
+import static home.backend.application.SnapshotFields.on;
+import static home.backend.application.SnapshotFields.whole;
+
+/** F1: the heat pump's live state from the gateway's {@code heat_pump} measurement. */
+public class HeatPumpService {
+
+    private static final String DATABASE = "Dom_Pompa";
+    private static final State[] STATES = State.values();
+
+    private final GatewayClient gateway;
+    private final Clock clock;
+
+    public HeatPumpService(GatewayClient gateway, Clock clock) {
+        this.gateway = gateway;
+        this.clock = clock;
+    }
+
+    public HeatPumpView current() throws IOException {
+        GatewaySnapshot snapshot = gateway.snapshot();
+        Optional<Measurement> reading = SnapshotFields.find(snapshot, "heat-pump", "heat_pump")
+                .filter(m -> DATABASE.equals(m.database()));
+        boolean stale = SnapshotFields.stale(SnapshotFields.device(snapshot, "heat-pump"), reading, clock.instant());
+        return view(reading.map(Measurement::time).orElse(null), stale,
+                reading.map(Measurement::fields).orElse(Map.of()));
+    }
+
+    private static HeatPumpView view(Instant time, boolean stale, Map<String, Double> f) {
+        Integer alarmCode = whole(f, "alarm_code");
+        return new HeatPumpView(time, stale, state(f), whole(f, "output_compressor"), on(f, "output_heater"),
+                on(f, "alarm") || on(f, "alarm_code"), alarmCode, alarmText(alarmCode),
+                new Pumps(on(f, "output_co"), on(f, "output_buffer"), on(f, "output_circulation"),
+                        on(f, "output_ground"), on(f, "output_cwu")),
+                new Temperatures(tenths(f, "outdoor_temp"), tenths(f, "indoor_temp"),
+                        tenths(f, "co_buffer_temp"), tenths(f, "cwu_temp"), tenths(f, "ground_in_temp"),
+                        tenths(f, "ground_out_temp"), tenths(f, "pump_outlet_temp"),
+                        tenths(f, "outdoor_avg_temp")),
+                new Targets(tenths(f, "target_room_temp"), tenths(f, "target_co_temp"),
+                        tenths(f, "target_cwu_temp")),
+                new Setpoints(whole(f, "setpoint_co_economy"), whole(f, "setpoint_co_comfort"),
+                        whole(f, "setpoint_cwu_economy"), whole(f, "setpoint_cwu_comfort")));
+    }
+
+    /** Codes of register 4011 as the vendor app names them; unverified on our device. */
+    private static String alarmText(Integer code) {
+        if (code == null || code == 0) {
+            return null;
+        }
+        return switch (code) {
+            case 2 -> "Usterka czujnika temperatury zewnętrznej";
+            case 3 -> "Usterka czujnika temperatury CO";
+            case 4 -> "Usterka czujnika temperatury wewnętrznej";
+            case 5 -> "Usterka czujnika temperatury CWU";
+            case 14 -> "Usterka czujnika temperatury wyjścia pompy";
+            case 15 -> "Usterka czujnika temperatury dolnego źródła";
+            case 1003 -> "Zadziałał presostat (ciśnienie)";
+            default -> "Kod usterki " + code;
+        };
+    }
+
+    /** The controller resolves 0.1 °C; the gateway's 212 * 0.1 is 21.200000000000003. */
+    private static Double tenths(Map<String, Double> fields, String name) {
+        Double value = fields.get(name);
+        return value == null ? null : Math.round(value * 10) / 10.0;
+    }
+
+    private static State state(Map<String, Double> f) {
+        Integer mode = whole(f, "pump_mode");
+        return mode == null || mode < 0 || mode >= STATES.length ? null : STATES[mode];
+    }
+}
@@ -0,0 +1,14 @@
+package home.backend.application;
+
+import home.backend.domain.HistoryView.Point;
+import home.backend.domain.Series;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.List;
+
+/** Past values from InfluxDB, averaged into about {@code maxPoints} steps. */
+public interface HistoryRepository {
+
+    List<Point> history(Series series, Instant from, Instant to, int maxPoints) throws IOException;
+}
@@ -0,0 +1,43 @@
+package home.backend.application;
+
+import home.backend.domain.HistoryView;
+import home.backend.domain.Series;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Map;
+
+/** F2: one series over the last 24 hours or 7 days. */
+public class HistoryService {
+
+    static final int MAX_POINTS = 300;
+    private static final String DEFAULT_RANGE = "24h";
+    private static final Map<String, Duration> RANGES =
+            Map.of("24h", Duration.ofHours(24), "7d", Duration.ofDays(7));
+
+    private final HistoryRepository repository;
+    private final Clock clock;
+
+    public HistoryService(HistoryRepository repository, Clock clock) {
+        this.repository = repository;
+        this.clock = clock;
+    }
+
+    /**
+     * @param range {@code 24h} or {@code 7d}; null means 24h
+     * @throws IllegalArgumentException for an unknown series or range
+     */
+    public HistoryView history(String seriesId, String range) throws IOException {
+        Series series = Series.fromId(seriesId)
+                .orElseThrow(() -> new IllegalArgumentException("unknown series: " + seriesId));
+        Duration length = RANGES.get(range == null ? DEFAULT_RANGE : range);
+        if (length == null) {
+            throw new IllegalArgumentException("unknown range: " + range);
+        }
+        Instant to = clock.instant();
+        return new HistoryView(series.id(), series.unit(),
+                repository.history(series, to.minus(length), to, MAX_POINTS));
+    }
+}
@@ -0,0 +1,104 @@
+package home.backend.application;
+
+import home.backend.domain.Command;
+import home.backend.domain.CommandResult;
+import home.backend.domain.Preset;
+import home.backend.domain.Preset.Change;
+import home.backend.domain.PresetResult;
+import home.backend.domain.PresetResult.ChangeResult;
+import home.backend.domain.PresetResult.ChangeStatus;
+import home.backend.domain.Setpoint;
+import home.backend.domain.SetpointState;
+import home.backend.domain.SetpointsView;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+/** F3: change setpoints directly or through a preset; the gateway enforces the limits (S1). */
+public class SetpointService {
+
+    private final GatewayCommands gateway;
+    private final List<Preset> presets;
+
+    public SetpointService(GatewayCommands gateway, List<Preset> presets) {
+        this.gateway = gateway;
+        this.presets = List.copyOf(presets);
+    }
+
+    public SetpointsView current() throws IOException {
+        SetpointState state = gateway.setpoints();
+        return new SetpointsView(state.setpoints(), state.restores(), presets);
+    }
+
+    /** @param hours how long to keep the value, null until changed back */
+    public CommandResult apply(String setpoint, int value, Double hours, String user) throws IOException {
+        return gateway.apply(new Command(setpoint, value, duration(hours), user));
+    }
+
+    /**
+     * Empty if there is no such preset. A preset that does not fit the gateway's limits writes nothing.
+     * IOException only when no change was attempted; once writing starts, trouble is reported per change.
+     */
+    public Optional<PresetResult> applyPreset(String id, String user) throws IOException {
+        Optional<Preset> preset = presets.stream().filter(p -> p.id().equals(id)).findFirst();
+        if (preset.isEmpty()) {
+            return Optional.empty();
+        }
+        List<Change> changes = preset.get().changes();
+        List<Setpoint> limits = gateway.setpoints().setpoints();
+        List<ChangeResult> checked = changes.stream().map(c -> check(c, limits)).toList();
+        if (checked.stream().anyMatch(r -> r.status() == ChangeStatus.REJECTED)) {
+            return Optional.of(PresetResult.of(checked));
+        }
+        return Optional.of(PresetResult.of(run(changes, user)));
+    }
+
+    private List<ChangeResult> run(List<Change> changes, String user) {
+        List<ChangeResult> results = new ArrayList<>();
+        for (Change change : changes) {
+            boolean stopped = !results.isEmpty() && results.getLast().status() != ChangeStatus.APPLIED;
+            results.add(stopped ? ChangeResult.notAttempted() : attempt(change, user));
+        }
+        return results;
+    }
+
+    private ChangeResult attempt(Change change, String user) {
+        try {
+            return ChangeResult.of(apply(change.setpoint(), change.value(), change.hours(), user));
+        } catch (IOException e) {
+            return new ChangeResult(ChangeStatus.UNKNOWN, "no answer from the gateway", null);
+        }
+    }
+
+    /** REJECTED with the reason, or NOT_ATTEMPTED (nothing is sent if any change is rejected). */
+    private static ChangeResult check(Change change, List<Setpoint> limits) {
+        String problem = problem(change, limits);
+        return problem == null ? ChangeResult.notAttempted() : new ChangeResult(ChangeStatus.REJECTED, problem, null);
+    }
+
+    private static String problem(Change change, List<Setpoint> limits) {
+        Optional<Setpoint> known = limits.stream().filter(s -> s.name().equals(change.setpoint())).findFirst();
+        if (known.isEmpty()) {
+            return "preset sets " + change.setpoint() + ", which the gateway does not know";
+        }
+        if (!known.get().allows(change.value())) {
+            return "preset sets " + change.setpoint() + " to " + change.value() + ", outside the gateway's limits "
+                    + known.get().min() + "–" + known.get().max() + " step " + known.get().step();
+        }
+        return null;
+    }
+
+    private static Duration duration(Double hours) {
+        if (hours == null) {
+            return null;
+        }
+        long minutes = Math.round(hours * 60);
+        if (minutes < 1 || minutes > Command.MAX_HOURS * 60L) {
+            throw new IllegalArgumentException("hours must be from one minute to " + Command.MAX_HOURS + " hours");
+        }
+        return Duration.ofMinutes(minutes);
+    }
+}
@@ -0,0 +1,50 @@
+package home.backend.application;
+
+import home.backend.domain.GatewaySnapshot;
+import home.backend.domain.GatewaySnapshot.DeviceSnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+/** Looks up one measurement of one device in a snapshot and reads typed fields. */
+final class SnapshotFields {
+
+    private SnapshotFields() {
+    }
+
+    /** Twice the 300 s the UI treats as one polling cycle; older than that a reading is not live. */
+    private static final Duration MAX_AGE = Duration.ofSeconds(600);
+
+    static Optional<DeviceSnapshot> device(GatewaySnapshot snapshot, String name) {
+        return snapshot.devices().stream().filter(d -> d.name().equals(name)).findFirst();
+    }
+
+    /** A reading is stale when the device link is down, it is missing, or it is older than twice a cycle. */
+    static boolean stale(Optional<DeviceSnapshot> device, Optional<Measurement> reading, Instant now) {
+        return device.isEmpty() || !device.get().up() || reading.isEmpty()
+                || Duration.between(reading.get().time(), now).compareTo(MAX_AGE) > 0;
+    }
+
+    static Optional<Measurement> find(GatewaySnapshot snapshot, String device, String measurement) {
+        return snapshot.devices().stream()
+                .filter(d -> d.name().equals(device))
+                .map(DeviceSnapshot::measurements)
+                .flatMap(List::stream)
+                .filter(m -> m.measurement().equals(measurement))
+                .findFirst();
+    }
+
+    static Integer whole(Map<String, Double> fields, String name) {
+        Double value = fields.get(name);
+        return value == null ? null : (int) Math.round(value);
+    }
+
+    static boolean on(Map<String, Double> fields, String name) {
+        Double value = fields.get(name);
+        return value != null && value != 0;
+    }
+}
@@ -0,0 +1,10 @@
+package home.backend.domain;
+
+import java.time.Duration;
+
+/** Set a setpoint; with a duration the gateway restores the old value afterwards, else it stays. */
+public record Command(String setpoint, int value, Duration duration, String requestedBy) {
+
+    /** The gateway refuses longer boosts too; we refuse first, so the phone gets a clear 400. */
+    public static final int MAX_HOURS = 72;
+}
@@ -0,0 +1,10 @@
+package home.backend.domain;
+
+import java.time.Instant;
+
+/** The gateway's verdict on a command, passed on to the phone unchanged. */
+public record CommandResult(Status status, String message, Instant restoreAt) {
+
+    /** REJECTED: refused before any write. FAILED: the write or its read-back failed. */
+    public enum Status { APPLIED, REJECTED, FAILED }
+}
@@ -0,0 +1,21 @@
+package home.backend.domain;
+
+import java.time.Instant;
+import java.util.List;
+
+/**
+ * The house's electricity now (F7). Powers in W; grid + import / − export, battery + discharge /
+ * − charge. Values that come only from a stale source are null. {@code time} is the oldest source
+ * time (null when none was read); {@code sources} lists Deye and Fronius with their own time and freshness.
+ */
+public record EnergyView(Instant time, List<Source> sources, Double pvPowerW, Double gridPowerW,
+        Double batteryPowerW, Double batterySocPct, Double loadPowerW, Today today) {
+
+    /** One inverter; time is null and stale true when the gateway has no reading of it. */
+    public record Source(String name, Instant time, boolean stale) {
+    }
+
+    /** Day totals in kWh since local midnight; PV adds Deye and Fronius. */
+    public record Today(Double pvKwh, Double gridBoughtKwh, Double gridSoldKwh, Double loadKwh) {
+    }
+}
@@ -0,0 +1,17 @@
+package home.backend.domain;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+
+/** The gateway's latest state of every device, as the backend sees it. */
+public record GatewaySnapshot(List<DeviceSnapshot> devices) {
+
+    public record DeviceSnapshot(String name, boolean up, Instant lastSuccess, String lastError,
+            List<Measurement> measurements) {
+    }
+
+    /** One reading the gateway wrote to InfluxDB, e.g. heat_pump or deye. */
+    public record Measurement(String database, String measurement, Map<String, Double> fields, Instant time) {
+    }
+}
@@ -0,0 +1,11 @@
+package home.backend.domain;
+
+import java.time.Instant;
+import java.util.List;
+
+/** Health of the chain phone → backend → gateway → devices (F5). */
+public record HealthView(Instant time, boolean gatewayReachable, List<DeviceHealth> devices) {
+
+    public record DeviceHealth(String name, boolean up, Instant lastSuccess, String lastError) {
+    }
+}
@@ -0,0 +1,30 @@
+package home.backend.domain;
+
+import java.time.Instant;
+
+/**
+ * What the heat pump does now (F1). Without a reading from the gateway {@code time} and the values are
+ * null; {@code stale} is true when the device is down or the reading is older than 2 × 300 s.
+ */
+public record HeatPumpView(Instant time, boolean stale, State state, Integer compressorPercent, boolean heaterOn,
+        boolean alarm, Integer alarmCode, String alarmText, Pumps pumps, Temperatures temperatures,
+        Targets targets, Setpoints setpoints) {
+
+    /** From register 4227: 0 stop, 1 CO, 2 CWU, 3 both. */
+    public enum State { IDLE, HEATING_CO, HEATING_CWU, HEATING_BOTH }
+
+    public record Pumps(boolean co, boolean buffer, boolean circulation, boolean ground, boolean cwu) {
+    }
+
+    public record Temperatures(Double outdoor, Double indoor, Double coBuffer, Double cwu,
+            Double groundIn, Double groundOut, Double pumpOutlet, Double outdoorAvg) {
+    }
+
+    /** Targets the controller works to right now (economy or comfort period). */
+    public record Targets(Double room, Double co, Double cwu) {
+    }
+
+    /** The four setpoints F3 will change; whole °C. */
+    public record Setpoints(Integer coEconomy, Integer coComfort, Integer cwuEconomy, Integer cwuComfort) {
+    }
+}
@@ -0,0 +1,11 @@
+package home.backend.domain;
+
+import java.time.Instant;
+import java.util.List;
+
+/** One series over a time range, already averaged into chart-sized steps. */
+public record HistoryView(String series, String unit, List<Point> points) {
+
+    public record Point(Instant t, double v) {
+    }
+}
@@ -0,0 +1,29 @@
+package home.backend.domain;
+
+import java.util.List;
+
+/** A named one-tap bundle of setpoint changes (F3), e.g. boost or away. */
+public record Preset(String id, String name, List<Change> changes) {
+
+    /** {@code hours} null means "until changed back". */
+    public record Change(String setpoint, int value, Double hours) {
+
+        public Change {
+            if (setpoint == null || setpoint.isBlank()) {
+                throw new IllegalArgumentException("a preset change needs a setpoint");
+            }
+            if (hours != null && (hours <= 0 || hours > Command.MAX_HOURS)) {
+                throw new IllegalArgumentException("preset hours must be above 0 and at most " + Command.MAX_HOURS);
+            }
+        }
+    }
+
+    public Preset {
+        if (id == null || id.isBlank() || name == null || name.isBlank()) {
+            throw new IllegalArgumentException("a preset needs an id and a name");
+        }
+        if (changes == null || changes.isEmpty()) {
+            throw new IllegalArgumentException("preset " + id + " has no changes");
+        }
+    }
+}
@@ -0,0 +1,44 @@
+package home.backend.domain;
+
+import java.time.Instant;
+import java.util.List;
+
+/**
+ * What happened to each change of a preset, one entry per change in preset order. Changes run in
+ * order and stop at the first that is not applied; the rest are NOT_ATTEMPTED.
+ *
+ * <p>{@code status}: APPLIED when every change was; PARTIAL when some were and some were not;
+ * otherwise FAILED if any change failed or went unanswered (the pump may have changed), else
+ * REJECTED (nothing was written).
+ */
+public record PresetResult(Status status, List<ChangeResult> results) {
+
+    public enum Status { APPLIED, REJECTED, FAILED, PARTIAL }
+
+    /** UNKNOWN: the gateway did not answer, so the change may or may not have reached the pump. */
+    public enum ChangeStatus { APPLIED, REJECTED, FAILED, NOT_ATTEMPTED, UNKNOWN }
+
+    public record ChangeResult(ChangeStatus status, String message, Instant restoreAt) {
+
+        public static ChangeResult of(CommandResult verdict) {
+            return new ChangeResult(ChangeStatus.valueOf(verdict.status().name()), verdict.message(),
+                    verdict.restoreAt());
+        }
+
+        public static ChangeResult notAttempted() {
+            return new ChangeResult(ChangeStatus.NOT_ATTEMPTED, null, null);
+        }
+    }
+
+    public static PresetResult of(List<ChangeResult> results) {
+        boolean applied = results.stream().anyMatch(r -> r.status() == ChangeStatus.APPLIED);
+        boolean all = results.stream().allMatch(r -> r.status() == ChangeStatus.APPLIED);
+        boolean maybeWritten = results.stream()
+                .anyMatch(r -> r.status() == ChangeStatus.FAILED || r.status() == ChangeStatus.UNKNOWN);
+        Status status = all ? Status.APPLIED
+                : applied ? Status.PARTIAL
+                : maybeWritten ? Status.FAILED
+                : Status.REJECTED;
+        return new PresetResult(status, results);
+    }
+}
@@ -0,0 +1,7 @@
+package home.backend.domain;
+
+import java.time.Instant;
+
+/** A boost the gateway will undo at {@code due}, unless someone changed the register meanwhile. */
+public record Restore(String setpoint, int register, int originalValue, int appliedValue, Instant due) {
+}
@@ -0,0 +1,39 @@
+package home.backend.domain;
+
+import java.util.Arrays;
+import java.util.Optional;
+
+/** The history series the UI may ask for (F2); an allowlist, so no query is built from input. */
+public enum Series {
+    OUTDOOR_TEMP("outdoor_temp", "°C"),
+    INDOOR_TEMP("indoor_temp", "°C"),
+    CO_BUFFER_TEMP("co_buffer_temp", "°C"),
+    CWU_TEMP("cwu_temp", "°C"),
+    GROUND_IN_TEMP("ground_in_temp", "°C"),
+    GROUND_OUT_TEMP("ground_out_temp", "°C"),
+    PUMP_OUTLET_TEMP("pump_outlet_temp", "°C"),
+    GRID_POWER("grid_power", "W"),
+    PV_POWER("pv_power", "W"),
+    LOAD_POWER("load_power", "W"),
+    BATTERY_SOC("battery_soc", "%");
+
+    private final String id;
+    private final String unit;
+
+    Series(String id, String unit) {
+        this.id = id;
+        this.unit = unit;
+    }
+
+    public String id() {
+        return id;
+    }
+
+    public String unit() {
+        return unit;
+    }
+
+    public static Optional<Series> fromId(String id) {
+        return Arrays.stream(values()).filter(series -> series.id.equals(id)).findFirst();
+    }
+}
@@ -0,0 +1,9 @@
+package home.backend.domain;
+
+/** One of the four writable setpoints as the gateway reports it; {@code value} is null until it has been read. */
+public record Setpoint(String name, int register, int min, int max, int step, Integer value) {
+
+    public boolean allows(int candidate) {
+        return candidate >= min && candidate <= max && (candidate - min) % step == 0;
+    }
+}
@@ -0,0 +1,7 @@
+package home.backend.domain;
+
+import java.util.List;
+
+/** What the gateway knows about the setpoints: their limits, values and the pending restores. */
+public record SetpointState(List<Setpoint> setpoints, List<Restore> restores) {
+}
@@ -0,0 +1,7 @@
+package home.backend.domain;
+
+import java.util.List;
+
+/** The setpoints screen: gateway state plus the presets from the backend config. */
+public record SetpointsView(List<Setpoint> setpoints, List<Restore> restores, List<Preset> presets) {
+}
@@ -0,0 +1,15 @@
+[
+  {
+    "id": "cwu-now",
+    "name": "Ciepła woda teraz",
+    "changes": [ { "setpoint": "cwu_economy", "value": 45, "hours": 2 } ]
+  },
+  {
+    "id": "away",
+    "name": "Wyjazd",
+    "changes": [
+      { "setpoint": "cwu_comfort", "value": 10, "hours": null },
+      { "setpoint": "co_comfort", "value": 15, "hours": null }
+    ]
+  }
+]
@@ -0,0 +1,307 @@
+package home.backend;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpServer;
+import home.backend.adapters.http.ApiServer;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeSet;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/** The assembled backend against a stub gateway and a stub InfluxDB, both on localhost. */
+class BackendTest {
+
+    private static final ObjectMapper JSON = new ObjectMapper();
+
+    /** Just after the readings in the snapshot fixture, so they count as fresh. */
+    private static final Clock CLOCK = Clock.fixed(Instant.parse("2026-10-23T22:27:00Z"), ZoneOffset.UTC);
+
+    private final HttpClient client = HttpClient.newHttpClient();
+    private HttpServer gateway;
+    private HttpServer influx;
+    private ApiServer backend;
+
+    @BeforeEach
+    void start() throws IOException {
+        gateway = stub(Map.of(
+                "/health", "src/test/resources/gateway/health-all-up.json",
+                "/snapshot", "src/test/resources/gateway/snapshot-all-up.json"));
+        gateway.createContext("/commands", this::commands);
+        influx = stub(Map.of("/query", "src/test/resources/influx/influx-query-cwu-6h.json"));
+        var settings = new Settings(url(gateway), url(influx), 0, Duration.ofSeconds(2), Duration.ofSeconds(2),
+                "s3cret-token", null);
+        backend = Backend.assemble(settings, CLOCK);
+        backend.start();
+    }
+
+    private record Command(String authorization, String requestedBy, String body) {
+    }
+
+    private final List<Command> commandsSeen = new ArrayList<>();
+
+    /** The gateway's /commands, answering with the gateway's own contract examples. */
+    private void commands(HttpExchange exchange) throws IOException {
+        boolean post = exchange.getRequestMethod().equals("POST");
+        if (post) {
+            commandsSeen.add(new Command(exchange.getRequestHeaders().getFirst("Authorization"),
+                    exchange.getRequestHeaders().getFirst("X-Requested-By"),
+                    new String(exchange.getRequestBody().readAllBytes(), StandardCharsets.UTF_8)));
+        }
+        byte[] body = Files.readAllBytes(Path.of("../gateway/src/test/resources/commands/"
+                + (post ? "response-applied.json" : "setpoints.json")));
+        exchange.sendResponseHeaders(200, body.length);
+        exchange.getResponseBody().write(body);
+        exchange.close();
+    }
+
+    private HttpResponse<String> post(String path, String body) throws Exception {
+        var request = HttpRequest.newBuilder(URI.create("http://127.0.0.1:" + backend.port() + path))
+                .header("Remote-User", "anna").header("Content-Type", "application/json")
+                .header("X-Requested-With", "home-pump")
+                .POST(HttpRequest.BodyPublishers.ofString(body)).build();
+        return client.send(request, HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
+    }
+
+    @AfterEach
+    void stop() {
+        backend.stop();
+        gateway.stop(0);
+        influx.stop(0);
+    }
+
+    private static HttpServer stub(Map<String, String> bodies) throws IOException {
+        HttpServer server = HttpServer.create(new InetSocketAddress(InetAddress.getLoopbackAddress(), 0), 0);
+        bodies.forEach((path, file) -> server.createContext(path, exchange -> {
+            byte[] body = Files.readAllBytes(Path.of(file));
+            exchange.getResponseHeaders().set("Content-Type", "application/json");
+            exchange.sendResponseHeaders(200, body.length);
+            exchange.getResponseBody().write(body);
+            exchange.close();
+        }));
+        server.start();
+        return server;
+    }
+
+    private static URI url(HttpServer server) {
+        return URI.create("http://127.0.0.1:" + server.getAddress().getPort());
+    }
+
+    private HttpResponse<String> get(String path) throws Exception {
+        var request = HttpRequest.newBuilder(URI.create("http://127.0.0.1:" + backend.port() + path)).build();
+        return client.send(request, HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
+    }
+
+    /** The names of every field, nested ones as a.b; array elements are not descended into. */
+    private static TreeSet<String> fieldNames(JsonNode node, String prefix, TreeSet<String> names) {
+        node.fieldNames().forEachRemaining(name -> {
+            names.add(prefix + name);
+            fieldNames(node.get(name), prefix + name + ".", names);
+        });
+        return names;
+    }
+
+    private void assertServesApiShapeOf(String path, String example) throws Exception {
+        HttpResponse<String> response = get(path);
+
+        assertEquals(200, response.statusCode(), path);
+        assertEquals("application/json", response.headers().firstValue("Content-Type").orElseThrow());
+        JsonNode expected = JSON.readTree(Files.readString(Path.of("src/test/resources/api/" + example + ".json")));
+        assertEquals(fieldNames(expected, "", new TreeSet<>()),
+                fieldNames(JSON.readTree(response.body()), "", new TreeSet<>()), path);
+    }
+
+    /** The body equals the documented example, value by value. */
+    private void assertServesExactly(String path, String example) throws Exception {
+        HttpResponse<String> response = get(path);
+
+        assertEquals(200, response.statusCode(), path);
+        assertEquals(JSON.readTree(Files.readString(Path.of("src/test/resources/api/" + example + ".json"))),
+                JSON.readTree(response.body()), path);
+    }
+
+    @Test
+    void servesHeatPumpFromTheGatewayReadings() throws Exception {
+        assertServesExactly("/api/heat-pump", "heat-pump");
+    }
+
+    @Test
+    void servesEnergyFromTheGatewayReadings() throws Exception {
+        assertServesExactly("/api/energy", "energy");
+    }
+
+    @Test
+    void servesHealthOfEveryGatewayDevice() throws Exception {
+        assertServesApiShapeOf("/api/health", "health");
+        JsonNode health = JSON.readTree(get("/api/health").body());
+
+        assertTrue(health.get("gatewayReachable").asBoolean());
+        List<String> names = new ArrayList<>();
+        health.get("devices").forEach(device -> {
+            names.add(device.get("name").asText());
+            assertTrue(device.get("up").asBoolean(), names.getLast());
+        });
+        assertEquals(List.of("bme280", "deye", "fronius", "heat-pump", "house-meter"), names);
+    }
+
+    @Test
+    void servesHistoryFromInflux() throws Exception {
+        assertServesApiShapeOf("/api/history?series=cwu_temp&range=24h", "history");
+        JsonNode points = JSON.readTree(get("/api/history?series=cwu_temp&range=24h").body()).get("points");
+        assertFalse(points.isEmpty());
+    }
+
+    @Test
+    void servesSetpointsWithTheBuiltInPresets() throws Exception {
+        JsonNode view = JSON.readTree(get("/api/setpoints").body());
+
+        assertEquals(JSON.readTree(Files.readString(Path.of("src/test/resources/api/setpoints.json"))), view);
+    }
+
+    @Test
+    void boostGoesToTheGatewayWithTokenAndUser() throws Exception {
+        var response = post("/api/setpoints",
+                Files.readString(Path.of("src/test/resources/api/setpoints-request.json")));
+
+        assertEquals(200, response.statusCode());
+        assertEquals(JSON.readTree(Files.readString(Path.of("src/test/resources/api/setpoints-applied.json"))),
+                JSON.readTree(response.body()));
+        assertEquals(1, commandsSeen.size());
+        assertEquals("Bearer s3cret-token", commandsSeen.getFirst().authorization());
+        assertEquals("anna", commandsSeen.getFirst().requestedBy());
+        assertEquals(JSON.readTree(Files.readString(Path.of("../gateway/src/test/resources/commands/request-boost.json"))),
+                JSON.readTree(commandsSeen.getFirst().body()));
+    }
+
+    @Test
+    void presetsComeFromPresetsFile(@TempDir Path dir) throws Exception {
+        Path file = Files.writeString(dir.resolve("presets.json"),
+                "[{\"id\":\"bath\",\"name\":\"Kąpiel\",\"changes\":[{\"setpoint\":\"cwu_economy\",\"value\":48,\"hours\":1}]}]");
+        var custom = Backend.assemble(new Settings(url(gateway), url(influx), 0, Duration.ofSeconds(2),
+                Duration.ofSeconds(2), "s3cret-token", file), CLOCK);
+        custom.start();
+        try {
+            var request = HttpRequest.newBuilder(URI.create("http://127.0.0.1:" + custom.port() + "/api/presets/bath"))
+                    .header("Content-Type", "application/json").header("X-Requested-With", "home-pump")
+                    .POST(HttpRequest.BodyPublishers.noBody()).build();
+            var response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+            assertEquals(200, response.statusCode());
+            assertEquals("phone", commandsSeen.getFirst().requestedBy());
+            assertEquals(JSON.readTree("{\"setpoint\":\"cwu_economy\",\"value\":48,\"minutes\":60}"),
+                    JSON.readTree(commandsSeen.getFirst().body()));
+        } finally {
+            custom.stop();
+        }
+    }
+
+    @Test
+    void withoutTokenSetpointsAreUnavailableButLiveStateStays() throws Exception {
+        var noToken = Backend.assemble(new Settings(url(gateway), url(influx), 0, Duration.ofSeconds(2),
+                Duration.ofSeconds(2), null, null), CLOCK);
+        noToken.start();
+        try {
+            var base = "http://127.0.0.1:" + noToken.port();
+            assertEquals(503, client.send(HttpRequest.newBuilder(URI.create(base + "/api/setpoints")).build(),
+                    HttpResponse.BodyHandlers.ofString()).statusCode());
+            assertEquals(200, client.send(HttpRequest.newBuilder(URI.create(base + "/api/heat-pump")).build(),
+                    HttpResponse.BodyHandlers.ofString()).statusCode());
+            assertTrue(commandsSeen.isEmpty());
+        } finally {
+            noToken.stop();
+        }
+    }
+
+    @Test
+    void settingsNeedBothUrls() {
+        var e = assertThrows(IllegalArgumentException.class,
+                () -> Settings.fromEnvironment(Map.of("INFLUX_URL", "https://influx.example")));
+        assertTrue(e.getMessage().contains("GATEWAY_URL"));
+        e = assertThrows(IllegalArgumentException.class,
+                () -> Settings.fromEnvironment(Map.of("GATEWAY_URL", "http://gw:8080")));
+        assertTrue(e.getMessage().contains("INFLUX_URL"));
+    }
+
+    @Test
+    void urlsMayEndWithASingleSlash() {
+        var settings = Settings.fromEnvironment(
+                Map.of("GATEWAY_URL", "http://gw:8080/", "INFLUX_URL", "https://influx.example/"));
+
+        assertEquals(URI.create("http://gw:8080/"), settings.gatewayUrl());
+    }
+
+    @Test
+    void settingsHaveDefaults() {
+        var settings = Settings.fromEnvironment(
+                Map.of("GATEWAY_URL", "http://gw:8080", "INFLUX_URL", "https://influx.example"));
+
+        assertEquals(8080, settings.port());
+        assertEquals(Duration.ofSeconds(5), settings.gatewayTimeout());
+        assertEquals(Duration.ofSeconds(10), settings.influxTimeout());
+    }
+
+    @Test
+    void tokenAndPresetsFileAreOptional() {
+        var urls = Map.of("GATEWAY_URL", "http://gw:8080", "INFLUX_URL", "https://influx.example");
+        var none = Settings.fromEnvironment(urls);
+        var env = new HashMap<>(urls);
+        env.put("GATEWAY_TOKEN", " s3cret-token ");
+        env.put("PRESETS_FILE", "/etc/home-pump/presets.json");
+        var set = Settings.fromEnvironment(env);
+        env.put("GATEWAY_TOKEN", " ");
+        env.put("PRESETS_FILE", "");
+
+        assertEquals(null, none.gatewayToken());
+        assertEquals(null, none.presetsFile());
+        assertEquals("s3cret-token", set.gatewayToken());
+        assertEquals(Path.of("/etc/home-pump/presets.json"), set.presetsFile());
+        assertEquals(null, Settings.fromEnvironment(env).gatewayToken());
+    }
+
+    @Test
+    void settingsRejectBadValues() {
+        var urls = Map.of("GATEWAY_URL", "http://gw:8080", "INFLUX_URL", "https://influx.example");
+        for (Map<String, String> bad : List.of(
+                Map.of("GATEWAY_URL", "gw:8080", "INFLUX_URL", "https://influx.example"),
+                Map.of("GATEWAY_URL", "ftp://gw", "INFLUX_URL", "https://influx.example"),
+                Map.of("GATEWAY_URL", "http://gw:8080/api", "INFLUX_URL", "https://influx.example"),
+                Map.of("GATEWAY_URL", "http://gw:8080", "INFLUX_URL", "https://influx.example/influx/"),
+                Map.of("GATEWAY_URL", "http://gw:8080?x=1", "INFLUX_URL", "https://influx.example"))) {
+            assertThrows(IllegalArgumentException.class, () -> Settings.fromEnvironment(bad));
+        }
+        for (String name : List.of("PORT", "GATEWAY_TIMEOUT", "INFLUX_TIMEOUT")) {
+            for (String value : List.of("abc", "-1", "0x10", "99999999")) {
+                var env = new HashMap<>(urls);
+                env.put(name, value);
+                var e = assertThrows(IllegalArgumentException.class, () -> Settings.fromEnvironment(env), name + value);
+                assertTrue(e.getMessage().contains(name));
+            }
+        }
+    }
+}
@@ -0,0 +1,66 @@
+package home.backend.adapters.config;
+
+import home.backend.domain.Preset;
+import home.backend.domain.Preset.Change;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PresetFileTest {
+
+    @TempDir
+    Path dir;
+
+    private Path file(String json) throws IOException {
+        return Files.writeString(dir.resolve("presets.json"), json);
+    }
+
+    @Test
+    void defaultsAreBoostAndAway() {
+        var presets = PresetFile.load(null);
+
+        assertEquals(List.of(
+                new Preset("cwu-now", "Ciepła woda teraz", List.of(new Change("cwu_economy", 45, 2.0))),
+                new Preset("away", "Wyjazd", List.of(new Change("cwu_comfort", 10, null),
+                        new Change("co_comfort", 15, null)))), presets);
+    }
+
+    @Test
+    void fileReplacesTheDefaults() throws Exception {
+        var presets = PresetFile.load(file("""
+                [{"id": "bath", "name": "Kąpiel", "changes": [{"setpoint": "cwu_economy", "value": 48, "hours": 1.5}]}]
+                """));
+
+        assertEquals(List.of(new Preset("bath", "Kąpiel", List.of(new Change("cwu_economy", 48, 1.5)))), presets);
+    }
+
+    @Test
+    void unusableFilesAreRefusedWithTheirName() throws Exception {
+        for (String json : List.of(
+                "not json",
+                "{}",
+                "[{\"id\": \"a\", \"name\": \"A\", \"changes\": []}]",
+                "[{\"id\": \"\", \"name\": \"A\", \"changes\": [{\"setpoint\": \"co_comfort\", \"value\": 15}]}]",
+                "[{\"id\": \"a\", \"name\": \"A\", \"changes\": [{\"setpoint\": \"co_comfort\", \"value\": 15, \"hours\": 0}]}]",
+                "[{\"id\": \"a\", \"name\": \"A\", \"changes\": [{\"setpoint\": \"co_comfort\", \"value\": 15, \"hours\": 73}]}]",
+                "[{\"id\": \"a\", \"name\": \"A\", \"changes\": [{\"setpoint\": \"co_comfort\", \"value\": 15}]},"
+                        + "{\"id\": \"a\", \"name\": \"B\", \"changes\": [{\"setpoint\": \"co_comfort\", \"value\": 16}]}]")) {
+            Path file = file(json);
+            var e = assertThrows(IllegalArgumentException.class, () -> PresetFile.load(file), json);
+            assertTrue(e.getMessage().contains("PRESETS_FILE"), e.getMessage());
+        }
+    }
+
+    @Test
+    void missingFileIsRefused() {
+        assertThrows(IllegalArgumentException.class, () -> PresetFile.load(dir.resolve("absent.json")));
+    }
+}
@@ -0,0 +1,173 @@
+package home.backend.adapters.gateway;
+
+import com.sun.net.httpserver.HttpServer;
+import home.backend.domain.GatewaySnapshot.DeviceSnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.net.http.HttpTimeoutException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class GatewayHttpClientTest {
+
+    private HttpServer server;
+    private GatewayHttpClient client;
+
+    @BeforeEach
+    void startServer() throws IOException {
+        server = HttpServer.create(new InetSocketAddress("127.0.0.1", 0), 0);
+        server.start();
+        client = new GatewayHttpClient(URI.create("http://127.0.0.1:" + server.getAddress().getPort()),
+                Duration.ofMillis(500));
+    }
+
+    @AfterEach
+    void stopServer() {
+        server.stop(0);
+    }
+
+    private void serve(String path, int status, String body) {
+        server.createContext(path, exchange -> {
+            byte[] bytes = body.getBytes(StandardCharsets.UTF_8);
+            exchange.sendResponseHeaders(status, bytes.length);
+            exchange.getResponseBody().write(bytes);
+            exchange.close();
+        });
+    }
+
+    private void serveFiles(int healthStatus, String healthFile, String snapshotFile) throws IOException {
+        serve("/health", healthStatus, resource(healthFile));
+        serve("/snapshot", 200, resource(snapshotFile));
+    }
+
+    private static String resource(String name) throws IOException {
+        return Files.readString(Path.of("src/test/resources/gateway", name));
+    }
+
+    private static DeviceSnapshot device(List<DeviceSnapshot> devices, String name) {
+        return devices.stream().filter(d -> d.name().equals(name)).findFirst().orElseThrow();
+    }
+
+    @Test
+    void mapsEveryDeviceWithItsMeasurements() throws Exception {
+        serveFiles(200, "health-all-up.json", "snapshot-all-up.json");
+
+        var devices = client.snapshot().devices();
+
+        assertEquals(List.of("bme280", "deye", "fronius", "heat-pump", "house-meter"),
+                devices.stream().map(DeviceSnapshot::name).toList());
+        assertTrue(devices.stream().allMatch(DeviceSnapshot::up));
+        DeviceSnapshot pump = device(devices, "heat-pump");
+        assertEquals(Instant.parse("2026-10-23T22:26:00Z"), pump.lastSuccess());
+        assertNull(pump.lastError());
+        assertEquals(List.of("POMPA", "heat_pump"), pump.measurements().stream().map(Measurement::measurement).toList());
+        var measurement = pump.measurements().get(1);
+        assertEquals("Dom_Pompa", measurement.database());
+        assertEquals(4.3, measurement.fields().get("outdoor_temp"), 1e-9);
+        assertEquals(45.0, measurement.fields().get("setpoint_cwu_comfort"), 1e-9);
+        assertEquals(Instant.parse("2026-10-23T22:26:00Z"), measurement.time());
+        assertEquals(645.0, device(devices, "deye").measurements().get(0).fields().get("grid_power_w"));
+    }
+
+    @Test
+    void aDownDeviceAnswering503IsStillASnapshot() throws Exception {
+        serveFiles(503, "health-one-down.json", "snapshot-one-down.json");
+
+        var devices = client.snapshot().devices();
+
+        assertTrue(device(devices, "heat-pump").up());
+        DeviceSnapshot deye = device(devices, "deye");
+        assertFalse(deye.up());
+        assertEquals("Connect timed out", deye.lastError());
+        assertEquals(Instant.parse("2026-10-23T22:20:00Z"), deye.lastSuccess());
+        // The last good reading stays available, with its own time.
+        var last = deye.measurements().get(0);
+        assertEquals(570.0, last.fields().get("load_power_w"));
+        assertEquals(Instant.parse("2026-10-23T22:20:00Z"), last.time());
+    }
+
+    @Test
+    void aDeviceThatNeverSucceededHasNoLastSuccessAndNoMeasurements() throws Exception {
+        serveFiles(503, "health-never-succeeded.json", "snapshot-never-succeeded.json");
+
+        var devices = client.snapshot().devices();
+
+        var pump = device(devices, "heat-pump");
+        assertFalse(pump.up());
+        assertNull(pump.lastSuccess());
+        assertEquals("Connection refused", pump.lastError());
+        assertTrue(pump.measurements().isEmpty());
+        assertTrue(device(devices, "deye").up());
+    }
+
+    @Test
+    void ignoresPropertiesItDoesNotKnow() throws Exception {
+        serve("/health", 200, """
+                {"status":"UP","version":"2","devices":[{"name":"x","status":"UP","lastSuccess":null,"lastError":null,"extra":1}]}""");
+        serve("/snapshot", 200, """
+                [{"name":"x","new":true,"readings":[{"database":"d","measurement":"m","tags":{},
+                "fields":{"a":1.0},"time":"2026-10-24T10:00:00Z","unit":"C"}]}]""");
+
+        assertEquals(1, client.snapshot().devices().get(0).measurements().size());
+    }
+
+    @Test
+    void failsWhenSnapshotAnswers503() throws Exception {
+        serve("/health", 200, resource("health-all-up.json"));
+        serve("/snapshot", 503, "[]");
+
+        assertThrows(IOException.class, client::snapshot);
+    }
+
+    @Test
+    void failsOnServerError() {
+        serve("/health", 500, "{\"error\":\"boom\"}");
+
+        assertThrows(IOException.class, client::snapshot);
+    }
+
+    @Test
+    void failsOnBadJson() {
+        serve("/health", 200, "<html>not json</html>");
+
+        assertThrows(IOException.class, client::snapshot);
+    }
+
+    @Test
+    void failsWhenTheGatewayIsSlowerThanTheTimeout() {
+        server.createContext("/health", exchange -> {
+            try {
+                Thread.sleep(2000);
+            } catch (InterruptedException ignored) {
+                // the client gave up; nothing to answer
+            }
+            exchange.close();
+        });
+
+        assertThrows(HttpTimeoutException.class, client::snapshot);
+    }
+
+    @Test
+    void failsWhenTheGatewayIsUnreachable() {
+        server.stop(0);
+
+        assertThrows(IOException.class, client::snapshot);
+    }
+}
@@ -0,0 +1,186 @@
+package home.backend.adapters.gateway;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.sun.net.httpserver.HttpServer;
+import home.backend.domain.Command;
+import home.backend.domain.CommandResult.Status;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/** Against a stub gateway on localhost; the bodies are the gateway's own examples (the contract). */
+class GatewayHttpCommandsTest {
+
+    private static final ObjectMapper JSON = new ObjectMapper();
+    private static final Path CONTRACT = Path.of("../gateway/src/test/resources/commands");
+
+    private record Seen(String method, String authorization, String requestedBy, String body) {
+    }
+
+    private final List<Seen> seen = new ArrayList<>();
+    private HttpServer server;
+
+    @BeforeEach
+    void startServer() throws IOException {
+        server = HttpServer.create(new InetSocketAddress(InetAddress.getLoopbackAddress(), 0), 0);
+        answerCommands();
+        server.start();
+    }
+
+    @AfterEach
+    void stopServer() {
+        server.stop(0);
+    }
+
+    private int status;
+    private String body = "{}";
+
+    private void serve(int status, String body) {
+        this.status = status;
+        this.body = body;
+    }
+
+    private void answerCommands() {
+        server.createContext("/commands", exchange -> {
+            seen.add(new Seen(exchange.getRequestMethod(),
+                    exchange.getRequestHeaders().getFirst("Authorization"),
+                    exchange.getRequestHeaders().getFirst("X-Requested-By"),
+                    new String(exchange.getRequestBody().readAllBytes(), StandardCharsets.UTF_8)));
+            byte[] bytes = body.getBytes(StandardCharsets.UTF_8);
+            exchange.sendResponseHeaders(status, bytes.length);
+            exchange.getResponseBody().write(bytes);
+            exchange.close();
+        });
+    }
+
+    private GatewayHttpCommands commands(String token) {
+        return new GatewayHttpCommands(URI.create("http://127.0.0.1:" + server.getAddress().getPort()), token,
+                Duration.ofMillis(500));
+    }
+
+    private static String contract(String name) throws IOException {
+        return Files.readString(CONTRACT.resolve(name));
+    }
+
+    @Test
+    void sendsTheBoostWithTokenUserAndMinutes() throws Exception {
+        serve(200, contract("response-applied.json"));
+
+        var result = commands("s3cret-token").apply(new Command("cwu_economy", 45, Duration.ofHours(2), "anna"));
+
+        assertEquals(Status.APPLIED, result.status());
+        assertEquals(Instant.parse("2026-10-24T12:00:00Z"), result.restoreAt());
+        assertEquals(1, seen.size());
+        assertEquals("POST", seen.getFirst().method());
+        assertEquals("Bearer s3cret-token", seen.getFirst().authorization());
+        assertEquals("anna", seen.getFirst().requestedBy());
+        assertEquals(contractJson("request-boost.json"), contractJson(seen.getFirst().body()));
+    }
+
+    @Test
+    void awayHasNoMinutes() throws Exception {
+        serve(200, contract("response-applied.json"));
+
+        commands("s3cret-token").apply(new Command("cwu_comfort", 10, null, "phone"));
+
+        assertEquals(contractJson("request-away.json"), contractJson(seen.getFirst().body()));
+    }
+
+    @Test
+    void rejectionIsAVerdictNotAnError() throws Exception {
+        serve(422, contract("response-rejected.json"));
+
+        var result = commands("s3cret-token").apply(new Command("cwu_economy", 60, null, "phone"));
+
+        assertEquals(Status.REJECTED, result.status());
+        assertEquals("cwu_economy allows 5–48 in steps of 1, not 60", result.message());
+        assertNull(result.restoreAt());
+    }
+
+    @Test
+    void failedWriteIsAVerdict() throws Exception {
+        serve(502, "{\"status\":\"FAILED\",\"message\":\"read back 8, expected 45\",\"restoreAt\":null}");
+
+        assertEquals(Status.FAILED, commands("s3cret-token").apply(new Command("cwu_economy", 45, null, "phone")).status());
+    }
+
+    @Test
+    void readsSetpointsWithRestores() throws Exception {
+        serve(200, contract("setpoints.json"));
+
+        var state = commands("s3cret-token").setpoints();
+
+        assertEquals("GET", seen.getFirst().method());
+        assertEquals("Bearer s3cret-token", seen.getFirst().authorization());
+        assertEquals(4, state.setpoints().size());
+        assertEquals(48, state.setpoints().get(2).max());
+        assertEquals(1, state.restores().size());
+        assertEquals(8, state.restores().getFirst().originalValue());
+    }
+
+    @Test
+    void aSetpointNotReadYetStaysNullInsteadOfZero() throws Exception {
+        serve(200, "{\"setpoints\":[{\"name\":\"co_comfort\",\"register\":4132,\"min\":5,\"max\":25,\"step\":1,"
+                + "\"value\":null}],\"restores\":[]}");
+
+        assertNull(commands("s3cret-token").setpoints().setpoints().getFirst().value());
+    }
+
+    @Test
+    void otherStatusesAreNoVerdict() throws Exception {
+        for (int status : List.of(401, 404, 500, 503)) {
+            serve(status, "{\"error\":\"x\"}");
+            assertThrows(IOException.class, () -> commands("s3cret-token").setpoints(), "GET " + status);
+            assertThrows(IOException.class,
+                    () -> commands("s3cret-token").apply(new Command("cwu_economy", 45, null, "phone")), "POST " + status);
+        }
+    }
+
+    @Test
+    void unreadableAnswerIsNoVerdict() {
+        serve(200, "<html>proxy</html>");
+
+        assertThrows(IOException.class,
+                () -> commands("s3cret-token").apply(new Command("cwu_economy", 45, null, "phone")));
+    }
+
+    @Test
+    void withoutTokenNothingIsSent() {
+        serve(200, "{}");
+        var commands = commands(null);
+
+        assertThrows(IOException.class, () -> commands.setpoints());
+        assertThrows(IOException.class, () -> commands.apply(new Command("cwu_economy", 45, null, "phone")));
+        assertTrue(seen.isEmpty());
+    }
+
+    @Test
+    void unreachableGatewayIsAnIOException() {
+        server.stop(0);
+
+        assertThrows(IOException.class, () -> commands("s3cret-token").setpoints());
+    }
+
+    /** A contract file by name, or JSON text as is, parsed so that formatting does not matter. */
+    private static JsonNode contractJson(String nameOrJson) throws IOException {
+        return JSON.readTree(nameOrJson.endsWith(".json") ? contract(nameOrJson) : nameOrJson);
+    }
+}
@@ -0,0 +1,516 @@
+package home.backend.adapters.http;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import home.backend.application.EnergyService;
+import home.backend.adapters.config.PresetFile;
+import home.backend.application.GatewayClient;
+import home.backend.application.GatewayCommands;
+import home.backend.application.SetpointService;
+import home.backend.domain.Command;
+import home.backend.domain.CommandResult;
+import home.backend.domain.CommandResult.Status;
+import home.backend.domain.Restore;
+import home.backend.domain.Setpoint;
+import home.backend.domain.SetpointState;
+import home.backend.application.HealthService;
+import home.backend.application.HeatPumpService;
+import home.backend.application.HistoryRepository;
+import home.backend.application.HistoryService;
+import home.backend.domain.GatewaySnapshot;
+import home.backend.domain.GatewaySnapshot.DeviceSnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+import home.backend.domain.HistoryView.Point;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.Socket;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ApiServerTest {
+
+    private static final ObjectMapper JSON = new ObjectMapper();
+    private static final Instant HEALTH_TIME = Instant.parse("2026-10-23T22:14:00Z");
+
+    private final HttpClient client = HttpClient.newHttpClient();
+    private GatewaySnapshot snapshot;
+    private boolean gatewayDown;
+    private boolean historyDown;
+    private RuntimeException gatewayBug;
+    private final List<Command> sent = new ArrayList<>();
+    private Status verdict;
+    private boolean commandsDown;
+    private int answersBeforeDrop;
+    private ApiServer server;
+
+    @BeforeEach
+    void start() throws IOException {
+        snapshot = exampleSnapshot();
+        GatewayClient gateway = () -> {
+            if (gatewayDown) {
+                throw new IOException("tunnel down");
+            }
+            if (gatewayBug != null) {
+                throw gatewayBug;
+            }
+            return snapshot;
+        };
+        HistoryRepository history = (series, from, to, max) -> {
+            if (historyDown) {
+                throw new IOException("influx down");
+            }
+            return List.of(new Point(Instant.parse("2026-10-23T10:00:00Z"), 14.1),
+                    new Point(Instant.parse("2026-10-23T11:00:00Z"), 38.5),
+                    new Point(Instant.parse("2026-10-23T12:00:00Z"), 44.2));
+        };
+        verdict = Status.APPLIED;
+        answersBeforeDrop = Integer.MAX_VALUE;
+        GatewayCommands commands = new GatewayCommands() {
+            @Override
+            public CommandResult apply(Command command) throws IOException {
+                if (commandsDown || sent.size() >= answersBeforeDrop) {
+                    throw new IOException("tunnel down");
+                }
+                sent.add(command);
+                return switch (verdict) {
+                    case APPLIED -> new CommandResult(verdict, "cwu_economy 8 → 45, restore at 2026-10-24T12:00:00Z",
+                            command.duration() == null ? null : Instant.parse("2026-10-24T12:00:00Z"));
+                    case REJECTED -> new CommandResult(verdict, "cwu_economy allows 5–48 in steps of 1, not 60", null);
+                    case FAILED -> new CommandResult(verdict, "read back 8, expected 45", null);
+                };
+            }
+
+            @Override
+            public SetpointState setpoints() throws IOException {
+                if (commandsDown) {
+                    throw new IOException("tunnel down");
+                }
+                return new SetpointState(List.of(new Setpoint("co_economy", 4131, 5, 25, 1, 18),
+                        new Setpoint("co_comfort", 4132, 5, 25, 1, 19),
+                        new Setpoint("cwu_economy", 4143, 5, 48, 1, 8),
+                        new Setpoint("cwu_comfort", 4144, 5, 48, 1, 45)),
+                        List.of(new Restore("cwu_economy", 4143, 8, 45, Instant.parse("2026-10-24T12:00:00Z"))));
+            }
+        };
+        Clock clock = Clock.fixed(HEALTH_TIME, ZoneOffset.UTC);
+        server = new ApiServer(0, new HeatPumpService(gateway, clock), new EnergyService(gateway, clock),
+                new HealthService(gateway, clock), new HistoryService(history, clock),
+                new SetpointService(commands, PresetFile.load(null)));
+        server.start();
+    }
+
+    @AfterEach
+    void stop() {
+        server.stop();
+    }
+
+    private static GatewaySnapshot exampleSnapshot() {
+        Map<String, Double> pump = new HashMap<>(Map.of("outdoor_temp", 4.3, "indoor_temp", 21.2,
+                "co_buffer_temp", 16.9, "cwu_temp", 13.6, "ground_in_temp", 16.0, "ground_out_temp", 14.3,
+                "pump_outlet_temp", 19.7, "outdoor_avg_temp", 4.8, "target_room_temp", 18.0));
+        pump.putAll(Map.of("target_co_temp", 31.0, "target_cwu_temp", 8.0, "pump_mode", 0.0,
+                "output_compressor", 0.0, "output_heater", 0.0, "alarm", 0.0,
+                "setpoint_co_economy", 18.0, "setpoint_co_comfort", 19.0, "setpoint_cwu_economy", 8.0));
+        pump.putAll(Map.of("setpoint_cwu_comfort", 45.0, "output_co", 0.0, "output_buffer", 0.0,
+                "output_circulation", 0.0, "output_ground", 0.0, "output_cwu", 0.0));
+        Instant pumpTime = Instant.parse("2026-10-23T22:13:35Z");
+        Instant energyTime = Instant.parse("2026-10-23T22:26:00Z");
+        Map<String, Double> deye = Map.of("pv1_power_w", 0.0, "pv2_power_w", 0.0, "pv_today_kwh", 29.9,
+                "grid_power_w", 645.0, "battery_power_w", -24.0, "battery_soc_pct", 99.0,
+                "load_power_w", 570.0, "grid_bought_today_kwh", 16.8, "grid_sold_today_kwh", 22.3,
+                "load_today_kwh", 24.2);
+        return new GatewaySnapshot(List.of(
+                new DeviceSnapshot("heat-pump", true, pumpTime, null,
+                        List.of(new Measurement("Dom_Pompa", "heat_pump", pump, energyTime))),
+                new DeviceSnapshot("deye", true, energyTime, null,
+                        List.of(new Measurement("home", "deye", deye, energyTime))),
+                new DeviceSnapshot("fronius", true, energyTime, null,
+                        List.of(new Measurement("home", "fronius",
+                                Map.of("pv_power_w", 0.0, "energy_day_wh", 4400.0), energyTime)))));
+    }
+
+    private HttpResponse<String> get(String path) throws Exception {
+        HttpRequest request = HttpRequest.newBuilder(URI.create("http://localhost:" + server.port() + path))
+                .build();
+        return client.send(request, HttpResponse.BodyHandlers.ofString());
+    }
+
+    private static JsonNode example(String name) throws IOException {
+        try (InputStream in = ApiServerTest.class.getResourceAsStream("/api/" + name + ".json")) {
+            return JSON.readTree(in);
+        }
+    }
+
+    private void assertMatchesExample(String path, String example) throws Exception {
+        HttpResponse<String> response = get(path);
+
+        assertEquals(200, response.statusCode());
+        assertEquals("application/json", response.headers().firstValue("Content-Type").orElseThrow());
+        assertEquals("no-store", response.headers().firstValue("Cache-Control").orElseThrow());
+        assertEquals(example(example), JSON.readTree(response.body()));
+    }
+
+    @Test
+    void heatPumpMatchesExample() throws Exception {
+        assertMatchesExample("/api/heat-pump", "heat-pump");
+    }
+
+    @Test
+    void energyMatchesExample() throws Exception {
+        assertMatchesExample("/api/energy", "energy");
+    }
+
+    @Test
+    void healthMatchesExample() throws Exception {
+        snapshot = new GatewaySnapshot(List.of(snapshot.devices().get(0),
+                new DeviceSnapshot("deye", false, null, "connect timed out", List.of())));
+        assertMatchesExample("/api/health", "health");
+    }
+
+    @Test
+    void heatPumpWithoutReadingMatchesUnreadExample() throws Exception {
+        snapshot = new GatewaySnapshot(List.of());
+        assertMatchesExample("/api/heat-pump", "heat-pump-unread");
+    }
+
+    @Test
+    void staleDeyeMatchesExample() throws Exception {
+        Instant old = Instant.parse("2026-10-23T21:00:00Z");
+        List<DeviceSnapshot> devices = new ArrayList<>(snapshot.devices());
+        Measurement deye = devices.get(1).measurements().get(0);
+        devices.set(1, new DeviceSnapshot("deye", true, old, null,
+                List.of(new Measurement("home", "deye", deye.fields(), old))));
+        snapshot = new GatewaySnapshot(devices);
+        assertMatchesExample("/api/energy", "energy-deye-stale");
+    }
+
+    @Test
+    void historyMatchesExample() throws Exception {
+        assertMatchesExample("/api/history?series=cwu_temp&range=24h", "history");
+    }
+
+    @Test
+    void historyRangeDefaultsTo24Hours() throws Exception {
+        assertEquals(200, get("/api/history?series=cwu_temp").statusCode());
+    }
+
+    @Test
+    void unreachableGatewayIs503WithJsonError() throws Exception {
+        gatewayDown = true;
+
+        for (String path : List.of("/api/heat-pump", "/api/energy")) {
+            HttpResponse<String> response = get(path);
+            assertEquals(503, response.statusCode());
+            assertEquals("gateway unreachable", JSON.readTree(response.body()).get("error").asText());
+        }
+    }
+
+    @Test
+    void healthStaysOkWhenGatewayIsUnreachable() throws Exception {
+        gatewayDown = true;
+
+        HttpResponse<String> response = get("/api/health");
+
+        assertEquals(200, response.statusCode());
+        assertEquals(false, JSON.readTree(response.body()).get("gatewayReachable").asBoolean());
+    }
+
+    @Test
+    void unknownSeriesOrRangeIs400() throws Exception {
+        assertEquals(400, get("/api/history?series=nope").statusCode());
+        assertEquals(400, get("/api/history").statusCode());
+        assertEquals(400, get("/api/history?series=cwu_temp&range=30d").statusCode());
+    }
+
+    @Test
+    void malformedQueryIs400NotADroppedConnection() throws Exception {
+        for (String path : List.of("/api/history?series=%", "/api/history?series=%zz&range=24h")) {
+            assertEquals(400, rawGet(path), path);
+        }
+    }
+
+    @Test
+    void unusableGatewayPayloadIs502() throws Exception {
+        for (RuntimeException bug : List.of(new IllegalStateException("Duplicate key deye"),
+                new NullPointerException("status"))) {
+            gatewayBug = bug;
+            for (String path : List.of("/api/heat-pump", "/api/energy", "/api/health")) {
+                HttpResponse<String> response = get(path);
+                assertEquals(502, response.statusCode(), path);
+                assertEquals("bad gateway response", JSON.readTree(response.body()).get("error").asText());
+            }
+        }
+    }
+
+    @Test
+    void influxFailureIs502() throws Exception {
+        historyDown = true;
+
+        assertEquals(502, get("/api/history?series=cwu_temp&range=7d").statusCode());
+    }
+
+    private static final String[] BROWSER_HEADERS = {"Content-Type", "application/json", "X-Requested-With", "home-pump"};
+
+    /** A POST as the web UI sends it; extra headers come after the defaults. */
+    private HttpResponse<String> post(String path, String body, String... headers) throws Exception {
+        var all = new ArrayList<>(List.of(BROWSER_HEADERS));
+        all.addAll(List.of(headers));
+        return rawPost(path, body, all.toArray(String[]::new));
+    }
+
+    private HttpResponse<String> rawPost(String path, String body, String... headers) throws Exception {
+        HttpRequest.Builder request = HttpRequest.newBuilder(URI.create("http://localhost:" + server.port() + path))
+                .POST(HttpRequest.BodyPublishers.ofString(body));
+        if (headers.length > 0) {
+            request.headers(headers);
+        }
+        return client.send(request.build(), HttpResponse.BodyHandlers.ofString());
+    }
+
+    private static final String BOOST = "{\"setpoint\":\"cwu_economy\",\"value\":45,\"hours\":2}";
+
+    @Test
+    void setpointsMatchExample() throws Exception {
+        assertMatchesExample("/api/setpoints", "setpoints");
+    }
+
+    @Test
+    void appliedBoostMatchesExampleAndRestoresAfterTwoHours() throws Exception {
+        HttpResponse<String> response = post("/api/setpoints", BOOST);
+
+        assertEquals(200, response.statusCode());
+        assertEquals(example("setpoints-applied"), JSON.readTree(response.body()));
+        assertEquals(List.of(new Command("cwu_economy", 45, java.time.Duration.ofHours(2), "phone")), sent);
+    }
+
+    @Test
+    void rejectedIs422AndMatchesExample() throws Exception {
+        verdict = Status.REJECTED;
+
+        HttpResponse<String> response = post("/api/setpoints", BOOST);
+
+        assertEquals(422, response.statusCode());
+        assertEquals(example("setpoints-rejected"), JSON.readTree(response.body()));
+    }
+
+    @Test
+    void failedWriteIs502() throws Exception {
+        verdict = Status.FAILED;
+
+        assertEquals(502, post("/api/setpoints", BOOST).statusCode());
+    }
+
+    @Test
+    void forwardedUserIsPassedOnAndOddNamesFallBack() throws Exception {
+        post("/api/setpoints", BOOST, "Remote-User", "anna.k@example.pl");
+        post("/api/setpoints", BOOST, "Remote-User", "anna smith");
+        post("/api/setpoints", BOOST);
+
+        assertEquals(List.of("anna.k@example.pl", "phone", "phone"), sent.stream().map(Command::requestedBy).toList());
+    }
+
+    @Test
+    void badSetpointRequestsAre400AndSendNothing() throws Exception {
+        for (String body : List.of("", "not json", "[]", "{}", "{\"setpoint\":\"cwu_economy\"}",
+                "{\"setpoint\":\"cwu_economy\",\"value\":45.5}",
+                "{\"setpoint\":\"cwu_economy\",\"value\":\"45\"}",
+                "{\"setpoint\":\"cwu_economy\",\"value\":45,\"hours\":0}",
+                "{\"setpoint\":\"cwu_economy\",\"value\":45,\"hours\":-1}",
+                "{\"setpoint\":\"cwu_economy\",\"value\":45,\"hours\":72.5}",
+                "{\"setpoint\":\"cwu_economy\",\"value\":45,\"minutes\":5}")) {
+            assertEquals(400, post("/api/setpoints", body).statusCode(), body);
+        }
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void presetResultsMatchExample() throws Exception {
+        HttpResponse<String> response = post("/api/presets/away", "");
+
+        assertEquals(200, response.statusCode());
+        JsonNode body = JSON.readTree(response.body());
+        assertEquals(example("setpoints-preset-applied").get("results").size(), body.get("results").size());
+        assertEquals("APPLIED", body.get("status").asText());
+        assertEquals(List.of("cwu_comfort", "co_comfort"), sent.stream().map(Command::setpoint).toList());
+    }
+
+    @Test
+    void presetCutShortByALostLinkKeepsTheResultsSoFar() throws Exception {
+        answersBeforeDrop = 1;
+
+        HttpResponse<String> response = post("/api/presets/away", "{}");
+
+        assertEquals(502, response.statusCode());
+        assertEquals(example("setpoints-preset-partial"), JSON.readTree(response.body()));
+    }
+
+    @Test
+    void unknownPresetIs404() throws Exception {
+        assertEquals(404, post("/api/presets/nope", "").statusCode());
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void presetOutsideLimitsIs422() throws Exception {
+        verdict = Status.REJECTED;
+
+        assertEquals(422, post("/api/presets/away", "").statusCode());
+    }
+
+    @Test
+    void unreachableGatewayOnSetpointsIs503() throws Exception {
+        commandsDown = true;
+
+        assertEquals(503, get("/api/setpoints").statusCode());
+        assertEquals(503, post("/api/setpoints", BOOST).statusCode());
+        assertEquals(503, post("/api/presets/away", "").statusCode());
+    }
+
+    @Test
+    void writesWithoutJsonContentTypeAre415() throws Exception {
+        for (String path : List.of("/api/setpoints", "/api/presets/away")) {
+            assertEquals(415, rawPost(path, BOOST, "X-Requested-With", "home-pump").statusCode(), path);
+            assertEquals(415, rawPost(path, BOOST, "X-Requested-With", "home-pump", "Content-Type", "text/plain")
+                    .statusCode(), path);
+        }
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void jsonContentTypeMayCarryACharset() throws Exception {
+        assertEquals(200, rawPost("/api/setpoints", BOOST, "X-Requested-With", "home-pump",
+                "Content-Type", "application/json; charset=utf-8").statusCode());
+    }
+
+    @Test
+    void writesWithoutTheCustomHeaderAre403() throws Exception {
+        for (String path : List.of("/api/setpoints", "/api/presets/away")) {
+            assertEquals(403, rawPost(path, BOOST, "Content-Type", "application/json").statusCode(), path);
+            assertEquals(403, rawPost(path, BOOST, "Content-Type", "application/json",
+                    "X-Requested-With", "XMLHttpRequest").statusCode(), path);
+        }
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void writesFromAnotherOriginAre403() throws Exception {
+        for (String path : List.of("/api/setpoints", "/api/presets/away")) {
+            for (String origin : List.of("https://evil.example", "null", "http://localhost:1")) {
+                assertEquals(403, post(path, BOOST, "Origin", origin).statusCode(), origin);
+            }
+        }
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void writesFromTheSameOriginAreAccepted() throws Exception {
+        assertEquals(200, post("/api/setpoints", BOOST, "Origin", "http://localhost:" + server.port()).statusCode());
+    }
+
+    @Test
+    void setpointMethodsAreChecked() throws Exception {
+        assertEquals(405, post("/api/history", "").statusCode());
+        assertEquals(405, get("/api/presets/away").statusCode());
+        HttpRequest put = HttpRequest.newBuilder(URI.create("http://localhost:" + server.port() + "/api/setpoints"))
+                .PUT(HttpRequest.BodyPublishers.noBody()).build();
+        assertEquals(405, client.send(put, HttpResponse.BodyHandlers.ofString()).statusCode());
+    }
+
+    @Test
+    void apiAcceptsOnlyGet() throws Exception {
+        HttpRequest post = HttpRequest.newBuilder(URI.create("http://localhost:" + server.port() + "/api/health"))
+                .POST(HttpRequest.BodyPublishers.noBody()).build();
+
+        assertEquals(405, client.send(post, HttpResponse.BodyHandlers.ofString()).statusCode());
+    }
+
+    @Test
+    void everyResponseCarriesTheSecurityHeaders() throws Exception {
+        var paths = List.of("/", "/index.html", "/missing.css", "/api/health", "/api/nothing", "/api/history");
+        for (String path : paths) {
+            assertSecurityHeaders(get(path), path);
+        }
+        assertSecurityHeaders(post("/api/health", ""), "405");
+        assertSecurityHeaders(post("/api/setpoints", "{"), "400");
+        assertSecurityHeaders(rawPost("/api/setpoints", BOOST), "403");
+    }
+
+    private static void assertSecurityHeaders(HttpResponse<String> response, String what) {
+        var headers = response.headers();
+        assertEquals("default-src 'none'; script-src 'self'; style-src 'self'; img-src 'self' data:; "
+                + "font-src 'self'; connect-src 'self'; base-uri 'none'; form-action 'self'; frame-ancestors 'none'",
+                headers.firstValue("Content-Security-Policy").orElse(null), what);
+        assertEquals("nosniff", headers.firstValue("X-Content-Type-Options").orElse(null), what);
+        assertEquals("no-referrer", headers.firstValue("Referrer-Policy").orElse(null), what);
+    }
+
+    @Test
+    void unknownApiPathIs404() throws Exception {
+        assertEquals(404, get("/api/nothing").statusCode());
+    }
+
+    @Test
+    void apiRoutesMatchTheExactPathOnly() throws Exception {
+        for (String path : List.of("/api/heat-pumpX", "/api/heat-pump/", "/api/heat-pump/x", "/api/energy2",
+                "/api/healthz", "/api/history2?series=cwu_temp", "/api/setpointsX")) {
+            assertEquals(404, get(path).statusCode(), path);
+        }
+        assertEquals(404, post("/api/setpointsX", BOOST).statusCode());
+        assertEquals(200, get("/api/heat-pump?x=1").statusCode());
+    }
+
+    @Test
+    void stopClosesThePort() {
+        server.stop();
+
+        assertThrows(IOException.class, () -> get("/api/health"));
+    }
+
+    @Test
+    void requestBodiesOver4KbAre413AndSendNothing() throws Exception {
+        String padding = " ".repeat(4096 - BOOST.length());
+        assertEquals(200, post("/api/setpoints", BOOST + padding).statusCode());
+        sent.clear();
+
+        assertEquals(413, post("/api/setpoints", BOOST + padding + " ").statusCode());
+        assertEquals(413, post("/api/presets/away", "x".repeat(5000)).statusCode());
+        assertEquals(0, sent.size());
+    }
+
+    @Test
+    void answersOnlyTheApi() throws Exception {
+        // The web UI is the frontend container's (ADR-010); the backend serves no files.
+        for (String path : List.of("/", "/index.html", "/assets/index.js", "/api", "/api/")) {
+            assertEquals(404, get(path).statusCode(), path);
+        }
+    }
+
+    /** The JDK client normalises dot segments, so send the request line as is. */
+    private int rawGet(String path) throws IOException {
+        try (Socket socket = new Socket("localhost", server.port())) {
+            socket.getOutputStream().write(("GET " + path + " HTTP/1.1\r\nHost: localhost\r\n"
+                    + "Connection: close\r\n\r\n").getBytes(StandardCharsets.US_ASCII));
+            String statusLine = new String(socket.getInputStream().readAllBytes(), StandardCharsets.US_ASCII)
+                    .lines().findFirst().orElseThrow();
+            return Integer.parseInt(statusLine.split(" ")[1]);
+        }
+    }
+}
@@ -0,0 +1,244 @@
+package home.backend.adapters.influx;
+
+import com.sun.net.httpserver.HttpServer;
+import home.backend.domain.HistoryView.Point;
+import home.backend.domain.Series;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class InfluxHistoryRepositoryTest {
+
+    private static final Instant FROM = Instant.parse("2026-10-24T00:00:00Z");
+    private static final Instant TO = Instant.parse("2026-10-24T06:00:00Z");
+    private static final Duration TIMEOUT = Duration.ofSeconds(5);
+
+    private HttpServer server;
+    private final List<Map<String, String>> requests = Collections.synchronizedList(new ArrayList<>());
+    private volatile CountDownLatch rendezvous = new CountDownLatch(0);
+    private final AtomicInteger metTogether = new AtomicInteger();
+    private final Map<String, String> bodyByField = new HashMap<>();
+    private int status = 200;
+    private String failingField = "";
+    private String defaultBody = "{\"results\":[{\"statement_id\":0}]}";
+
+    @BeforeEach
+    void startServer() throws IOException {
+        server = HttpServer.create(new InetSocketAddress(InetAddress.getLoopbackAddress(), 0), 0);
+        // Concurrent handlers: the repository asks for the parts of a series at the same time.
+        server.setExecutor(Executors.newCachedThreadPool());
+        server.createContext("/query", exchange -> {
+            Map<String, String> params = params(exchange.getRequestURI().getRawQuery());
+            requests.add(params);
+            rendezvous.countDown();
+            try {
+                if (rendezvous.await(5, TimeUnit.SECONDS)) {
+                    metTogether.incrementAndGet();
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+            String body = bodyByField.entrySet().stream()
+                    .filter(e -> params.get("q").contains("\"" + e.getKey() + "\""))
+                    .map(Map.Entry::getValue).findFirst().orElse(defaultBody);
+            byte[] bytes = body.getBytes(StandardCharsets.UTF_8);
+            boolean fails = !failingField.isEmpty() && params.get("q").contains("\"" + failingField + "\"");
+            exchange.sendResponseHeaders(fails ? 500 : status, bytes.length);
+            exchange.getResponseBody().write(bytes);
+            exchange.close();
+        });
+        server.start();
+    }
+
+    @AfterEach
+    void stopServer() {
+        server.stop(0);
+    }
+
+    @Test
+    void asksTheLegacyDatabaseForATemperatureWithQuotedFieldName() throws IOException {
+        defaultBody = fixture("influx-query-cwu-6h.json");
+
+        List<Point> points = repository(TIMEOUT).history(Series.CWU_TEMP, FROM, TO, 360);
+
+        assertEquals(1, requests.size());
+        assertEquals("Dom_Pompa", requests.get(0).get("db"));
+        assertEquals("ms", requests.get(0).get("epoch"));
+        assertEquals("SELECT mean(\"Temp cwu\") FROM \"POMPA\" WHERE time >= 1792800000000ms"
+                + " AND time < 1792821600000ms GROUP BY time(1m) fill(none)", requests.get(0).get("q"));
+        assertEquals(7, points.size());
+        assertEquals(new Point(Instant.ofEpochMilli(1792771200000L), 43.76666666666667), points.get(0));
+    }
+
+    @Test
+    void asksTheElectricityDatabaseForGridPower() throws IOException {
+        repository(TIMEOUT).history(Series.GRID_POWER, FROM, TO, 72);
+
+        assertEquals("electricity", requests.get(0).get("db"));
+        assertEquals("SELECT mean(\"total_power_active\") FROM \"PRAD2\" WHERE time >= 1792800000000ms"
+                + " AND time < 1792821600000ms GROUP BY time(5m) fill(none)", requests.get(0).get("q"));
+    }
+
+    @Test
+    void roundsTheStepUpToWholeMinutes() throws IOException {
+        repository(TIMEOUT).history(Series.LOAD_POWER, FROM, TO, 100);
+
+        assertTrue(requests.get(0).get("q").contains("GROUP BY time(4m)"), requests.get(0).get("q"));
+    }
+
+    @Test
+    void sumsPvPowerAcrossMeasurementsAndKeepsBucketsWithOnePart() throws IOException {
+        bodyByField.put("pv1_power_w", series(1000, 100.0, 2000, 200.0));
+        bodyByField.put("pv2_power_w", series(1000, 50.0));
+        bodyByField.put("pv_power_w", series(2000, 5.0, 3000, 7.0));
+
+        List<Point> points = repository(TIMEOUT).history(Series.PV_POWER, FROM, TO, 72);
+
+        assertEquals(3, requests.size());
+        assertEquals(List.of(
+                new Point(Instant.ofEpochMilli(1000), 150.0),
+                new Point(Instant.ofEpochMilli(2000), 205.0),
+                new Point(Instant.ofEpochMilli(3000), 7.0)), points);
+    }
+
+    @Test
+    void asksForTheThreePvPartsAtTheSameTime() throws IOException {
+        rendezvous = new CountDownLatch(3);
+
+        repository(TIMEOUT).history(Series.PV_POWER, FROM, TO, 72);
+
+        // A handler passes the latch only when all three requests are in flight together.
+        assertEquals(3, metTogether.get());
+    }
+
+    @Test
+    void oneFailingPartFailsTheWholeSeries() {
+        failingField = "pv2_power_w";
+
+        assertThrows(IOException.class, () -> repository(TIMEOUT).history(Series.PV_POWER, FROM, TO, 72));
+    }
+
+    @Test
+    void sortsPointsByTime() throws IOException {
+        defaultBody = series(3000, 3.0, 1000, 1.0, 2000, 2.0);
+
+        List<Point> points = repository(TIMEOUT).history(Series.BATTERY_SOC, FROM, TO, 72);
+
+        assertEquals(List.of(1000L, 2000L, 3000L), points.stream().map(p -> p.t().toEpochMilli()).toList());
+    }
+
+    @Test
+    void noDataGivesAnEmptyList() throws IOException {
+        defaultBody = fixture("influx-query-empty.json");
+
+        assertEquals(List.of(), repository(TIMEOUT).history(Series.PV_POWER, FROM, TO, 72));
+    }
+
+    @Test
+    void topLevelErrorIsAnIOException() throws IOException {
+        defaultBody = fixture("influx-query-error.json");
+
+        IOException e = assertThrows(IOException.class,
+                () -> repository(TIMEOUT).history(Series.CWU_TEMP, FROM, TO, 72));
+        assertTrue(e.getMessage().contains("error parsing query"), e.getMessage());
+    }
+
+    @Test
+    void perResultErrorIsAnIOException() {
+        defaultBody = "{\"results\":[{\"statement_id\":0,\"error\":\"database not found: electricity\"}]}";
+
+        IOException e = assertThrows(IOException.class,
+                () -> repository(TIMEOUT).history(Series.GRID_POWER, FROM, TO, 72));
+        assertTrue(e.getMessage().contains("database not found"), e.getMessage());
+    }
+
+    @Test
+    void httpErrorIsAnIOException() {
+        status = 503;
+
+        IOException e = assertThrows(IOException.class,
+                () -> repository(TIMEOUT).history(Series.CWU_TEMP, FROM, TO, 72));
+        assertTrue(e.getMessage().contains("503"), e.getMessage());
+    }
+
+    @Test
+    void badJsonIsAnIOException() {
+        defaultBody = "<html>not json";
+
+        assertThrows(IOException.class, () -> repository(TIMEOUT).history(Series.CWU_TEMP, FROM, TO, 72));
+    }
+
+    @Test
+    void slowServerTimesOut() {
+        server.removeContext("/query");
+        server.createContext("/query", exchange -> {
+            try {
+                Thread.sleep(1000);
+            } catch (InterruptedException ignored) {
+                Thread.currentThread().interrupt();
+            }
+            exchange.close();
+        });
+
+        assertThrows(IOException.class,
+                () -> repository(Duration.ofMillis(200)).history(Series.CWU_TEMP, FROM, TO, 72));
+    }
+
+    @Test
+    void rejectsAnEmptyRange() {
+        assertThrows(IllegalArgumentException.class,
+                () -> repository(TIMEOUT).history(Series.CWU_TEMP, FROM, FROM, 72));
+    }
+
+    private InfluxHistoryRepository repository(Duration timeout) {
+        URI base = URI.create("http://127.0.0.1:" + server.getAddress().getPort());
+        return new InfluxHistoryRepository(new InfluxSettings(base, timeout));
+    }
+
+    private static String series(Object... timeAndValue) {
+        StringBuilder rows = new StringBuilder();
+        for (int i = 0; i < timeAndValue.length; i += 2) {
+            rows.append(i == 0 ? "" : ",").append('[').append(timeAndValue[i]).append(',')
+                    .append(timeAndValue[i + 1]).append(']');
+        }
+        return "{\"results\":[{\"statement_id\":0,\"series\":[{\"name\":\"m\",\"columns\":[\"time\",\"mean\"],"
+                + "\"values\":[" + rows + "]}]}]}";
+    }
+
+    private static String fixture(String name) throws IOException {
+        return Files.readString(Path.of("src/test/resources/influx", name));
+    }
+
+    private static Map<String, String> params(String rawQuery) {
+        Map<String, String> params = new HashMap<>();
+        for (String pair : rawQuery.split("&")) {
+            String[] kv = pair.split("=", 2);
+            params.put(kv[0], URLDecoder.decode(kv[1], StandardCharsets.UTF_8));
+        }
+        return params;
+    }
+}
@@ -0,0 +1,349 @@
+package home.backend.application;
+
+import home.backend.domain.EnergyView;
+import home.backend.domain.EnergyView.Source;
+import home.backend.domain.GatewaySnapshot;
+import home.backend.domain.GatewaySnapshot.DeviceSnapshot;
+import home.backend.domain.GatewaySnapshot.Measurement;
+import home.backend.domain.HealthView;
+import home.backend.domain.HeatPumpView;
+import home.backend.domain.HeatPumpView.State;
+import home.backend.domain.HistoryView;
+import home.backend.domain.HistoryView.Point;
+import home.backend.domain.Series;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ServicesTest {
+
+    private static final Instant NOW = Instant.parse("2026-10-24T12:00:00Z");
+    private static final Instant READ = Instant.parse("2026-10-24T11:59:50Z");
+    private static final Clock CLOCK = Clock.fixed(NOW, ZoneOffset.UTC);
+
+    private static DeviceSnapshot device(String name, String database, String measurement,
+            Map<String, Double> fields) {
+        return new DeviceSnapshot(name, true, READ, null,
+                List.of(new Measurement(database, measurement, fields, READ)));
+    }
+
+    private static GatewayClient gateway(DeviceSnapshot... devices) {
+        return () -> new GatewaySnapshot(List.of(devices));
+    }
+
+    private static GatewayClient unreachable() {
+        return () -> {
+            throw new IOException("tunnel down");
+        };
+    }
+
+    private static HeatPumpView heatPump(Map<String, Double> fields) throws IOException {
+        return new HeatPumpService(gateway(device("heat-pump", "Dom_Pompa", "heat_pump", fields)), CLOCK)
+                .current();
+    }
+
+    @Test
+    void heatPumpStateComesFromPumpMode() throws IOException {
+        assertEquals(State.IDLE, heatPump(Map.of("pump_mode", 0.0)).state());
+        assertEquals(State.HEATING_CO, heatPump(Map.of("pump_mode", 1.0)).state());
+        assertEquals(State.HEATING_CWU, heatPump(Map.of("pump_mode", 2.0)).state());
+        assertEquals(State.HEATING_BOTH, heatPump(Map.of("pump_mode", 3.0)).state());
+    }
+
+    @Test
+    void heatPumpMapsOutputsAlarmAndTime() throws IOException {
+        HeatPumpView view = heatPump(Map.of("output_compressor", 66.0, "output_heater", 100.0,
+                "output_cwu", 100.0, "output_co", 0.0, "alarm", 4.0, "setpoint_cwu_economy", 8.0));
+
+        assertEquals(READ, view.time());
+        assertEquals(66, view.compressorPercent());
+        assertTrue(view.heaterOn());
+        assertTrue(view.alarm());
+        assertTrue(view.pumps().cwu());
+        assertFalse(view.pumps().co());
+        assertEquals(8, view.setpoints().cwuEconomy());
+    }
+
+    @Test
+    void heatPumpAlarmCodeRaisesTheAlarmAndIsNamedInPolish() throws IOException {
+        HeatPumpView sensor = heatPump(Map.of("alarm", 0.0, "alarm_code", 3.0));
+        HeatPumpView pressure = heatPump(Map.of("alarm_code", 1003.0));
+        HeatPumpView unknown = heatPump(Map.of("alarm_code", 77.0));
+        HeatPumpView healthy = heatPump(Map.of("alarm", 0.0, "alarm_code", 0.0));
+
+        assertTrue(sensor.alarm());
+        assertEquals(3, sensor.alarmCode());
+        assertEquals("Usterka czujnika temperatury CO", sensor.alarmText());
+        assertEquals("Zadziałał presostat (ciśnienie)", pressure.alarmText());
+        assertEquals("Kod usterki 77", unknown.alarmText());
+        assertFalse(healthy.alarm());
+        assertNull(healthy.alarmText());
+    }
+
+    @Test
+    void heatPumpMissingFieldsAreNull() throws IOException {
+        HeatPumpView view = heatPump(Map.of());
+
+        assertNull(view.state());
+        assertNull(view.compressorPercent());
+        assertNull(view.temperatures().outdoor());
+        assertNull(view.targets().cwu());
+        assertNull(view.setpoints().coComfort());
+        assertFalse(view.alarm());
+        assertNull(view.alarmCode());
+        assertNull(view.alarmText());
+    }
+
+    @Test
+    void heatPumpTemperaturesDropBinaryNoiseOfTheGatewayScaling() throws IOException {
+        HeatPumpView view = heatPump(Map.of("indoor_temp", 212 * 0.1, "target_co_temp", 310 * 0.1,
+                "outdoor_temp", -43 * 0.1));
+
+        assertEquals(21.2, view.temperatures().indoor());
+        assertEquals(31.0, view.targets().co());
+        assertEquals(-4.3, view.temperatures().outdoor());
+    }
+
+    @Test
+    void heatPumpIgnoresMeasurementFromAnotherDatabase() throws IOException {
+        HeatPumpService service = new HeatPumpService(gateway(
+                device("heat-pump", "other", "heat_pump", Map.of("pump_mode", 1.0))), CLOCK);
+
+        HeatPumpView view = service.current();
+
+        assertNull(view.state());
+        assertNull(view.time());
+        assertTrue(view.stale());
+    }
+
+    @Test
+    void heatPumpWithoutAReadingHasNoTimeAndIsStale() throws IOException {
+        HeatPumpView view = new HeatPumpService(gateway(), CLOCK).current();
+
+        assertNull(view.time());
+        assertTrue(view.stale());
+        assertNull(view.state());
+        assertNull(view.temperatures().outdoor());
+        assertNull(view.setpoints().cwuComfort());
+    }
+
+    @Test
+    void heatPumpPumpModeOutOfRangeHasNoState() throws IOException {
+        assertNull(heatPump(Map.of("pump_mode", 4.0)).state());
+        assertNull(heatPump(Map.of("pump_mode", -1.0)).state());
+    }
+
+    @Test
+    void heatPumpIsFreshOnlyWhileUpAndNotOlderThanTenMinutes() throws IOException {
+        assertFalse(heatPump(Map.of("pump_mode", 0.0)).stale());
+        assertTrue(heatPumpRead(true, NOW.minusSeconds(601)).stale());
+        assertFalse(heatPumpRead(true, NOW.minusSeconds(600)).stale());
+        HeatPumpView down = heatPumpRead(false, READ);
+        assertTrue(down.stale());
+        assertEquals(READ, down.time());
+    }
+
+    private static HeatPumpView heatPumpRead(boolean up, Instant time) throws IOException {
+        var reading = new Measurement("Dom_Pompa", "heat_pump", Map.of("pump_mode", 0.0), time);
+        return new HeatPumpService(gateway(new DeviceSnapshot("heat-pump", up, time, null, List.of(reading))),
+                CLOCK).current();
+    }
+
+    @Test
+    void heatPumpPropagatesGatewayFailure() {
+        assertThrows(IOException.class, () -> new HeatPumpService(unreachable(), CLOCK).current());
+    }
+
+    private static EnergyView energy(DeviceSnapshot... devices) throws IOException {
+        return new EnergyService(gateway(devices), CLOCK).current();
+    }
+
+    private static final Map<String, Double> DEYE = Map.of("pv1_power_w", 1000.0, "pv2_power_w", 500.0,
+            "pv_today_kwh", 10.0, "grid_power_w", -200.0, "battery_soc_pct", 80.0, "load_power_w", 900.0);
+    private static final Map<String, Double> FRONIUS = Map.of("pv_power_w", 2000.0, "energy_day_wh", 4400.0);
+
+    @Test
+    void energySumsPvOfBothInverters() throws IOException {
+        EnergyView view = energy(device("deye", "home", "deye", DEYE),
+                device("fronius", "home", "fronius", FRONIUS));
+
+        assertEquals(3500.0, view.pvPowerW());
+        assertEquals(14.4, view.today().pvKwh());
+        assertEquals(-200.0, view.gridPowerW());
+        assertEquals(80.0, view.batterySocPct());
+        assertNull(view.batteryPowerW());
+    }
+
+    @Test
+    void energyWithoutFroniusUsesDeyeOnly() throws IOException {
+        EnergyView view = energy(device("deye", "home", "deye", DEYE));
+
+        assertEquals(1500.0, view.pvPowerW());
+        assertEquals(10.0, view.today().pvKwh());
+        assertEquals(READ, view.time());
+    }
+
+    @Test
+    void energyWithoutDeyeKeepsFroniusPvAndNullsTheRest() throws IOException {
+        EnergyView view = energy(device("fronius", "home", "fronius", FRONIUS));
+
+        assertEquals(2000.0, view.pvPowerW());
+        assertEquals(4.4, view.today().pvKwh());
+        assertNull(view.gridPowerW());
+        assertNull(view.today().loadKwh());
+    }
+
+    @Test
+    void energyWithoutSourcesHasNoTimeAndBothSourcesStale() throws IOException {
+        EnergyView view = energy();
+
+        assertNull(view.pvPowerW());
+        assertNull(view.today().pvKwh());
+        assertNull(view.time());
+        assertEquals(List.of(new Source("deye", null, true), new Source("fronius", null, true)), view.sources());
+    }
+
+    private static DeviceSnapshot deyeRead(boolean up, Instant time) {
+        return new DeviceSnapshot("deye", up, time, null, List.of(new Measurement("home", "deye", DEYE, time)));
+    }
+
+    @Test
+    void energyWithStaleDeyeKeepsOnlyFreshFroniusAndTheOldestTime() throws IOException {
+        Instant old = NOW.minusSeconds(3600);
+
+        EnergyView view = energy(deyeRead(true, old), device("fronius", "home", "fronius", FRONIUS));
+
+        assertEquals(old, view.time());
+        assertEquals(List.of(new Source("deye", old, true), new Source("fronius", READ, false)), view.sources());
+        assertEquals(2000.0, view.pvPowerW());
+        assertEquals(4.4, view.today().pvKwh());
+        assertNull(view.gridPowerW());
+        assertNull(view.batteryPowerW());
+        assertNull(view.batterySocPct());
+        assertNull(view.loadPowerW());
+        assertNull(view.today().loadKwh());
+    }
+
+    @Test
+    void energyWithStaleFroniusKeepsDeyeAlone() throws IOException {
+        Instant old = NOW.minusSeconds(3600);
+        var fronius = new DeviceSnapshot("fronius", true, old, null,
+                List.of(new Measurement("home", "fronius", FRONIUS, old)));
+
+        EnergyView view = energy(device("deye", "home", "deye", DEYE), fronius);
+
+        assertEquals(1500.0, view.pvPowerW());
+        assertEquals(10.0, view.today().pvKwh());
+        assertEquals(80.0, view.batterySocPct());
+        assertEquals(old, view.time());
+    }
+
+    @Test
+    void energySourceWhoseLinkIsDownIsStaleEvenWithAFreshReading() throws IOException {
+        EnergyView view = energy(deyeRead(false, READ));
+
+        assertTrue(view.sources().get(0).stale());
+        assertNull(view.gridPowerW());
+        assertEquals(READ, view.time());
+    }
+
+    @Test
+    void energyPropagatesGatewayFailure() {
+        assertThrows(IOException.class, () -> new EnergyService(unreachable(), CLOCK).current());
+    }
+
+    @Test
+    void healthListsDevices() {
+        DeviceSnapshot down = new DeviceSnapshot("deye", false, null, "connect timed out", List.of());
+
+        HealthView view = new HealthService(gateway(device("heat-pump", "Dom_Pompa", "heat_pump", Map.of()),
+                down), CLOCK).current();
+
+        assertTrue(view.gatewayReachable());
+        assertEquals(NOW, view.time());
+        assertEquals(2, view.devices().size());
+        assertEquals("connect timed out", view.devices().get(1).lastError());
+        assertFalse(view.devices().get(1).up());
+        assertEquals(READ, view.devices().get(0).lastSuccess());
+    }
+
+    @Test
+    void healthWithUnreachableGatewayHasNoDevices() {
+        HealthView view = new HealthService(unreachable(), CLOCK).current();
+
+        assertFalse(view.gatewayReachable());
+        assertTrue(view.devices().isEmpty());
+    }
+
+    /** Remembers the request and answers with one point. */
+    private static final class RecordingHistory implements HistoryRepository {
+        Series series;
+        Instant from;
+        Instant to;
+        int maxPoints;
+
+        @Override
+        public List<Point> history(Series series, Instant from, Instant to, int maxPoints) {
+            this.series = series;
+            this.from = from;
+            this.to = to;
+            this.maxPoints = maxPoints;
+            return List.of(new Point(from, 1.5));
+        }
+    }
+
+    @Test
+    void historyDefaultsToLast24Hours() throws IOException {
+        RecordingHistory repository = new RecordingHistory();
+
+        HistoryView view = new HistoryService(repository, CLOCK).history("cwu_temp", null);
+
+        assertEquals("cwu_temp", view.series());
+        assertEquals("°C", view.unit());
+        assertEquals(1, view.points().size());
+        assertEquals(Series.CWU_TEMP, repository.series);
+        assertEquals(NOW, repository.to);
+        assertEquals(NOW.minus(Duration.ofHours(24)), repository.from);
+        assertEquals(300, repository.maxPoints);
+    }
+
+    @Test
+    void historyOfSevenDays() throws IOException {
+        RecordingHistory repository = new RecordingHistory();
+
+        new HistoryService(repository, CLOCK).history("pv_power", "7d");
+
+        assertEquals(NOW.minus(Duration.ofDays(7)), repository.from);
+    }
+
+    @Test
+    void historyRejectsUnknownSeriesAndRange() {
+        HistoryService service = new HistoryService(new RecordingHistory(), CLOCK);
+
+        assertThrows(IllegalArgumentException.class, () -> service.history("nope", "24h"));
+        assertThrows(IllegalArgumentException.class, () -> service.history(null, "24h"));
+        assertThrows(IllegalArgumentException.class, () -> service.history("cwu_temp", "30d"));
+        assertThrows(IllegalArgumentException.class, () -> service.history("cwu_temp", ""));
+    }
+
+    @Test
+    void historyPropagatesRepositoryFailure() {
+        HistoryService service = new HistoryService((series, from, to, max) -> {
+            throw new IOException("influx down");
+        }, CLOCK);
+
+        assertThrows(IOException.class, () -> service.history("cwu_temp", "24h"));
+    }
+}
@@ -0,0 +1,204 @@
+package home.backend.application;
+
+import home.backend.adapters.config.PresetFile;
+import home.backend.domain.Command;
+import home.backend.domain.CommandResult;
+import home.backend.domain.CommandResult.Status;
+import home.backend.domain.Preset;
+import home.backend.domain.Preset.Change;
+import home.backend.domain.PresetResult;
+import home.backend.domain.PresetResult.ChangeResult;
+import home.backend.domain.PresetResult.ChangeStatus;
+import home.backend.domain.Restore;
+import home.backend.domain.Setpoint;
+import home.backend.domain.SetpointState;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class SetpointServiceTest {
+
+    private static final SetpointState STATE = new SetpointState(List.of(
+            new Setpoint("co_comfort", 4132, 5, 25, 1, 19),
+            new Setpoint("cwu_economy", 4143, 5, 48, 1, 8),
+            new Setpoint("cwu_comfort", 4144, 5, 48, 1, 45)), List.<Restore>of());
+
+    private final List<Command> sent = new ArrayList<>();
+    /** What the gateway does on the next calls to apply, in order: a Status, or an IOException; then APPLIED. */
+    private final List<Object> script = new ArrayList<>();
+    private boolean down;
+    private final GatewayCommands gateway = new GatewayCommands() {
+        @Override
+        public CommandResult apply(Command command) throws IOException {
+            if (down) {
+                throw new IOException("tunnel down");
+            }
+            Object next = script.isEmpty() ? Status.APPLIED : script.removeFirst();
+            if (next instanceof IOException e) {
+                throw e;
+            }
+            sent.add(command);
+            return new CommandResult((Status) next, command.setpoint(), null);
+        }
+
+        @Override
+        public SetpointState setpoints() throws IOException {
+            if (down) {
+                throw new IOException("tunnel down");
+            }
+            return STATE;
+        }
+    };
+    private final List<Preset> presets = PresetFile.load(null);
+    private final SetpointService service = new SetpointService(gateway, presets);
+
+    @Test
+    void viewJoinsGatewayStateAndPresets() throws Exception {
+        var view = service.current();
+
+        assertEquals(STATE.setpoints(), view.setpoints());
+        assertEquals(presets, view.presets());
+    }
+
+    @Test
+    void hoursBecomeAWholeNumberOfMinutes() throws Exception {
+        service.apply("cwu_economy", 45, 1.5, "anna");
+        service.apply("cwu_comfort", 10, null, "anna");
+
+        assertEquals(new Command("cwu_economy", 45, Duration.ofMinutes(90), "anna"), sent.get(0));
+        assertEquals(new Command("cwu_comfort", 10, null, "anna"), sent.get(1));
+    }
+
+    @Test
+    void durationUnderAMinuteIsRefusedBeforeSending() {
+        assertThrows(IllegalArgumentException.class, () -> service.apply("cwu_economy", 45, 0.001, "anna"));
+        assertThrows(IllegalArgumentException.class, () -> service.apply("cwu_economy", 45, -1.0, "anna"));
+        assertThrows(IllegalArgumentException.class, () -> service.apply("cwu_economy", 45, 72.5, "anna"));
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void seventyTwoHoursIsTheLongestBoost() throws Exception {
+        service.apply("cwu_economy", 45, 72.0, "anna");
+
+        assertEquals(Duration.ofHours(72), sent.getFirst().duration());
+    }
+
+    @Test
+    void boostPresetSendsOneTimedCommand() throws Exception {
+        var result = service.applyPreset("cwu-now", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.APPLIED, result.status());
+        assertEquals(List.of(new Command("cwu_economy", 45, Duration.ofHours(2), "anna")), sent);
+    }
+
+    @Test
+    void awayPresetSendsBothChangesUntilChanged() throws Exception {
+        var result = service.applyPreset("away", "anna").orElseThrow();
+
+        assertEquals(2, result.results().size());
+        assertEquals(List.of(new Command("cwu_comfort", 10, null, "anna"), new Command("co_comfort", 15, null, "anna")),
+                sent);
+    }
+
+    @Test
+    void unknownPresetIsEmpty() throws Exception {
+        assertTrue(service.applyPreset("nope", "anna").isEmpty());
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void presetOutsideGatewayLimitsWritesNothing() throws Exception {
+        var tooHot = new Preset("hot", "Za gorąco", List.of(new Change("co_comfort", 15, null),
+                new Change("cwu_economy", 60, 2.0)));
+
+        var result = new SetpointService(gateway, List.of(tooHot)).applyPreset("hot", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.REJECTED, result.status());
+        assertEquals(List.of(ChangeStatus.NOT_ATTEMPTED, ChangeStatus.REJECTED), statuses(result));
+        assertTrue(result.results().getLast().message().contains("cwu_economy"));
+        assertTrue(sent.isEmpty());
+    }
+
+    @Test
+    void presetWithUnknownSetpointWritesNothing() throws Exception {
+        var odd = new Preset("odd", "Dziwny", List.of(new Change("garage_heater", 1, null)));
+
+        var result = new SetpointService(gateway, List.of(odd)).applyPreset("odd", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.REJECTED, result.status());
+        assertTrue(sent.isEmpty());
+    }
+
+    private static List<ChangeStatus> statuses(PresetResult result) {
+        return result.results().stream().map(ChangeResult::status).toList();
+    }
+
+    @Test
+    void presetReportsEveryChangeAndStopsAfterTheFirstThatIsNotApplied() throws Exception {
+        script.add(Status.FAILED);
+
+        var result = service.applyPreset("away", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.FAILED, result.status());
+        assertEquals(List.of(ChangeStatus.FAILED, ChangeStatus.NOT_ATTEMPTED), statuses(result));
+        assertEquals(1, sent.size());
+    }
+
+    @Test
+    void secondChangeRejectedLeavesThePresetPartial() throws Exception {
+        script.addAll(List.of(Status.APPLIED, Status.REJECTED));
+
+        var result = service.applyPreset("away", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.PARTIAL, result.status());
+        assertEquals(List.of(ChangeStatus.APPLIED, ChangeStatus.REJECTED), statuses(result));
+    }
+
+    @Test
+    void firstChangeRejectedByTheGatewayIsRejectedAsAWhole() throws Exception {
+        script.add(Status.REJECTED);
+
+        var result = service.applyPreset("away", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.REJECTED, result.status());
+        assertEquals(List.of(ChangeStatus.REJECTED, ChangeStatus.NOT_ATTEMPTED), statuses(result));
+    }
+
+    @Test
+    void lostAnswerOnTheSecondChangeKeepsTheFirstResult() throws Exception {
+        script.addAll(List.of(Status.APPLIED, new IOException("tunnel dropped")));
+
+        var result = service.applyPreset("away", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.PARTIAL, result.status());
+        assertEquals(List.of(ChangeStatus.APPLIED, ChangeStatus.UNKNOWN), statuses(result));
+    }
+
+    @Test
+    void lostAnswerOnTheFirstChangeIsFailedNotUnreachable() throws Exception {
+        script.add(new IOException("tunnel dropped"));
+
+        var result = service.applyPreset("away", "anna").orElseThrow();
+
+        assertEquals(PresetResult.Status.FAILED, result.status());
+        assertEquals(List.of(ChangeStatus.UNKNOWN, ChangeStatus.NOT_ATTEMPTED), statuses(result));
+    }
+
+    @Test
+    void unreachableGatewayIsAnIOException() {
+        down = true;
+
+        assertThrows(IOException.class, service::current);
+        assertThrows(IOException.class, () -> service.apply("cwu_economy", 45, null, "anna"));
+        assertThrows(IOException.class, () -> service.applyPreset("away", "anna"));
+        assertTrue(sent.isEmpty());
+    }
+}
@@ -0,0 +1,20 @@
+package home.backend.domain;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class SeriesTest {
+
+    @Test
+    void findsSeriesByItsId() {
+        assertEquals(Optional.of(Series.CWU_TEMP), Series.fromId("cwu_temp"));
+    }
+
+    @Test
+    void unknownIdFindsNothing() {
+        assertEquals(Optional.empty(), Series.fromId("DROP MEASUREMENT"));
+    }
+}
@@ -0,0 +1,13 @@
+{
+  "time": "2026-10-23T21:00:00Z",
+  "sources": [
+    { "name": "deye", "time": "2026-10-23T21:00:00Z", "stale": true },
+    { "name": "fronius", "time": "2026-10-23T22:26:00Z", "stale": false }
+  ],
+  "pvPowerW": 0.0,
+  "gridPowerW": null,
+  "batteryPowerW": null,
+  "batterySocPct": null,
+  "loadPowerW": null,
+  "today": { "pvKwh": 4.4, "gridBoughtKwh": null, "gridSoldKwh": null, "loadKwh": null }
+}
@@ -0,0 +1,13 @@
+{
+  "time": "2026-10-23T22:26:00Z",
+  "sources": [
+    { "name": "deye", "time": "2026-10-23T22:26:00Z", "stale": false },
+    { "name": "fronius", "time": "2026-10-23T22:26:00Z", "stale": false }
+  ],
+  "pvPowerW": 0.0,
+  "gridPowerW": 645.0,
+  "batteryPowerW": -24.0,
+  "batterySocPct": 99.0,
+  "loadPowerW": 570.0,
+  "today": { "pvKwh": 34.3, "gridBoughtKwh": 16.8, "gridSoldKwh": 22.3, "loadKwh": 24.2 }
+}
@@ -0,0 +1,8 @@
+{
+  "time": "2026-10-23T22:14:00Z",
+  "gatewayReachable": true,
+  "devices": [
+    { "name": "heat-pump", "up": true, "lastSuccess": "2026-10-23T22:13:35Z", "lastError": null },
+    { "name": "deye", "up": false, "lastSuccess": null, "lastError": "connect timed out" }
+  ]
+}
@@ -0,0 +1,17 @@
+{
+  "time": null,
+  "stale": true,
+  "state": null,
+  "compressorPercent": null,
+  "heaterOn": false,
+  "alarm": false,
+  "alarmCode": null,
+  "alarmText": null,
+  "pumps": { "co": false, "buffer": false, "circulation": false, "ground": false, "cwu": false },
+  "temperatures": {
+    "outdoor": null, "indoor": null, "coBuffer": null, "cwu": null,
+    "groundIn": null, "groundOut": null, "pumpOutlet": null, "outdoorAvg": null
+  },
+  "targets": { "room": null, "co": null, "cwu": null },
+  "setpoints": { "coEconomy": null, "coComfort": null, "cwuEconomy": null, "cwuComfort": null }
+}
@@ -0,0 +1,17 @@
+{
+  "time": "2026-10-23T22:26:00Z",
+  "stale": false,
+  "state": "IDLE",
+  "compressorPercent": 0,
+  "heaterOn": false,
+  "alarm": false,
+  "alarmCode": null,
+  "alarmText": null,
+  "pumps": { "co": false, "buffer": false, "circulation": false, "ground": false, "cwu": false },
+  "temperatures": {
+    "outdoor": 4.3, "indoor": 21.2, "coBuffer": 16.9, "cwu": 13.6,
+    "groundIn": 16.0, "groundOut": 14.3, "pumpOutlet": 19.7, "outdoorAvg": 4.8
+  },
+  "targets": { "room": 18.0, "co": 31.0, "cwu": 8.0 },
+  "setpoints": { "coEconomy": 18, "coComfort": 19, "cwuEconomy": 8, "cwuComfort": 45 }
+}
@@ -0,0 +1,9 @@
+{
+  "series": "cwu_temp",
+  "unit": "°C",
+  "points": [
+    { "t": "2026-10-23T10:00:00Z", "v": 14.1 },
+    { "t": "2026-10-23T11:00:00Z", "v": 38.5 },
+    { "t": "2026-10-23T12:00:00Z", "v": 44.2 }
+  ]
+}
@@ -0,0 +1 @@
+{ "status": "APPLIED", "message": "cwu_economy 8 → 45, restore at 2026-10-24T12:00:00Z", "restoreAt": "2026-10-24T12:00:00Z" }
@@ -0,0 +1,7 @@
+{
+  "status": "APPLIED",
+  "results": [
+    { "status": "APPLIED", "message": "cwu_comfort 45 → 10", "restoreAt": null },
+    { "status": "APPLIED", "message": "co_comfort 19 → 15", "restoreAt": null }
+  ]
+}
@@ -0,0 +1,7 @@
+{
+  "status": "PARTIAL",
+  "results": [
+    { "status": "APPLIED", "message": "cwu_economy 8 → 45, restore at 2026-10-24T12:00:00Z", "restoreAt": null },
+    { "status": "UNKNOWN", "message": "no answer from the gateway", "restoreAt": null }
+  ]
+}
@@ -0,0 +1 @@
+{ "status": "REJECTED", "message": "cwu_economy allows 5–48 in steps of 1, not 60", "restoreAt": null }
@@ -0,0 +1 @@
+{ "setpoint": "cwu_economy", "value": 45, "hours": 2 }
@@ -0,0 +1,26 @@
+{
+  "setpoints": [
+    { "name": "co_economy", "register": 4131, "min": 5, "max": 25, "step": 1, "value": 18 },
+    { "name": "co_comfort", "register": 4132, "min": 5, "max": 25, "step": 1, "value": 19 },
+    { "name": "cwu_economy", "register": 4143, "min": 5, "max": 48, "step": 1, "value": 8 },
+    { "name": "cwu_comfort", "register": 4144, "min": 5, "max": 48, "step": 1, "value": 45 }
+  ],
+  "restores": [
+    { "setpoint": "cwu_economy", "register": 4143, "originalValue": 8, "appliedValue": 45, "due": "2026-10-24T12:00:00Z" }
+  ],
+  "presets": [
+    {
+      "id": "cwu-now",
+      "name": "Ciepła woda teraz",
+      "changes": [ { "setpoint": "cwu_economy", "value": 45, "hours": 2.0 } ]
+    },
+    {
+      "id": "away",
+      "name": "Wyjazd",
+      "changes": [
+        { "setpoint": "cwu_comfort", "value": 10, "hours": null },
+        { "setpoint": "co_comfort", "value": 15, "hours": null }
+      ]
+    }
+  ]
+}
@@ -0,0 +1 @@
+{"status":"UP","devices":[{"name":"bme280","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"deye","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"fronius","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"heat-pump","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"house-meter","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null}]}
@@ -0,0 +1 @@
+{"status":"DOWN","devices":[{"name":"bme280","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"deye","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"fronius","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"heat-pump","status":"DOWN","lastSuccess":null,"lastError":"Connection refused"},{"name":"house-meter","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null}]}
@@ -0,0 +1 @@
+{"status":"DOWN","devices":[{"name":"bme280","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"deye","status":"DOWN","lastSuccess":"2026-10-23T22:20:00Z","lastError":"Connect timed out"},{"name":"fronius","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"heat-pump","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"house-meter","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null}]}
@@ -0,0 +1 @@
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truncated
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+{"results":[{"statement_id":0}]}
@@ -0,0 +1 @@
+{"error":"error parsing query: found SELEC, expected SELECT, DELETE, SHOW, CREATE, DROP, EXPLAIN, GRANT, REVOKE, ALTER, SET, KILL at line 1, char 1"}
@@ -0,0 +1,22 @@
+# ADR-001: Evolve the running baseline, plain Java
+
+Status: accepted · 2026-10-23
+
+## Context
+
+Two starting points: the code running on the Pi (`e345063`, ~1300 lines, plain Java 21, works
+since February) or a rewrite. The previous attempt (Spring Boot, branch
+`archive/spring-boot-attempt`) grew large and complex without doing the essential job: it was
+built on a register catalog that does not match the device.
+
+## Decision
+
+Keep the baseline and reshape it in small, deployable steps. Introduce the layers from the spec
+as code is touched. Stay on plain Java 21 without a framework; add a small library only when it
+removes more code than it adds, and record it here.
+
+## Consequences
+
+- What is proven on the device (decoding, sign handling, register addresses) is kept.
+- Every step can be compared against the current Grafana data.
+- No dependency-injection or web framework to learn before reading the code.
@@ -0,0 +1,19 @@
+# ADR-002: Backend on the Pi, server as the gateway
+
+Status: superseded by ADR-006 · 2026-10-23
+
+## Context
+
+The phone is outside the Krosno network. The backend could run on the Pi, next to the controller,
+or on my server and reach Modbus through WireGuard.
+
+## Decision
+
+The backend runs on the Pi. My server only routes and authenticates: Traefik forwards an
+authenticated HTTPS route through WireGuard to the Pi.
+
+## Consequences
+
+- Modbus never crosses the WAN: low latency, and the backend keeps running when the tunnel drops.
+- No pump logic on the server.
+- Deploy target stays the Pi (`scripts/deploy.sh`).
@@ -0,0 +1,25 @@
+# ADR-003: One Modbus owner; snapshot queries, queued commands
+
+Status: accepted · 2026-10-23
+
+## Context
+
+The controller answers slowly, and with frequent reads, commands were not carried out reliably.
+Several parts of the system want data at once (Influx export, API, health).
+
+## Decision
+
+- A single worker thread owns the only Modbus connection and talks to the controller in turn.
+- It polls at a fixed, conservative rate and publishes an immutable snapshot.
+- Queries (API, Influx export, health) read the snapshot only.
+- Commands go into a queue and get an id. The worker runs them between polls, reads the register
+  back and marks them `APPLIED` or `FAILED`. The client polls the command status.
+
+## Consequences
+
+- Load on the controller is fixed and set in one place, whatever the number of users.
+- Commands take seconds, not milliseconds; the UI shows them as pending.
+- The safe poll rate and command timing are measured in M2.
+- The MK01 gateway accepts one TCP client and a new one drops the old: each of our polls
+  disconnects the Frisko phone app. While the Frisko app is still in use, poll rarely (as now,
+  300 s) and keep each connection short.
@@ -0,0 +1,18 @@
+# ADR-004: Mobile-first web UI before any native app
+
+Status: accepted · 2026-10-23
+
+## Context
+
+The users are my parents, on their phones, away from home. A native app (React Native) or a
+WebView wrapper is possible later, but only once the backend works well.
+
+## Decision
+
+Build a mobile-first web UI, served by the backend, talking to the JSON API. Decide on native,
+WebView or web-only in M6, once real use shows what is missing.
+
+## Consequences
+
+- One API serves the web UI now and any app later.
+- Frontend technology is chosen in M3 with the same rule as ADR-001: the least code that works.
@@ -0,0 +1,25 @@
+# ADR-005: InfluxDB for data, one local file for pending restores, no other database
+
+Status: accepted · 2026-10-23
+
+## Context
+
+We store readings and energy data (time series), an audit log of writes (S3), and the state of
+running boosts: the value to restore and when (F3). InfluxDB 1.x already holds the history and
+feeds Grafana. It runs on my server, so the Pi loses it whenever the tunnel or DNS fails (D7).
+
+## Decision
+
+- **InfluxDB** holds all time series: heat pump readings and state, energy, and the audit log
+  as events. New data goes into new measurements, so existing Grafana dashboards keep working.
+- **One small JSON file on the Pi** holds the running boosts (register, previous value, restore
+  time), written atomically. A restore must work without the network.
+- Configuration (limits, presets, device addresses) is a file on the Pi, not data.
+- No other database. The command queue is in memory; a restart drops pending commands, and the
+  UI shows them as failed.
+
+## Consequences
+
+- Nothing new to install or back up besides one file.
+- Audit history in the app depends on InfluxDB; the journal on the Pi keeps a local copy.
+- If we ever need users, many records or complex queries, revisit this decision.
@@ -0,0 +1,40 @@
+# ADR-006: Thin gateway on the Pi, backend on the server in Kraków
+
+Status: accepted · 2026-10-23 · supersedes ADR-002
+
+## Context
+
+The Pi is the weakest part (SD card, Debian 11 without support). My server in Kraków runs
+Proxmox and Docker next to InfluxDB. But the MK01 gateway takes one client at a time, and a boost
+must be restored on time even when the tunnel is down.
+
+## Decision
+
+**Gateway (Pi)**, the only client of the devices, and nothing else:
+- polls every device (heat pump, Deye, Fronius, house meter, BME280 on the Pi) at a fixed rate, writes the readings
+  to InfluxDB with a local buffer, and serves the last snapshot (`GET /snapshot`);
+- accepts commands `register, value, minutes or until changed` (`POST /commands`) only from the
+  backend (token and firewall), checks them itself (allowlist, min/max, rate limit), writes,
+  reads back, reports `APPLIED` or `FAILED`;
+- keeps timed restores in a local file and runs them without the server.
+
+Restore rules:
+- The value to restore is read **from the controller just before the first write**, never sent
+  by the server.
+- A new boost on a register already boosted replaces the end time and keeps the original value.
+- At restore time, if the register no longer holds our value (someone changed it on the panel or
+  in the Frisko app), the gateway leaves it and reports a conflict.
+- After a restart, overdue restores run first.
+
+**Backend (Docker in Kraków)**: phone API, auth via Traefik, presets, notifications. Reads history
+from InfluxDB and the live snapshot from the gateway; sends commands only to the gateway.
+
+## Consequences
+
+- The baseline code evolves into the gateway (ADR-001); the backend is a new, separate app.
+- Two deployables: a Docker image for the server, a jar for the Pi.
+- While the tunnel is down the app shows no live data, but readings are buffered and restores
+  still happen on time.
+- `rpi-measurements` (house meter, BME280) moves into the gateway and is retired: one place for
+  all devices. The Pi's OS stays as it is (Debian 11), by decision.
+- Reading Deye and Fronius from the Pi needs the subnet overlap with Kraków fixed first (D7).
@@ -0,0 +1,29 @@
+# ADR-007: Gateway stack: JDK first, our own small Modbus core
+
+Status: accepted · 2026-10-23
+
+## Context
+
+The gateway talks to four kinds of devices: the heat pump (Modbus TCP, sign-magnitude), the
+house meter (Modbus TCP, FC4, float32), Deye (Modbus RTU inside Solarman V5 on port 8899) and
+Fronius (HTTP JSON), plus the BME280 on the Pi's I2C. No Java library speaks Solarman V5. The
+baseline uses modbus4j and influxdb-java; the latter pulls in most of the 10 MB jar.
+
+## Decision
+
+Java 21 (already on the Pi), Maven, a fat jar. As few dependencies as possible:
+
+| Area | Choice |
+|---|---|
+| Modbus | Our own package: FC3/FC4/FC6 codec with exceptions, a TCP transport and a Solarman V5 transport (RTU frame, CRC16). Readable as protocol documentation, tested with frames recorded from our devices. modbus4j is removed. |
+| Reading | Explicit register blocks per device in the config; one request per block, strictly one at a time per device, with a pause (200–300 ms for the heat pump). No automatic batching, no async pipelining. Devices run in parallel, one virtual thread each. |
+| InfluxDB | JDK `HttpClient`, line protocol to `/write`, our own buffer kept in a file. influxdb-java is removed. |
+| HTTP API | JDK `com.sun.net.httpserver` with virtual threads. |
+| JSON, config | Jackson. |
+| Logs, tests | slf4j-simple; JUnit 5, Mockito. |
+| BME280 | The kernel's IIO driver (`dtoverlay=i2c-sensor,bme280,addr=0x76` in `/boot/config.txt`, approved; applied in M1 with a planned reboot) and plain file reads from `/sys/bus/iio`. No library. |
+
+## Consequences
+
+- About 250 lines of protocol code we own, instead of two libraries; a much smaller jar.
+- Fallback for Modbus if our core disappoints: j2mod (Apache 2.0).
				`@@ -0,0 +1 @@`
				`{ "status": "APPLIED", "message": "cwu_economy 8 → 45, restore at 2026-10-24T12:00:00Z", "restoreAt": "2026-10-24T12:00:00Z" }`
				`@@ -0,0 +1 @@`
				`{ "status": "REJECTED", "message": "cwu_economy allows 5–48 in steps of 1, not 60", "restoreAt": null }`
				`@@ -0,0 +1 @@`
				`{ "setpoint": "cwu_economy", "value": 45, "hours": 2 }`
				`@@ -0,0 +1 @@`
				`{"status":"UP","devices":[{"name":"bme280","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"deye","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"fronius","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"heat-pump","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"house-meter","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null}]}`
				`@@ -0,0 +1 @@`
				`{"status":"DOWN","devices":[{"name":"bme280","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"deye","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"fronius","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null},{"name":"heat-pump","status":"DOWN","lastSuccess":null,"lastError":"Connection refused"},{"name":"house-meter","status":"UP","lastSuccess":"2026-10-23T22:26:00Z","lastError":null}]}`
				`@@ -0,0 +1 @@`
				[{"name":"bme280","interval":"PT5M","since":"2026-10-23T20:00:00Z","lastAttempt":"2026-10-23T22:26:00Z","lastSuccess":"2026-10-23T22:26:00Z","lastError":null,"readings":[{"database":"measurement","measurement":"MEASUREMENT","tags":{"location":"dom-szczepancowa"},"fields":{"pressure":985.8,"humidity":45.82,"temperature":20.17},"time":"2026-10-23T22:26:00Z"}]},{"name":"deye","interval":"PT1M","since":"2026-10-23T20:00:00Z","lastAttempt":"2026-10-23T22:26:00Z","lastSuccess":"2026-10-23T22:26:00Z","lastError":null,"readings":[{"database":"electricity","measurement":"deye","tags":{"location":"dom-szczepancowa"},"fields":{"grid_power_w":645.0,"battery_temperature_c":19.2,"battery_discharge_today_kwh":0.1,"load_today_kwh":24.2,"pv2_power_w":0.0,"pv1_power_w":0.0,"grid_voltage_l1_v":233.9,"grid_bought_today_kwh":16.8,"load_power_w":570.0,"grid_voltage_l2_v":233.4,"battery_soc_pct":99.0,"pv_today_kwh":29.9,"battery_power_w":-24.0,"grid_power_l1_w":390.0,"grid_voltage_l3_v":231.9,"battery_charge_today_kwh":0.5,"grid_power_l2_w":52.0,"load_power_l1_w":364.0,"load_power_l2_w":26.0,"grid_power_l3_w":203.0,"battery_voltage_v":56.49,"grid_sold_today_kwh":22.3,"load_power_l3_w":180.0},"time":"2026-10-23T22:26:00Z"}]},{"name":"fronius","interval":"PT1M","since":"2026-10-23T20:00:00Z","lastAttempt":"2026-10-23T22:26:00Z","lastSuccess":"2026-10-23T22:26:00Z","lastError":null,"readings":[{"database":"electricity","measurement":"fronius","tags":{"location":"dom-szczepancowa"},"fields":{"energy_year_wh":1846276.375,"pv_power_w":0.0,"energy_day_wh":4400.0,"energy_total_wh":2.90713E7},"time":"2026-10-23T22:26:00Z"}]},{"name":"heat-pump","interval":"PT10S","since":"2026-10-23T20:00:00Z","lastAttempt":"2026-10-23T22:26:00Z","lastSuccess":"2026-10-23T22:26:00Z","lastError":null,"readings":[{"database":"Dom_Pompa","measurement":"POMPA","tags":{},"fields":{"Temp co":16.900000000000002,"Temp cwu":13.600000000000001,"Temp out":14.3,"Temp in":16.0,"Temp wew":21.200000000000003,"External temperature":4.3,"Temp zsr":4.800000000000001,"Temp pc out":19.700000000000003},"time":"2026-10-23T22:26:00Z"},{"database":"Dom_Pompa","measurement":"heat_pump","tags":{},"fields":{"pump_outlet_temp":19.700000000000003,"setpoint_cwu_economy":8.0,"pressure_switch":0.0,"setpoint_co_comfort":19.0,"output_co":0.0,"co_buffer_temp":16.900000000000002,"ground_out_temp":14.3,"setpoint_co_economy":18.0,"output_heater":0.0,"pump_mode":0.0,"target_co_temp":31.0,"cwu_temp":13.600000000000001,"alarm":0.0,"reg_4225":0.0,"reg_4223":0.0,"reg_4224":0.0,"reg_4222":0.0,"target_room_temp":18.0,"output_circulation":0.0,"output_compressor":0.0,"output_ground":0.0,"outdoor_avg_temp":4.800000000000001,"program":0.0,"output_cwu":0.0,"target_cwu_temp":8.0,"indoor_temp":21.200000000000003,"output_buffer":0.0,"setpoint_cwu_comfort":45.0,"output_cooling":0.0,"zb_state":0.0,"outdoor_temp":4.3,"ground_in_temp":16.0},"time":"2026-10-23T22:26:00Z"}]},{"name":"house-meter","interval":"PT1M","since":"2026-10-23T20:00:00Z","lastAttempt":"2026-10-23T22:26:00Z","lastSuccess":"2026-10-23T22:26:00Z","lastError":null,"readings":[{"database":"electricity","measurement":"PRAD2","tags":{"location":"dom-szczepancowa"},"fields":{"p3_power_reactive":26.52,"p2_demand_current":0.98,"total_power_factor":1.0,"p23_voltage_thd":0.0,"import_energy_reactive":6433.02,"maximum_export_demand_power_active":0.0,"total_energy_apparent":138275.8,"p1_power_apparent":74.71,"p3_demand_current":0.86,"p2_current_thd":99.27,"total_current":262147.94,"p2_power_factor":0.87,"p1_power_factor":0.75,"p3_current":0.67,"p2_current":0.88,"total_energy_active":134191.39,"maximum_neutral_demand_current":20.28,"maximum_import_demand_power_active":0.0,"voltage_ln_thd":3.65,"p2_power_apparent":207.46,"p1_phase_angle":41.52,"export_demand_power_active":0.0,"maximum_p1_demand_current":21.31,"neutral_demand_current":0.77,"p31_voltage_thd":0.0,"p3_power_apparent":155.65,"neutral_current":0.67,"export_energy_active":66677.11,"total_phase_angle":-4.12,"import_demand_power_active":0.0,"maximum_import_demand_power_apparent":-10986.21,"current_thd":95.36,"maximum_p2_demand_current":20.79,"p23_voltage":405.05,"p3_power_active":153.38,"p2_power_active":179.47,"p3_voltage":232.2,"p2_voltage":235.51,"frequency":50.01,"maximum_p3_demand_current":16.35,"p12_voltage":408.07,"maximum_demand_power_apparent":10989.65,"p1_demand_current":0.33,"p3_current_thd":72.45,"total_power_apparent":437.82,"voltage_ln":234.47,"voltage_ll_thd":0.0,"voltage_ll":406.11,"p2_phase_angle":-30.11,"p3_power_factor":0.99,"p1_current":0.32,"export_energy_reactive":26926.61,"total_power_reactive":-28.04,"p12_voltage_thd":0.0,"import_energy_active":67514.27,"p31_voltage":405.21,"p1_current_thd":114.36,"total_energy_reactive":33359.63,"total_demand_power_apparent":507.11,"p1_power_reactive":49.52,"current_ln":0.85,"total_power_active":388.78,"p1_voltage":235.69,"p2_power_reactive":-104.07,"p3_phase_angle":9.81,"p3n_voltage_thd":3.64,"p2n_voltage_thd":3.82,"p1n_voltage_thd":3.48,Line truncated
				`@@ -0,0 +1 @@`
				`{"results":[{"statement_id":0,"series":[{"name":"POMPA","columns":["time","mean"],"values":[[1792771200000,43.76666666666667],[1792774800000,42.40000000000001],[1792778400000,26.733333333333334],[1792782000000,19.15833333333333],[1792785600000,13.799999999999997],[1792789200000,13.58333333333333],[1792792800000,13.65]]}]}]}`
				`@@ -0,0 +1 @@`
				`{"error":"error parsing query: found SELEC, expected SELECT, DELETE, SHOW, CREATE, DROP, EXPLAIN, GRANT, REVOKE, ALTER, SET, KILL at line 1, char 1"}`