diff --git a/overlays/default.nix b/overlays/default.nix
index 51f646b..0d27c4e 100644
--- a/overlays/default.nix
+++ b/overlays/default.nix
@@ -23,9 +23,11 @@
         apscheduler
         fastapi
         fastapi-cli
+        httpx
         mypy
         polars
         psycopg
+        pydantic
         pyfakefs
         pytest
         pytest-cov
@@ -37,6 +39,7 @@
         sqlalchemy
         sqlalchemy
         textual
+        tinytuya
         typer
         types-requests
       ]
diff --git a/pyproject.toml b/pyproject.toml
index dc108df..87d19c3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ requires-python = "~=3.13.0"
 readme = "README.md"
 license = "MIT"
 # these dependencies are a best effort and aren't guaranteed to work
-dependencies = ["apprise", "apscheduler", "polars", "requests", "typer"]
+dependencies = ["apprise", "apscheduler", "httpx", "polars", "pydantic", "pyyaml", "requests", "typer"]
 
 [dependency-groups]
 dev = [
@@ -55,6 +55,9 @@ lint.ignore = [
 "python/orm/**" = [
     "TC003", # (perm) this creates issues because sqlalchemy uses these at runtime
 ]
+"python/congress_tracker/**" = [
+    "TC003", # (perm) this creates issues because sqlalchemy uses these at runtime
+]
 "python/alembic/**" = [
     "INP001", # (perm) this creates LSP issues for alembic
 ]
diff --git a/python/heater/__init__.py b/python/heater/__init__.py
new file mode 100644
index 0000000..26c1925
--- /dev/null
+++ b/python/heater/__init__.py
@@ -0,0 +1 @@
+"""Tuya heater control service."""
diff --git a/python/heater/controller.py b/python/heater/controller.py
new file mode 100644
index 0000000..e369921
--- /dev/null
+++ b/python/heater/controller.py
@@ -0,0 +1,68 @@
+"""TinyTuya device controller for heater."""
+
+import logging
+
+import tinytuya
+
+from python.heater.models import ActionResult, DeviceConfig, HeaterStatus
+
+logger = logging.getLogger(__name__)
+
+# DPS mapping for heater
+DPS_POWER = "1"  # bool: on/off
+DPS_SETPOINT = "101"  # int: target temp (read-only)
+DPS_STATE = "102"  # str: "Stop", "Heat", etc.
+DPS_UNKNOWN = "104"  # int: unknown
+DPS_ERROR = "108"  # int: last error code
+
+
+class HeaterController:
+    """Controls a Tuya heater device via local network."""
+
+    def __init__(self, config: DeviceConfig) -> None:
+        self.device = tinytuya.Device(config.device_id, config.ip, config.local_key)
+        self.device.set_version(config.version)
+        self.device.set_socketTimeout(0.5)
+        self.device.set_socketRetryLimit(1)
+
+    def status(self) -> HeaterStatus:
+        """Get current heater status."""
+        data = self.device.status()
+
+        if "Error" in data:
+            logger.error("Device error: %s", data)
+            return HeaterStatus(power=False, raw_dps={"error": data["Error"]})
+
+        dps = data.get("dps", {})
+        return HeaterStatus(
+            power=bool(dps.get(DPS_POWER, False)),
+            setpoint=dps.get(DPS_SETPOINT),
+            state=dps.get(DPS_STATE),
+            error_code=dps.get(DPS_ERROR),
+            raw_dps=dps,
+        )
+
+    def turn_on(self) -> ActionResult:
+        """Turn heater on."""
+        try:
+            self.device.set_value(DPS_POWER, True)
+            return ActionResult(success=True, action="on", power=True)
+        except Exception as error:
+            logger.exception("Failed to turn on")
+            return ActionResult(success=False, action="on", error=str(error))
+
+    def turn_off(self) -> ActionResult:
+        """Turn heater off."""
+        try:
+            self.device.set_value(DPS_POWER, False)
+            return ActionResult(success=True, action="off", power=False)
+        except Exception as error:
+            logger.exception("Failed to turn off")
+            return ActionResult(success=False, action="off", error=str(error))
+
+    def toggle(self) -> ActionResult:
+        """Toggle heater power state."""
+        status = self.status()
+        if status.power:
+            return self.turn_off()
+        return self.turn_on()
diff --git a/python/heater/main.py b/python/heater/main.py
new file mode 100644
index 0000000..0d7ecf7
--- /dev/null
+++ b/python/heater/main.py
@@ -0,0 +1,85 @@
+"""FastAPI heater control service."""
+
+import logging
+from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
+from typing import Annotated
+
+import typer
+import uvicorn
+from fastapi import FastAPI, HTTPException
+
+from python.common import configure_logger
+from python.heater.controller import HeaterController
+from python.heater.models import ActionResult, DeviceConfig, HeaterStatus
+
+logger = logging.getLogger(__name__)
+
+
+def create_app(config: DeviceConfig) -> FastAPI:
+    """Create FastAPI application."""
+
+    @asynccontextmanager
+    async def lifespan(app: FastAPI) -> AsyncIterator[None]:
+        app.state.controller = HeaterController(config)
+        yield
+
+    app = FastAPI(
+        title="Heater Control API",
+        description="Fast local control for Tuya heater",
+        lifespan=lifespan,
+    )
+
+    @app.get("/status")
+    def get_status() -> HeaterStatus:
+        return app.state.controller.status()
+
+    @app.post("/on")
+    def heater_on() -> ActionResult:
+        result = app.state.controller.turn_on()
+        if not result.success:
+            raise HTTPException(status_code=500, detail=result.error)
+        return result
+
+    @app.post("/off")
+    def heater_off() -> ActionResult:
+        result = app.state.controller.turn_off()
+        if not result.success:
+            raise HTTPException(status_code=500, detail=result.error)
+        return result
+
+    @app.post("/toggle")
+    def heater_toggle() -> ActionResult:
+        result = app.state.controller.toggle()
+        if not result.success:
+            raise HTTPException(status_code=500, detail=result.error)
+        return result
+
+    return app
+
+
+def serve(
+    host: Annotated[str, typer.Option("--host", "-h", help="Host to bind to")],
+    port: Annotated[int, typer.Option("--port", "-p", help="Port to bind to")] = 8124,
+    log_level: Annotated[str, typer.Option("--log-level", "-l", help="Log level")] = "INFO",
+    device_id: Annotated[str | None, typer.Option("--device-id", envvar="TUYA_DEVICE_ID")] = None,
+    device_ip: Annotated[str | None, typer.Option("--device-ip", envvar="TUYA_DEVICE_IP")] = None,
+    local_key: Annotated[str | None, typer.Option("--local-key", envvar="TUYA_LOCAL_KEY")] = None,
+) -> None:
+    """Start the heater control API server."""
+    configure_logger(log_level)
+
+    logger.info("Starting heater control API server")
+
+    if not device_id or not device_ip or not local_key:
+        error = "Must provide device ID, IP, and local key"
+        raise typer.Exit(error)
+
+    config = DeviceConfig(device_id=device_id, ip=device_ip, local_key=local_key)
+
+    app = create_app(config)
+    uvicorn.run(app, host=host, port=port)
+
+
+if __name__ == "__main__":
+    typer.run(serve)
diff --git a/python/heater/models.py b/python/heater/models.py
new file mode 100644
index 0000000..23c050a
--- /dev/null
+++ b/python/heater/models.py
@@ -0,0 +1,31 @@
+"""Pydantic models for heater API."""
+
+from pydantic import BaseModel, Field
+
+
+class DeviceConfig(BaseModel):
+    """Tuya device configuration."""
+
+    device_id: str
+    ip: str
+    local_key: str
+    version: float = 3.5
+
+
+class HeaterStatus(BaseModel):
+    """Current heater status."""
+
+    power: bool
+    setpoint: int | None = None
+    state: str | None = None  # "Stop", "Heat", etc.
+    error_code: int | None = None
+    raw_dps: dict[str, object] = Field(default_factory=dict)
+
+
+class ActionResult(BaseModel):
+    """Result of a heater action."""
+
+    success: bool
+    action: str
+    power: bool | None = None
+    error: str | None = None
diff --git a/systems/brain/services/heater.nix b/systems/brain/services/heater.nix
new file mode 100644
index 0000000..94bc21f
--- /dev/null
+++ b/systems/brain/services/heater.nix
@@ -0,0 +1,33 @@
+{
+  pkgs,
+  inputs,
+  ...
+}:
+{
+  networking.firewall.allowedTCPPorts = [ 8124 ];
+
+  systemd.services.heater-api = {
+    description = "Tuya Heater Control API";
+    after = [ "network.target" ];
+    wantedBy = [ "multi-user.target" ];
+
+      environment = {
+        PYTHONPATH = "${inputs.self}/";
+      };
+
+    serviceConfig = {
+      Type = "simple";
+      ExecStart = "${pkgs.my_python}/bin/python -m python.heater.main --host 0.0.0.0 --port 8124";
+      EnvironmentFile = "/etc/heater.env";
+      Restart = "on-failure";
+      RestartSec = "5s";
+      StandardOutput = "journal";
+      StandardError = "journal";
+      NoNewPrivileges = true;
+      ProtectSystem = "strict";
+      ProtectHome = "read-only";
+      PrivateTmp = true;
+      ReadOnlyPaths = [ "${inputs.self}" ];
+    };
+  };
+}
diff --git a/systems/brain/services/home_assistant.nix b/systems/brain/services/home_assistant.nix
index 5676052..ee8b7f5 100644
--- a/systems/brain/services/home_assistant.nix
+++ b/systems/brain/services/home_assistant.nix
@@ -22,6 +22,7 @@
             victron_modbuss = "!include ${./home_assistant/victron_modbuss.yaml}";
             battery_sensors = "!include ${./home_assistant/battery_sensors.yaml}";
             gps_location = "!include ${./home_assistant/gps_location.yaml}";
+            heater = "!include ${./home_assistant/heater.yaml}";
             van_weather = "!include ${./home_assistant/van_weather_template.yaml}";
           };
         };
@@ -71,6 +72,7 @@
           pymetno # for met.no weather
           uiprotect # for ubiquiti integration
           unifi-discovery # for ubiquiti integration
+          jsonpath # for rest sensors
         ];
       extraComponents = [ "isal" ];
       customComponents = with pkgs.home-assistant-custom-components; [
diff --git a/systems/brain/services/home_assistant/heater.yaml b/systems/brain/services/home_assistant/heater.yaml
new file mode 100644
index 0000000..0bcfbc6
--- /dev/null
+++ b/systems/brain/services/home_assistant/heater.yaml
@@ -0,0 +1,41 @@
+rest:
+  - resource: http://localhost:8124/status
+    scan_interval: 30
+    sensor:
+      - name: "Heater Setpoint"
+        unique_id: heater_setpoint
+        value_template: "{{ value_json.setpoint }}"
+        unit_of_measurement: "F"
+        device_class: temperature
+      - name: "Heater State"
+        unique_id: heater_state
+        value_template: "{{ value_json.state }}"
+      - name: "Heater Error Code"
+        unique_id: heater_error_code
+        value_template: "{{ value_json.error_code }}"
+    binary_sensor:
+      - name: "Heater Power"
+        unique_id: heater_power
+        value_template: "{{ value_json.power }}"
+        device_class: running
+
+rest_command:
+  heater_on:
+    url: http://localhost:8124/on
+    method: POST
+  heater_off:
+    url: http://localhost:8124/off
+    method: POST
+  heater_toggle:
+    url: http://localhost:8124/toggle
+    method: POST
+
+template:
+  - switch:
+      - unique_id: heater_switch
+        name: Heater
+        state: "{{ is_state('binary_sensor.heater_power', 'on') }}"
+        turn_on:
+          - action: rest_command.heater_on
+        turn_off:
+          - action: rest_command.heater_off