diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d75e14..33862ce 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.8.6] - 2025-12-17
+
+### Fixed
+
+- **Housekeeper API paths** - Updated all client endpoints to use `/housekeeping/` prefix to match core-api routes
+- **Housekeeper entity hallucination** - Improved system prompt with critical rule requiring `list_devices()` before any control action to prevent guessing entity IDs
+
+### Added
+
+- **Housekeeping API spec** - Added `docs/housekeeping-api-spec.md` documenting the core-api home automation interface
+
 ## [1.8.5] - 2025-12-16
 
 ### Fixed
diff --git a/docs/housekeeping-api-spec.md b/docs/housekeeping-api-spec.md
new file mode 100644
index 0000000..79dfe34
--- /dev/null
+++ b/docs/housekeeping-api-spec.md
@@ -0,0 +1,317 @@
+# Home Automation API Interface Specification
+
+## Purpose
+
+This document specifies the expected endpoints for a home automation abstraction layer in core-api. These endpoints will be consumed by the Tatlock Housekeeper agent and potentially other projects (scheduler, dashboards).
+
+The goal is to provide a simplified, domain-specific interface for home automation that abstracts away the underlying platform (initially Home Assistant, but swappable).
+
+---
+
+## Endpoints
+
+### Device Discovery
+
+#### `GET /housekeeping/devices`
+
+List available devices.
+
+**Query Parameters:**
+- `domain` (optional): Filter by device type (e.g., `light`, `switch`, `climate`, `media_player`)
+- `area` (optional): Filter by area/room name
+
+**Response:**
+```json
+{
+  "devices": [
+    {
+      "entity_id": "light.living_room",
+      "name": "Living Room Light",
+      "domain": "light",
+      "area": "Living Room",
+      "state": "on",
+      "attributes": {
+        "brightness": 255,
+        "color_temp": 370
+      }
+    }
+  ]
+}
+```
+
+---
+
+#### `GET /housekeeping/devices/{entity_id}`
+
+Get detailed state of a specific device.
+
+**Response:**
+```json
+{
+  "entity_id": "light.living_room",
+  "name": "Living Room Light",
+  "domain": "light",
+  "area": "Living Room",
+  "state": "on",
+  "attributes": {
+    "brightness": 255,
+    "color_temp": 370,
+    "supported_features": ["brightness", "color_temp"]
+  },
+  "last_changed": "2025-12-16T10:30:00Z"
+}
+```
+
+---
+
+#### `GET /housekeeping/areas`
+
+List all areas/rooms.
+
+**Response:**
+```json
+{
+  "areas": [
+    {"id": "living_room", "name": "Living Room"},
+    {"id": "bedroom", "name": "Bedroom"},
+    {"id": "kitchen", "name": "Kitchen"}
+  ]
+}
+```
+
+---
+
+### Device Control
+
+#### `POST /housekeeping/devices/{entity_id}/control`
+
+Control a device (turn on, turn off, toggle, or set attributes).
+
+**Request Body:**
+```json
+{
+  "action": "turn_on",
+  "brightness": 128,
+  "color_temp": 400
+}
+```
+
+- `action` (required): One of `turn_on`, `turn_off`, `toggle`
+- Additional attributes vary by device type (brightness, color_temp, rgb_color, etc.)
+
+**Response:**
+```json
+{
+  "success": true,
+  "entity_id": "light.living_room",
+  "new_state": "on",
+  "message": "Light turned on"
+}
+```
+
+---
+
+### Scenes
+
+#### `GET /housekeeping/scenes`
+
+List available scenes.
+
+**Response:**
+```json
+{
+  "scenes": [
+    {"id": "scene.movie_night", "name": "Movie Night"},
+    {"id": "scene.good_morning", "name": "Good Morning"},
+    {"id": "scene.all_off", "name": "All Off"}
+  ]
+}
+```
+
+---
+
+#### `POST /housekeeping/scenes/{scene_id}/activate`
+
+Activate a scene.
+
+**Response:**
+```json
+{
+  "success": true,
+  "scene_id": "scene.movie_night",
+  "message": "Scene activated"
+}
+```
+
+---
+
+### Scripts
+
+#### `GET /housekeeping/scripts`
+
+List available scripts/sequences.
+
+**Response:**
+```json
+{
+  "scripts": [
+    {"id": "script.bedtime_routine", "name": "Bedtime Routine"},
+    {"id": "script.welcome_home", "name": "Welcome Home"}
+  ]
+}
+```
+
+---
+
+#### `POST /housekeeping/scripts/{script_id}/run`
+
+Execute a script with optional variables.
+
+**Request Body (optional):**
+```json
+{
+  "variables": {
+    "brightness_level": 50,
+    "target_room": "bedroom"
+  }
+}
+```
+
+**Response:**
+```json
+{
+  "success": true,
+  "script_id": "script.bedtime_routine",
+  "message": "Script executed"
+}
+```
+
+---
+
+### Automations
+
+#### `GET /housekeeping/automations`
+
+List automations and their enabled/disabled status.
+
+**Response:**
+```json
+{
+  "automations": [
+    {
+      "id": "automation.motion_lights",
+      "name": "Motion Lights",
+      "enabled": true
+    },
+    {
+      "id": "automation.night_mode",
+      "name": "Night Mode",
+      "enabled": false
+    }
+  ]
+}
+```
+
+---
+
+#### `POST /housekeeping/automations/{automation_id}/toggle`
+
+Enable or disable an automation.
+
+**Request Body:**
+```json
+{
+  "enabled": true
+}
+```
+
+**Response:**
+```json
+{
+  "success": true,
+  "automation_id": "automation.motion_lights",
+  "enabled": true,
+  "message": "Automation enabled"
+}
+```
+
+---
+
+### Utility
+
+#### `GET /housekeeping/history`
+
+Get state history for a device.
+
+**Query Parameters:**
+- `entity_id` (required): Device to get history for
+- `hours` (optional, default 24): Hours of history to retrieve
+
+**Response:**
+```json
+{
+  "entity_id": "light.living_room",
+  "history": [
+    {
+      "state": "on",
+      "timestamp": "2025-12-16T10:30:00Z",
+      "attributes": {"brightness": 255}
+    },
+    {
+      "state": "off",
+      "timestamp": "2025-12-16T08:00:00Z",
+      "attributes": {}
+    }
+  ]
+}
+```
+
+---
+
+#### `GET /housekeeping/health`
+
+Health check for home automation connection.
+
+**Response:**
+```json
+{
+  "status": "healthy",
+  "connected": true,
+  "platform": "home_assistant",
+  "version": "2024.12.0"
+}
+```
+
+---
+
+## Error Responses
+
+All endpoints should return consistent error responses:
+
+```json
+{
+  "error": true,
+  "code": "DEVICE_NOT_FOUND",
+  "message": "Device light.nonexistent not found"
+}
+```
+
+Common error codes:
+- `DEVICE_NOT_FOUND` - Entity ID doesn't exist
+- `INVALID_ACTION` - Unsupported action for device type
+- `CONNECTION_ERROR` - Cannot reach home automation platform
+- `UNAUTHORIZED` - Invalid or missing credentials
+
+---
+
+## Authentication
+
+All endpoints require authentication via Bearer token in the `Authorization` header.
+
+---
+
+## Consuming Client
+
+The Tatlock project has an existing client (`src/agents/housekeeper/client.py`) that expects these endpoints. No changes to Tatlock are needed once these endpoints are available.
+
+Reference: `CoreAPIClient` class in Tatlock expects these exact endpoint patterns.
diff --git a/pyproject.toml b/pyproject.toml
index 5d6c014..6663199 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "tatlock"
-version = "1.8.5"
+version = "1.8.6"
 description = "OpenAI-compatible API with Ollama backend"
 requires-python = ">=3.12"
 dependencies = []
diff --git a/src/agents/housekeeper/agent.py b/src/agents/housekeeper/agent.py
index 7d3bc5f..cef931a 100644
--- a/src/agents/housekeeper/agent.py
+++ b/src/agents/housekeeper/agent.py
@@ -74,21 +74,35 @@ Your role is to help users control and monitor their smart home through Home Ass
 ### History Tools
 - **get_history**: Check a device's state history
 
+## Critical Rules
+
+**NEVER GUESS ENTITY IDs.** You do not know what devices exist. Entity IDs vary between
+installations. You MUST call list_devices() FIRST to discover actual entity_ids before
+ANY control action (turn_on, turn_off, toggle).
+
+Wrong approach:
+  User: "Turn off the study lights"
+  You: turn_off("light.study")  ← WRONG! You guessed the entity_id
+
+Correct approach:
+  User: "Turn off the study lights"
+  You: list_devices(domain="light")  ← First discover what exists
+  You: [See results like light.study_main, light.study]
+  You: turn_off("light.study_main"), turn_off("light.study")  ← Use actual IDs
+
 ## Best Practices
 
-1. **Device Discovery First**: If the user asks about devices without being specific,
-   use list_devices to find what's available before acting.
+1. **ALWAYS list_devices first** before any control action. No exceptions.
+   Filter by domain and/or area to narrow results.
 
-2. **Confirm State After Actions**: After turning something on/off, you can verify
-   with get_device_state if needed.
+2. **Use exact entity_ids** from list_devices results. Never construct or guess them.
 
-3. **Use Entity IDs**: Devices are identified by entity_id (e.g., light.living_room).
-   Always use the exact entity_id from list_devices.
+3. **Area-aware filtering**: Use area parameter when users mention a room.
+   Note: Some devices may have area=None but contain the room name in entity_id.
 
-4. **Area-Aware**: When users say "living room lights", filter by area="living_room".
+4. **Verify after actions**: Use get_device_state to confirm state changes if needed.
 
-5. **Safety**: For actions affecting multiple devices or automations, summarize
-   what you're about to do.
+5. **Safety for bulk actions**: When affecting multiple devices, summarize first.
 
 ## Common Patterns
 
diff --git a/src/agents/housekeeper/client.py b/src/agents/housekeeper/client.py
index c1211a4..db50f97 100644
--- a/src/agents/housekeeper/client.py
+++ b/src/agents/housekeeper/client.py
@@ -182,7 +182,7 @@ class CoreAPIClient:
 
         logger.debug("core_api_list_devices", domain=domain, area=area)
 
-        response = await client.get("/devices", params=params or None)
+        response = await client.get("/housekeeping/devices", params=params or None)
         response.raise_for_status()
 
         data = response.json()
@@ -199,7 +199,7 @@ class CoreAPIClient:
 
         logger.debug("core_api_list_areas")
 
-        response = await client.get("/areas")
+        response = await client.get("/housekeeping/areas")
         response.raise_for_status()
 
         data = response.json()
@@ -219,7 +219,7 @@ class CoreAPIClient:
 
         logger.debug("core_api_get_state", entity_id=entity_id)
 
-        response = await client.get(f"/entities/{entity_id}")
+        response = await client.get(f"/housekeeping/devices/{entity_id}")
         response.raise_for_status()
 
         return DeviceState(**response.json())
@@ -260,7 +260,7 @@ class CoreAPIClient:
         logger.info("core_api_turn_on", entity_id=entity_id, payload=payload)
 
         response = await client.post(
-            f"/devices/{entity_id}/control",
+            f"/housekeeping/devices/{entity_id}/control",
             json=payload,
         )
         response.raise_for_status()
@@ -288,7 +288,7 @@ class CoreAPIClient:
         logger.info("core_api_turn_off", entity_id=entity_id)
 
         response = await client.post(
-            f"/devices/{entity_id}/control",
+            f"/housekeeping/devices/{entity_id}/control",
             json={"action": "turn_off"},
         )
         response.raise_for_status()
@@ -316,7 +316,7 @@ class CoreAPIClient:
         logger.info("core_api_toggle", entity_id=entity_id)
 
         response = await client.post(
-            f"/devices/{entity_id}/control",
+            f"/housekeeping/devices/{entity_id}/control",
             json={"action": "toggle"},
         )
         response.raise_for_status()
@@ -344,7 +344,7 @@ class CoreAPIClient:
 
         logger.debug("core_api_list_scenes")
 
-        response = await client.get("/scenes")
+        response = await client.get("/housekeeping/scenes")
         response.raise_for_status()
 
         data = response.json()
@@ -364,7 +364,7 @@ class CoreAPIClient:
 
         logger.info("core_api_activate_scene", scene_id=scene_id)
 
-        response = await client.post(f"/scenes/{scene_id}/activate")
+        response = await client.post(f"/housekeeping/scenes/{scene_id}/activate")
         response.raise_for_status()
 
         data = response.json()
@@ -390,7 +390,7 @@ class CoreAPIClient:
 
         logger.debug("core_api_list_scripts")
 
-        response = await client.get("/scripts")
+        response = await client.get("/housekeeping/scripts")
         response.raise_for_status()
 
         data = response.json()
@@ -420,7 +420,7 @@ class CoreAPIClient:
         logger.info("core_api_run_script", script_id=script_id)
 
         response = await client.post(
-            f"/scripts/{script_id}/run",
+            f"/housekeeping/scripts/{script_id}/run",
             json=payload or None,
         )
         response.raise_for_status()
@@ -448,7 +448,7 @@ class CoreAPIClient:
 
         logger.debug("core_api_list_automations")
 
-        response = await client.get("/automations")
+        response = await client.get("/housekeeping/automations")
         response.raise_for_status()
 
         data = response.json()
@@ -478,7 +478,7 @@ class CoreAPIClient:
         )
 
         response = await client.post(
-            f"/automations/{automation_id}/toggle",
+            f"/housekeeping/automations/{automation_id}/toggle",
             json={"enable": enable},
         )
         response.raise_for_status()
@@ -515,7 +515,7 @@ class CoreAPIClient:
         logger.debug("core_api_get_history", entity_id=entity_id, hours=hours)
 
         response = await client.get(
-            "/history",
+            "/housekeeping/history",
             params={"entity_id": entity_id, "hours": hours},
         )
         response.raise_for_status()
@@ -536,7 +536,7 @@ class CoreAPIClient:
         """
         try:
             client = self._ensure_client()
-            response = await client.get("/health")
+            response = await client.get("/housekeeping/health")
             return response.status_code == 200
         except Exception as e:
             logger.warning("core_api_health_check_failed", error=str(e))