Add MQTT/OwnTracks workflow for location tracking

- Add tracker-mqtt.json: New n8n workflow for MQTT-based location data
- MQTT workflow subscribes to owntracks/# topic
- Transforms OwnTracks data format to NocoDB schema
- Stores locations in same database as Telegram workflow
- Update CLAUDE.md with MQTT workflow documentation
- Add OwnTracks integration guide and data mapping details

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -4,36 +4,80 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Overview
 
-This repository contains an n8n workflow configuration (`tracker.json`) that implements a Telegram-based location tracking system without a database. The workflow stores location data in a simple JSON file (`/tmp/n8n-locations.json`) on the n8n server.
+This repository contains three n8n workflow configurations for location tracking:
+
+1. **tracker.json** - Telegram-based with file storage using `/tmp/n8n-locations.json` (simpler, no database required)
+2. **tracker-db.json** - Telegram-based with NocoDB storage (production-ready, persistent storage)
+3. **tracker-mqtt.json** - MQTT-based with NocoDB storage (for OwnTracks/MQTT location data)
+
+The Telegram workflows share the same architecture but differ in storage backend. The MQTT workflow integrates OwnTracks-compatible location data into the same NocoDB database.
 
 ## Workflow Architecture
 
-The workflow has two main execution paths:
+### Telegram-based Workflows
 
-### 1. Location Capture Flow (Telegram Trigger → Storage)
+Both Telegram workflows have two main execution paths:
+
+**1. Location Capture Flow (Telegram Trigger → Storage)**
+
+tracker.json (File-based):
+- Telegram Trigger → Hat Location? → Location verarbeiten → Lade existierende Daten → Merge mit History → Speichere in File → Telegram Bestätigung
+
+tracker-db.json (NocoDB-based):
+- Telegram Trigger → Hat Location? → Location verarbeiten → Speichere in NocoDB → [Hole letzten Eintrag + Zähle Einträge] → Merge → Bereite Bestätigung vor → Telegram Bestätigung
+
+Key nodes:
 - **Telegram Trigger**: Receives incoming Telegram messages
 - **Hat Location?**: Filters messages containing location data
-- **Location verarbeiten**: Extracts and formats location data (lat/lon, user info, timestamp)
-- **Lade existierende Daten**: Reads existing locations from `/tmp/n8n-locations.json`
-- **Merge mit History**: Combines new location with existing data (keeps last 100 entries)
-- **Speichere in File**: Writes updated JSON back to `/tmp/n8n-locations.json`
-- **Telegram Bestätigung**: Sends confirmation message with location details and map link
+- **Location verarbeiten**: Extracts and formats location data (lat/lon, user info, timestamp) using JavaScript
+- **Storage**: Either file-based (shell commands) or NocoDB API calls
+- **Telegram Bestätigung**: Sends confirmation with location details and map link
 
-### 2. Location API Flow (Webhook → JSON Response)
-- **Webhook - Location API**: Exposes `/location` endpoint with CORS enabled
-- **Lade Daten für API**: Reads location data from file
-- **Format API Response**: Formats data into structured JSON (current location, history, metadata)
-- **JSON Response**: Returns JSON with CORS headers
+**2. Location API Flow (Webhook → JSON Response)** - See section below
+
+### MQTT-based Workflow
+
+**tracker-mqtt.json** has a simpler, single-path architecture:
+
+MQTT Trigger → Ist Location? → MQTT Location verarbeiten → Speichere in NocoDB
+
+Key nodes:
+- **MQTT Trigger**: Subscribes to MQTT topic `owntracks/#` (OwnTracks-compatible)
+- **Ist Location?**: Filters for messages with `_type: "location"`
+- **MQTT Location verarbeiten**: Transforms MQTT/OwnTracks data format to match NocoDB schema
+- **Speichere in NocoDB**: Stores location in same database as Telegram data
+
+### Location API Flow (Shared)
+
+**tracker.json (File-based)**:
+- Webhook - Location API → Lade Daten für API (shell: cat) → Format API Response → JSON Response
+
+**tracker-db.json (NocoDB-based)**:
+- Webhook - Location API → Lade Daten aus NocoDB → Format API Response → JSON Response
+
+Both expose `/location` endpoint with CORS enabled, returning current location, history, and metadata. The MQTT workflow shares the same NocoDB database and thus the same API.
 
 ## Key Technical Details
 
 ### Data Storage
-- Storage location: `/tmp/n8n-locations.json`
+
+**tracker.json (File-based)**:
+- Location: `/tmp/n8n-locations.json`
 - Format: JSON array of location objects
 - Max retention: 100 most recent locations (oldest automatically removed)
-- Data persistence: File-based (survives n8n restarts but may be lost on system restart due to `/tmp` location)
+- Persistence: Survives n8n restarts but may be lost on system restart due to `/tmp` location
+
+**tracker-db.json & tracker-mqtt.json (NocoDB)**:
+- Location: NocoDB database (Project: `pdxl4cx4dbu9nxi`, Table: `m8pqj5ixgnnrzkg`)
+- Format: NocoDB records (no client-side limit)
+- Persistence: Full database persistence
+- API: Uses n8n's NocoDB node with token authentication (ID: `6fNBtcghMe8wFoE5`)
+- Both workflows write to the same database table
+
+### Location Object Structure (NocoDB Schema)
+
+The NocoDB database uses the following schema for all location sources:
 
-### Location Object Structure
 ```json
 {
   "latitude": number,
@@ -49,6 +93,20 @@ The workflow has two main execution paths:
 }
 ```
 
+**Data Mapping for MQTT/OwnTracks**:
+- `latitude` ← `lat`
+- `longitude` ← `lon`
+- `timestamp` ← `tst` (Unix timestamp converted to ISO 8601)
+- `user_id` ← `0` (MQTT has no user ID)
+- `first_name` ← `tid` (tracker ID, e.g., "le")
+- `last_name` ← `source` (e.g., "fused")
+- `username` ← `tid`
+- `marker_label` ← Combination of `tid` and optionally `SSID`
+- `display_time` ← Formatted timestamp
+- `chat_id` ← `0` (MQTT has no chat ID)
+
+Additional MQTT data (accuracy, altitude, battery, velocity, etc.) is available in the transformation node but not stored in the database.
+
 ### API Response Structure
 ```json
 {
@@ -61,34 +119,115 @@ The workflow has two main execution paths:
 ```
 
 ### Web Interface
-The workflow sends users a link to `https://web.unixweb.home64.de/tracker/index.html` for viewing locations on a map. This frontend is hosted separately and not included in this repository.
+The workflow sends users a link to `https://web.unixweb.home64.de/tracker/index.html` for viewing locations on a map.
+
+The `index.html` file in this repository provides a standalone web interface:
+- **Map Library**: Leaflet.js (loaded from CDN)
+- **API Endpoint**: Configured to `https://n8n.unixweb.eu/webhook/location` (index.html:85)
+- **Features**: Auto-refresh (5 second interval), location history polyline, marker popups
+- **Hosting**: Can be hosted on any web server or opened as a local file
 
 ## Workflow Configuration
 
-- **Telegram Credentials**: Uses "Telegram account n8n-munich-bot" (ID: dRHgVQKqowQHIait)
+### Shared Configuration (Both Workflows)
+- **Telegram Credentials**: "Telegram account n8n-munich-bot" (ID: `dRHgVQKqowQHIait`)
 - **Webhook IDs**:
   - Telegram trigger: `telegram-location-webhook`
   - Location API: `location-api-endpoint`
-- **Error Workflow**: ID `PhwIkaqyXRasTXDH` (configured but not included in this export)
 - **Execution Order**: v1
 - **Caller Policy**: workflowsFromSameOwner
+- **Status**: Both workflows set to `active: true` by default
 
-## Modifying the Workflow
+### tracker.json Specific
+- **Storage**: Shell commands (cat, echo) for file I/O
+- **Error Workflow**: ID `PhwIkaqyXRasTXDH` (configured but not in this export)
 
-When editing this workflow:
-1. The workflow is active by default - test changes carefully to avoid disrupting live tracking
-2. JavaScript code nodes use n8n's code execution environment (not vanilla Node.js)
-3. Shell commands execute in n8n's runtime environment - ensure `/tmp` is writable
-4. CORS is configured for `*` (all origins) - restrict if needed for security
-5. Date formatting uses `de-DE` locale - adjust if different locale needed
-6. The 100-entry limit prevents unbounded growth - increase if more history is needed
+### tracker-db.json Specific
+- **NocoDB Credentials**: "NocoDB Token account" (ID: `6fNBtcghMe8wFoE5`)
+- **Project ID**: `pdxl4cx4dbu9nxi`
+- **Table ID**: `m8pqj5ixgnnrzkg`
+- **Sort Order**: Uses array structure `[{field: "timestamp", direction: "desc"}]` for sorting locations
 
-## Deployment
+### tracker-mqtt.json Specific
+- **MQTT Credentials**: Requires MQTT broker credentials (placeholder ID: `MQTT_CREDENTIAL_ID`)
+- **Topic**: `owntracks/#` (subscribes to all OwnTracks topics)
+- **Message Filter**: Only processes messages with `_type: "location"`
+- **NocoDB Config**: Same as tracker-db.json (shares database)
+- **Status**: Set to `active: false` by default (activate after configuring MQTT credentials)
 
-To use this workflow:
-1. Import `tracker.json` into n8n instance
-2. Configure Telegram bot credentials
-3. Ensure n8n has write permissions to `/tmp/n8n-locations.json`
+## Modifying the Workflows
+
+### Important Considerations
+1. **Both workflows are active by default** - test changes carefully to avoid disrupting live tracking
+2. **JavaScript code nodes** use n8n's execution environment (not vanilla Node.js)
+3. **Date formatting** uses `de-DE` locale - change in "Location verarbeiten" node if needed
+4. **CORS** is configured for `*` (all origins) - restrict for production security
+
+### tracker.json Specific
+- Shell commands execute in n8n's runtime environment - ensure `/tmp` is writable
+- The 100-entry limit prevents unbounded growth - adjust in "Merge mit History" node
+- Consider moving from `/tmp` to persistent storage for production (see README.md)
+
+### tracker-db.json & tracker-mqtt.json Specific
+- NocoDB sorting requires array structure: `[{field: "timestamp", direction: "desc"}]`
+- No client-side entry limit (relies on database capacity)
+- Requires valid NocoDB credentials and accessible database
+- Both workflows write to the same NocoDB table
+
+### tracker-mqtt.json Specific
+- Requires MQTT broker configuration before activation
+- Topic pattern can be adjusted to match your MQTT setup
+- Data transformation maps OwnTracks format to NocoDB schema
+- MQTT data fields (accuracy, battery, velocity) are extracted but not persisted to database
+
+### Common Modifications
+
+**Change history limit (tracker.json only)**:
+In "Merge mit History" node, change `locations.slice(0, 100)` to desired limit
+
+**Change date format**:
+In "Location verarbeiten" node, change `.toLocaleString('de-DE')` to desired locale
+
+**Restrict CORS**:
+In "Webhook - Location API" node, change `Access-Control-Allow-Origin: *` to specific domain
+
+**Update web interface URL**:
+In "Telegram Bestätigung" node and `index.html:85`, update API endpoint URL
+
+## Repository Contents
+
+- **tracker.json** - Telegram with file-based storage (simple, no database)
+- **tracker-db.json** - Telegram with NocoDB storage (production-ready)
+- **tracker-mqtt.json** - MQTT/OwnTracks with NocoDB storage (IoT devices)
+- **index.html** - Leaflet.js web interface for map visualization
+- **locations-example.csv** - Example data format for testing
+- **README.md** - Detailed German documentation with setup and usage instructions
+
+## MQTT/OwnTracks Integration
+
+The **tracker-mqtt.json** workflow is designed for OwnTracks-compatible MQTT location data.
+
+### Setup Requirements
+1. Configure MQTT broker credentials in n8n
+2. Update the credential ID in tracker-mqtt.json (currently placeholder: `MQTT_CREDENTIAL_ID`)
+3. Import workflow into n8n
 4. Activate the workflow
-5. Send a location via Telegram to test the capture flow
-6. Access the webhook endpoint to verify API functionality
+
+### OwnTracks Configuration
+Configure your OwnTracks app/device to publish to the same MQTT broker:
+- **Topic pattern**: `owntracks/user/device` (workflow subscribes to `owntracks/#`)
+- **Mode**: MQTT
+- **Expected message format**: JSON with `_type: "location"`
+
+### Data Flow
+1. OwnTracks device publishes location to MQTT broker
+2. n8n MQTT trigger receives message
+3. Filter checks for `_type: "location"`
+4. Data transformation maps MQTT fields to NocoDB schema
+5. Location stored in same database as Telegram locations
+6. Available via same `/location` API endpoint
+
+### Distinguishing Data Sources
+In the database:
+- **Telegram entries**: Have real `user_id` and `chat_id` values, `first_name`/`last_name` from Telegram profile
+- **MQTT entries**: Have `user_id: 0` and `chat_id: 0`, use `tid` (tracker ID) in name fields