n8n Workflow Engine

n8n serves as the primary automation and orchestration platform within HALO, running as a containerized service on Nexus and coordinating multi-system operations through a distributed worker architecture backed by Redis. The workflow engine provides the intelligent glue between services, connecting user actions in Omnia to device control in Home Assistant and AI reasoning in Apollo.

Overview

The n8n workflow engine runs as multiple containers on Nexus, providing:

Visual workflow builder accessible through Traefik at https://halo.local/n8n
Multi-system integration across Home Assistant, Frigate, Apollo, and Omnia API
Event-driven automation responding to webhooks, MQTT messages, and scheduled triggers
Distributed worker processing through Redis queues for long-running tasks
PostgreSQL backend for workflow persistence and execution history

Architecture

n8n operates in a main + worker configuration:

Main Container: Serves the web UI and manages workflow definitions. Accessible through Traefik reverse proxy with authentication middleware.

Worker Containers: Process background jobs from Redis queues, enabling long-running workflows without blocking the main UI or other workflows.

Redis Integration: Queue-based task distribution enables horizontal scaling and fault tolerance. Workers pull jobs from Redis queues and report results back.

PostgreSQL Storage: Workflow definitions, execution history, credentials, and configuration stored in dedicated schema within shared Nexus PostgreSQL instance.

Configuration

n8n configuration is managed through:

Docker Compose: nexus/compose/n8n.yml defines main and worker containers
Environment Variables: Database connection, Redis URL, webhook base URL, encryption keys
Volume Mounts: Custom nodes, workflow files, data persistence

Integration Points

n8n workflows integrate with all HALO services through various methods:

Home Assistant

REST API Calls: Control devices, query states, trigger scenes and scripts
WebSocket: Subscribe to real-time state changes and events
MQTT Subscription: React to device events published to Mosquitto broker
Webhook Triggers: Home Assistant automations can trigger n8n workflows

Frigate

REST API: Query events, retrieve snapshots, access recordings
MQTT Events: Subscribe to object detection events in real-time
Camera Control: Request snapshot captures, adjust detection zones

Apollo (Separate Hardware)

HTTP API Calls: Send prompts for AI reasoning over local network
Tool Invocation: Trigger Apollo to execute multi-step AI-assisted operations
Context Sharing: Pass workflow state to Apollo for context-aware responses

Omnia API

Widget Data: Update widget states and content
User Actions: Process user input from Omnia (Screen) dashboard
Notifications: Push updates to dashboard in real-time

Workflow Patterns

Common automation patterns implemented in n8n:

Scheduled Tasks: Daily summaries, routine maintenance, backup jobs

Event-Driven: MQTT device events, camera detections, webhook triggers

Multi-System Coordination: Morning routines coordinating lights (HA), notifications (Omnia), and AI suggestions (Apollo)

Data Transformation: API response mapping, format conversion, enrichment

Error Handling: Retry logic with exponential backoff, fallback workflows, alert escalation

Access & Management

Web Interface: https://halo.local/n8n (Traefik-proxied)
API: RESTful API for programmatic workflow management
CLI: n8n command-line tools for export, import, and migrations