> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ariscomfort.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Get FCU online/offline status

> Returns connection status for all FCUs.



## OpenAPI

````yaml get /api/fcus/status/all
openapi: 3.1.0
info:
  title: Aris API
  version: 1.0.0
  description: >
    REST API for controlling Aris home comfort systems.


    Aris is an air-to-water heat pump system that heats, cools, and provides hot
    water for homes.

    The Aris Brain is the central controller, managing zones, fan-coil units
    (FCUs), heat pumps,

    domestic hot water (DHW), and thermal energy storage (TES).


    ## Base URL


    The Aris Brain runs on your local network. Find your Brain's address via:

    - mDNS: `http://aris.local` (if your network supports mDNS)

    - Router admin panel: Look for a device named "aris-brain"


    ## Authentication


    Most API endpoints require authentication via Bearer token. Create an API
    token in the Aris web UI under **Settings → API Tokens**.


    Include the token in the `Authorization` header:

    ```

    Authorization: Bearer your-api-token

    ```


    ## Real-time Updates


    For real-time updates, connect to the WebSocket at
    `ws://aris.local?token=YOUR_API_TOKEN`.

    The WebSocket broadcasts zone state changes, system events, and device
    telemetry.
servers:
  - url: http://aris.local
    description: Local network (mDNS)
  - url: http://{brainIp}
    description: Local network (IP address)
    variables:
      brainIp:
        default: 192.168.1.100
        description: Your Aris Brain's IP address
security: []
tags:
  - name: Health
    description: Health check and readiness endpoints
  - name: System
    description: System-wide state and mode control
  - name: Zones
    description: Zone management, setpoints, and temperature control
  - name: DHW
    description: Domestic Hot Water tank status and history
  - name: TES
    description: Thermal Energy Storage tank status
  - name: HCU
    description: Hydronic Control Unit status
  - name: Heat Pumps
    description: Heat pump telemetry and diagnostics
  - name: FCUs
    description: Fan Coil Unit telemetry and status
  - name: Weather
    description: Weather data and forecasts
  - name: Events
    description: System event log and audit trail
  - name: Metrics
    description: VictoriaMetrics time-series data proxy
  - name: Prometheus
    description: Prometheus-compatible API for Grafana
  - name: Tokens
    description: API token management
  - name: Config
    description: System configuration (read-only)
  - name: Firmware
    description: FCU firmware OTA updates
paths:
  /api/fcus/status/all:
    get:
      tags:
        - FCUs
      summary: Get FCU online/offline status
      description: Returns connection status for all FCUs.
      operationId: getFCUStatusAll
      responses:
        '200':
          description: FCU status list
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: array
                    items:
                      type: object
                      properties:
                        fcuId:
                          type: string
                        friendlyName:
                          type: string
                        online:
                          type: boolean
                        lastSeen:
                          type: string
                          format: date-time
        '401':
          $ref: '#/components/responses/Unauthorized'
      security:
        - bearerAuth: []
components:
  responses:
    Unauthorized:
      description: Missing or invalid authentication
      content:
        application/json:
          schema:
            type: object
            properties:
              error:
                type: string
                example: Unauthorized
              message:
                type: string
                example: Valid authentication required
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Session token or API token

````