Home Assistant × Joulo

Charging sessions, ERE and status in Home Assistant

Joulo provides a REST API with the same data as your dashboard. A single YAML block in your configuration.yaml gives you sensors for charging status, kWh per session, total ERE credits and the active TAG ID.

REST

Bearer token

JSON

No add-on needed

// what you get

Four data streams, one token

The Joulo REST API exposes three endpoints. On top of those you can build as many Home Assistant sensors as you need — status, energy, sessions and EVCC linking.

Realtime status

GET /chargers • status of each charger, whether it is actively charging and the kWh accumulated in the current session.

Sessions

GET /sessions • list of recent charging sessions with kWh, start and end time, and the ERE credits per session.

Energy & ERE

GET /energy • total charged kWh and accrued ERE credits. Ideal for single-number indicators on your dashboard.

EVCC TAG ID

current_session.id_tag • the RFID/TAG ID behind the active session. Paste it into EVCC so it knows which vehicle is charging.

// setup

Up and running in four steps

The integration uses Home Assistant's built-in rest: integration. No custom component, no HACS — just YAML.

01 • Generate API token

Log in to your Joulo dashboard and open the API tab. Activate the API and copy the token. It's read-only — Joulo cannot write to your Home Assistant.

02 • secrets.yaml

Paste the token into secrets.yaml under the key joulo_token. Configuration.yaml then references it safely as !secret joulo_token.

03 • configuration.yaml

Add the rest: block below. The three endpoints (chargers, energy, sessions) together expose every sensor you need.

04 • Restart Home Assistant

Do a full restart (not just YAML reload). After a minute the Joulo entities show up in Developer Tools → States.

// configuration

Copy-paste YAML

Paste this into your configuration.yaml. Change [0] to an index or slug if you run multiple chargers.

secrets.yaml

# secrets.yaml
joulo_token: "joulo_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

configuration.yaml

# configuration.yaml — Joulo sensors
rest:
  - resource: https://api.joulo.nl/functions/v1/api/chargers
    scan_interval: 60
    headers:
      Authorization: "Bearer !secret joulo_token"
    sensor:
      - name: "Joulo Charger Status"
        value_template: "{{ value_json.chargers[0].status }}"
      - name: "Joulo Is Charging"
        value_template: "{{ value_json.chargers[0].is_charging }}"
      - name: "Joulo Session kWh"
        value_template: >-
          {{ value_json.chargers[0].current_session.kwh_so_far | default(0) }}
        unit_of_measurement: "kWh"
        device_class: energy
      # RFID/TAG-ID van de actieve sessie — handig voor EVCC om
      # de auto achter de sessie te identificeren.
      - name: "Joulo Active TAG ID"
        value_template: >-
          {{ value_json.chargers[0].current_session.id_tag | default('') }}

  - resource: https://api.joulo.nl/functions/v1/api/energy
    scan_interval: 3600
    headers:
      Authorization: "Bearer !secret joulo_token"
    sensor:
      - name: "Joulo Total kWh"
        value_template: "{{ value_json.total_kwh }}"
        unit_of_measurement: "kWh"
        device_class: energy
      - name: "Joulo Total ERE"
        value_template: "{{ value_json.total_ere_credits }}"

  - resource: https://api.joulo.nl/functions/v1/api/sessions?limit=10
    scan_interval: 600
    headers:
      Authorization: "Bearer !secret joulo_token"
    sensor:
      - name: "Joulo Last Session kWh"
        value_template: "{{ value_json.sessions[0].kwh }}"
        unit_of_measurement: "kWh"
        device_class: energy
      - name: "Joulo Last Session ERE"
        value_template: "{{ value_json.sessions[0].ere_credits | default(0) }}"

// dashboard

Lovelace card in five lines

A basic entities card shows the key Joulo sensors. Swap for a gauge, history-graph or mini-graph card for a richer view.

ui-lovelace.yaml

# Lovelace dashboard kaart
type: entities
title: Joulo laadstation
entities:
  - entity: sensor.joulo_charger_status
    name: Status
  - entity: binary_sensor.joulo_is_charging
    name: Laadt nu
  - entity: sensor.joulo_session_kwh
    name: Huidige sessie
  - entity: sensor.joulo_total_kwh
    name: Totaal geladen
  - entity: sensor.joulo_total_ere
    name: ERE-credits

// automations

Two automation recipes

What you do with the data is up to you. Two common patterns you can use directly:

Push notification when session ends

# automations.yaml — notify wanneer sessie eindigt
- id: joulo_session_done
  alias: "Joulo • sessie afgerond"
  trigger:
    - platform: state
      entity_id: binary_sensor.joulo_is_charging
      from: "on"
      to: "off"
  action:
    - service: notify.mobile_app_jouw_telefoon
      data:
        title: "Laadsessie klaar"
        message: >-
          {{ states('sensor.joulo_session_kwh') }} kWh geladen.
          Totaal vandaag: {{ states('sensor.joulo_total_kwh') }} kWh.

EVCC vehicle ID via TAG ID

# evcc.yaml — gebruik de Joulo TAG-ID voor auto-identificatie
vehicles:
  - name: tesla
    type: template
    template: tesla
    identifiers:
      # Plak hier de waarde van sensor.joulo_active_tag_id na een
      # eerste laadsessie. EVCC herkent dan welke auto er laadt.
      - "DEADBEEF12345678"

// troubleshooting

If entities stay empty

401 Unauthorized

Token not copied correctly, or quotes wrap the token in secrets.yaml. Remove them, restart Home Assistant and check the log.

unavailable / unknown

value_template can't find the value — usually because no session is active yet. Use | default(0) or | default('') as in the example.

Multiple chargers

The response is an array. Replace chargers[0] with chargers[1], or filter by slug with chargers | selectattr('slug', 'eq', 'my-charger') | first.

Rate limiting

Keep scan_interval at 60 s or higher for /chargers and 600 s or higher for /sessions and /energy. Polling faster doesn't give you more data — Joulo syncs from the upstream provider every 15 min.

proxy.joulo.nl (guide)

Hosted OCPP proxy: WebSocket URL, CSMS + Joulo.

Joulo for developers

Overview of all tools, APIs and integrations.

OCPP connection

Connect any OCPP 1.6J charger to Joulo.

OCPP Proxy / Splitter

Open-source proxy for multiple backends.

Hosted OCPP Proxy

Use proxy.joulo.nl without self-hosting.

OCPP API

OCPP WebSocket integration and configuration.

Platform status

Realtime status of all Joulo services.

Developer Docs

Quickstart, authentication, guides and REST API reference.

status.joulo.nl