Do I need an API key for Home Assistant?

No. The InfraNode API is keyless and free. The REST sensor calls the URL directly, without headers or tokens.

How often can I poll?

The rate limit is 300 requests per minute per IP. A scan_interval of 1800 seconds (30 minutes) is more than enough for environmental data and is gentle on the source.

Which cities are supported?

84 major German cities. Just replace berlin in the path with your city slug from the cities overview.

Use German open city data in Home Assistant

Step-by-step guide: bring weather, air quality and electricity price for your city into Home Assistant as a sensor through the free, keyless InfraNode API.

Why InfraNode for Home Assistant

To couple smart home automations to real environmental data you need a source that works without sign-up and returns stable JSON. InfraNode bundles open data for 84 major German cities behind a free, keyless REST API. Every response carries source, license and timestamp, so you can filter reliably in Home Assistant.

Air quality as a REST sensor

Add the following sensor to your configuration.yaml. It reads the PM10 value from the envelope under data.payload:

# configuration.yaml
sensor:
  - platform: rest
    name: Air quality Berlin
    resource: https://infranode.dev/api/v1/cities/berlin/air-uba
    method: GET
    value_template: "{{ value_json.data.payload.pm10 }}"
    unit_of_measurement: "ug/m3"
    scan_interval: 1800

Electricity price for dynamic tariffs

The nationwide day-ahead spot price is ideal for shifting loads like a wallbox or heat pump into cheaper hours:

  - platform: rest
    name: Day ahead electricity price
    resource: https://infranode.dev/api/v1/cities/berlin/power-price
    method: GET
    value_template: "{{ value_json.data.payload.value }}"
    unit_of_measurement: "EUR/MWh"
    scan_interval: 3600

Use the value as a condition in an automation, for example "only charge the car when the price is below X".

Understand the envelope

All domain data sits under data.payload, metadata such as source and cache status under meta. Inspect a raw response:

curl https://infranode.dev/api/v1/cities/berlin/weather

The data types are described on the pages for weather, air quality and electricity price. Find the slug for your city in the cities overview.

Frequently asked questions

Do I need an API key for Home Assistant?: No. The InfraNode API is keyless and free. The REST sensor calls the URL directly, without headers or tokens.
How often can I poll?: The rate limit is 300 requests per minute per IP. A scan_interval of 1800 seconds (30 minutes) is more than enough for environmental data and is gentle on the source.
Which cities are supported?: 84 major German cities. Just replace berlin in the path with your city slug from the cities overview.