In certain special cases it might be desired to avoid placing any middleware like an MQTT or a home automation server just to transfer small bits of data from one node to another. Direct data polling is possibvle using HTTP, but beware that the involved components are resource hungry and may be less stable on long term. The webserver embedded in the node is not designed to constantly serve a large amount of requests.
Setting up a webserver using the :doc:`/components/web_server` on the primary node will make available the required sensor data through a :ref:`api-rest` interface.
On the client nodes we need an :doc:`/components/http_request` with an ``id`` set, and a :doc:`/components/sensor/template` to make it accessible locally.
To automate the request for data, we use an :ref:`interval` requesting the URL pointing to the sensor id for which the state is needed. See :ref:`api-rest` on how to build up the URL for your sensors.
In the example below we request the value of a sensor from the server node, and after parsing the resulted JSON string we publish it to the local template sensor: